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Oligohydramnios
Introduction
Oligohydramnios is defined as decreased amniotic fluid volume (AFV) for gestational age and is associated with increased rates of neonatal morbidity. AFV is typically assessed via transabdominal ultrasound using either the amniotic fluid index (AFI) or the single deepest vertical pocket (DVP) techniques. Oligohydramnios is defined as an AFI ≤5 cm or DVP, also referred to as the maximum vertical pocket (MVP) or single deepest pocket (SDP), <2 cm.[1][2]
Oligohydramnios develops when the mechanisms that regulate AFV are disrupted. Most often, this is due to reduced fetal urination, uteroplacental insufficiency, or loss of amniotic fluid with membrane rupture. However, in many cases, an etiology is never identified.[3][4] As oligohydramnios is a symptomatic reflection of an underlying etiology, patients should be evaluated to identify the abnormal condition resulting in low AFV.
Oligohydramnios assessment comprises a targeted history and physical examination, detailed ultrasound imaging, and amniocentesis for genetic testing if fetal anomalies or history-based risk factors are identified. The management and prognosis of oligohydramnios primarily depend on the underlying pathophysiology and the gestational age at diagnosis. Increased antepartum surveillance and early delivery are typically indicated in patients with idiopathic disease.
Etiology
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Etiology
Physiology of Amniotic Fluid Volume Regulation
In general, the AFV results from the balance of fluid production and fluid reabsorption.
Amniotic fluid production
In the first trimester of pregnancy, lung secretions and hydrostatic and osmotic transport of maternal plasma through the fetal membranes comprise the majority of amniotic fluid production. Between 14 and 16 weeks gestation, the fetal kidneys begin to produce urine, which becomes the primary source of amniotic fluid for the remainder of the gestation.[5]
Fetal urine is produced at a relatively steady rate, and this rate increases throughout most of pregnancy as the fetus grows. The estimated hourly fetal urine production rates for fetuses at 20, 30, and 40 weeks are 4.2, 22.7, and 52.2 mL/hr, respectively, equivalent to approximately 100 mL/day, 545 mL/day, and 1,250 mL/day.[6][7] This rate is often higher than average in larger fetuses and tends to be lower than average in growth-restricted fetuses.[8]
Amniotic fluid reabsorption
The majority of amniotic fluid reabsorption occurs via fetal swallowing of fluid and absorption through the gastrointestinal tract. Direct absorption into the fetal blood vessels perfusing the fetal surface of the placenta also plays a role.[5][9] Like urine production, fetal swallowing increases throughout pregnancy as swallowing movements become progressively more coordinated.[10] The fetus is estimated to swallow 500 mL to 1000 mL of amniotic fluid daily at a term gestational age.[11] Animal evidence suggests that swallowing also increases as AFV increases, which appears to be an important regulator of AFV.[12] The intramembranous pathway removes an additional 200 to 500 mL of fluid per day.[7]
Amniotic fluid level changes with gestational age
As production and absorption levels change, the AFV also changes throughout gestation.[13] Those with lower AFV often continue to steadily increase their AFV until 41 weeks gestation, peaking at an AFV of <400 mL before declining in the late-term and postterm. On the other hand, those with higher AFV may reach their peak AFV as early as 29 to 30 weeks, with volumes ranging from 1 to 5 L. In these patients, AFV then tends to decline to approximately 740 to 800 mL by 41 weeks.[14] Because the AFV begins to decrease late in gestation, a reduced AFV is often noted in postterm gestations.
Etiologies of Oligohydramnios
Prelabor rupture of membranes (PROM) is a common cause of oligohydramnios, especially in the second trimester.[15][16][3][4] Oligohydramnios is also seen in a higher percentage of postterm pregnancies due to the natural decline in amniotic fluid production near term, as previously described.
Congenital anomalies are found in approximately 50% of patients diagnosed with oligohydramnios in the second trimester.[16] Considering the physiology of AFV regulation, the primary fetal anomalies associated with oligohydramnios are those that reduce fetal urine production. This includes numerous fetal genitourinary abnormalities, eg, bladder outlet obstruction, dysplastic kidneys, and renal agenesis.[3] Chromosomal abnormalities are also more common. Congenital infections, including TORCH organisms (Toxoplasma, rubella, cytomegalovirus, herpes simplex) and parvovirus B19, are less common causes of oligohydramnios and are typically associated with other abnormalities.
Oligohydramnios is also associated with pathologies that cause (or result from) uteroplacental insufficiency, including fetal growth restriction (FGR), hypertensive disorders, chronic placental abruption, and maternal microvascular disease (eg, diabetic nephropathy). Additionally, maternal use of numerous medications can reduce fetal renal blood flow, including angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and nonsteroidal anti-inflammatory drugs (NSAIDs).[17]
Twin-twin transfusion syndrome (TTTS) is a serious potential complication of monochorionic twin gestations that affects 8% to 10% of these pregnancies.[18][19] In this condition, vascular connections within the monochorionic placenta result in the shunting of blood from 1 twin (the donor) to the other (the recipient). This redistribution of blood flow can lead to severe volume depletion and oligohydramnios in the donor twin, while the recipient may experience fluid overload, hydrops fetalis, and high-output cardiac failure.[18][19][20]
Increased swallowing is not a major cause of oligohydramnios; however, fetal swallowing decreases when AFV decreases, which may help protect the fetus from developing oligohydramnios.[21][12][22]
Epidemiology
The incidence of oligohydramnios is <1% in preterm pregnancies.[23][24] However, rates appear slightly higher in patients with preterm labor and intact membranes, at 2.6%.[25] Prevalence rates begin to increase as the pregnancy approaches 39 weeks gestation.
A large, population-based Norwegian cohort found that between 37 and 39 weeks gestation, the prevalence rate of oligohydramnios is around 1.1%, and this rate steadily increases to approximately 1.3% by 39 weeks, 1.7% by 40 weeks, 2.7% by 41 weeks, and then jumps to 4.4% by 42 weeks gestation.[26] Another large cross-sectional study of 112,424 births from 39 hospitals across China found that 4.4% of all term deliveries (defined as ≥37 weeks gestation) were complicated by oligohydramnios.[23] Additionally, the prevalence of oligohydramnios may be higher in lower-resource areas, with a 2022 study showing a prevalence rate of 9.4% in patients at least 36 weeks gestation.[27]
History and Physical
Clinical Presentation
Patients with oligohydramnios are often asymptomatic, although their presentation may vary depending on the underlying cause. The following are examples of presentations associated with oligohydramnios:
- Patients with preterm prelabor rupture of membranes (PPROM) often present with leakage of fluid.
- Patients with oligohydramnios due to uteroplacental insufficiency resulting from pregnancy-related hypertensive disorders may present with hypertension, headache, vision changes, dyspnea, or right upper quadrant or epigastric pain.
- Patients with a chronic placental abruption often have cramping abdominal pain and vaginal bleeding.
- Patients may be carrying a fetus with known congenital anomalies or chromosomal abnormalities, diagnosed on routine screening tests in the first and second trimesters, which increases their risk for oligohydramnios.
- Patients with congenital infections may present with fever, characteristic lesions, a history of recent exposure, or abnormal ultrasound findings on routine screening.
Clinical History
When oligohydramnios is suspected or confirmed, a focused history should assess the patient for risk factors, signs, and symptoms of potential underlying etiologies, including asking about leakage of fluid, vaginal bleeding, contractions, fetal movement, and symptoms of pregnancy-related hypertension and potential congenital infections (eg, recent sick contacts, recent rash or fever, history of herpes outbreak).
Clinicians reviewing the patient's medical history should look for conditions that may lead to maternal microvascular disease, eg, diabetic nephropathy or autoimmune disease. The family history can help determine a patient's risk of carrying a fetus with congenital anomalies and a genetic condition. The patient's medications should also be reviewed for possible causative agents.
Physical Examination
Obtaining serial fundal height measurements is a standard component of routine prenatal care. The fundal height is determined by measuring from the pubis symphysis to the top of the uterine fundus. The fundal height in centimeters should be within 3 cm of the gestational age in weeks. Oligohydramnios should be considered when the fundal height is lower than expected. A fetal growth ultrasound assessing AFV is generally recommended when the fundal height is at least 3 cm smaller (or larger) than expected.
Patients presenting with symptoms suggestive of a specific condition associated with oligohydramnios should be evaluated appropriately. For example, patients who present with leakage of fluid or vaginal bleeding require a speculum exam, while those presenting with hypertension require a neurologic, pulmonary, and abdominal exam as part of their evaluation to assess for hypertensive disorders of pregnancy. Please see StatPearls' companion resource, "Hypertension in Pregnancy," for further information on these conditions.
Evaluation
Initial Diagnostic Evaluation of Oligohydramnios
The diagnosis of oligohydramnios is made by ultrasound imaging. Therefore, a targeted obstetric ultrasound that assesses AFV is indicated in all patients at risk of oligohydramnios. The following clinical findings are indications for ultrasound evaluation:
- Patients with a fundal height that is at least 3 cm smaller than expected for gestational age
- Known fetal structural abnormalities in the genitourinary tract or gastrointestinal tract
- Markers, screening results, or genetic testing consistent with fetal aneuploidy
- Patients at risk for uteroplacental insufficiency (eg, patients with pregnancy-related hypertension, pregestational diabetes mellitus, and chronic placental abruption)
Methods of assessment
Oligohydramnios should be diagnosed based on a quantitative sonographic assessment of AFV. Amniotic fluid is best evaluated by 2 methods: 1) by measuring the single DVP of amniotic fluid (sometimes called the MVP or SDP) or 2) by calculating the AFI, which represents the quantitative sum of the DVP measurements obtained in each of the 4 abdominal quadrants. According to a significant 2014 interprofessional workshop by the United States National Institute of Child Health and Human Development (NICHD) and numerous coordinating professional organizations, including the Society for Maternal-Fetal Medicine (SMFM), measured pockets must be at least 1 cm wide and free of umbilical cord and fetal parts.[28] A normal DVP is ≥2 cm and <8 cm, while a normal AFI is >5 cm and <24 cm.
Notably, both AFI and DVP correlate relatively poorly with actual AFV as measured by dye dilution tests, which are still considered the gold standard for determining quantitative AFV.[29] However, similar to dye dilution tests, abnormal AFIs and DVPs are associated with adverse outcomes; therefore, noninvasive sonographic assessments of AFV are recommended for diagnosing and monitoring AFV abnormalities.[30][31]
Amniotic fluid measurement technique
The following ultrasound techniques should be considered to obtain accurate amniotic fluid measurement:
- Transducer placement: To accurately measure a pocket of amniotic fluid, professional guidelines recommend positioning the ultrasound transducer perpendicular to the floor while scanning in the sagittal plane (ie, parallel to the spine).[30][31] However, newer data suggest that the transducer may also be placed perpendicular to the uterine contour.[32]
- Color doppler: Color Doppler can aid in detecting umbilical cord and fetal parts that may be present within a fluid pocket. Studies have shown that the addition of color Doppler decreases both AFI and DVP measurements by approximately 20%.[33][34] A prospective study assessing perinatal outcomes in patients with abnormal AFV, with and without color Doppler, found that the addition of color Doppler did not alter outcomes.[35] Another study found that the use of color Doppler led to an overdiagnosis of oligohydramnios compared to dye dilation techniques.[36]
- DVP versus AFI: The DVP must be used in multifetal gestations, as assessing all 4 abdominal quadrants for each fetus is impossible. In singleton gestations, either DVP or AFI can be used to diagnose oligohydramnios; however, DVP has a higher positive predictive value (PPV) for oligohydramnios than AFI.[37] Multiple randomized controlled studies have demonstrated that the use of DVP for the diagnosis of oligohydramnios is associated with fewer obstetric interventions without a significant difference in perinatal outcomes.[38][39][40] Therefore, professional societies, including the Society for Maternal Fetal Medicine (SMFM), the American College of Obstetricians and Gynecologists (ACOG), and the American Institute of Ultrasound in Medicine (AIUM), recommend the use of DVP over AFI.[1] Evidence also suggests that AFI may overestimate AFV when AFV is low, while underestimating AFV when AFV is high, leading to a reduction in interventions for mild idiopathic polyhydramnios.[35][41][42][29]
Evaluation of Oligohydramnios Etiologies
Once oligohydramnios is diagnosed, an evaluation should attempt to identify an underlying etiology. This evaluation begins with reviewing the prenatal record, obtaining a detailed medical history, and performing a targeted obstetric ultrasound.
Routine screening tests
Routine prenatal care includes screening for numerous potential underlying etiologies of oligohydramnios, including aneuploidy, congenital anomalies (identified through a mid-trimester ultrasound), and susceptibility to rubella and varicella. Appropriate laboratory testing should be ordered if not yet completed. In monochorionic twin gestations, SMFM recommends screening for TTTS every 2 weeks, starting at 16 weeks of gestation and continuing through delivery.[18]
Rupture of membranes assessment
Membrane status must be determined in all patients with oligohydramnios. Further testing is warranted if the status is unclear based on the exam alone, including obtaining a sample of vaginal secretions to look for ferning on microscopy, testing the fluid's pH with nitrizine paper, or using point-of-care diagnostic tests for amniotic fluid proteins.[43]
Targeted obstetric ultrasound
A targeted ultrasound should be performed to assess fetal growth and look for fetal anomalies that may suggest a cause of the oligohydramnios. The urologic tract should be evaluated carefully. The presence of both kidneys should be documented, along with their location, size, shape, echogenicity, and the presence of cysts or dilation. When the renal vessels are not well visualized, color Doppler is used to help confirm the diagnosis of renal agenesis. The bladder should also be carefully evaluated. Failure to visualize the bladder suggests renal agenesis, while an enlarged bladder with thickened walls suggests bladder outlet obstruction (eg, posterior urethral valves). The fetus should also be evaluated for soft markers and anomalies consistent with aneuploidy and known genetic syndromes. An estimated fetal weight should also be obtained, as oligohydramnios is frequently associated with fetal growth restriction (FGR).
Diagnostic genetic testing
Diagnostic genetic testing is appropriate in patients with congenital anomalies identified on the targeted ultrasound in the setting of oligohydramnios. The primary options include chromosomal microarray analysis (CMA), exome sequencing, and targeted gene panels. CMA can detect small deletions and duplications and is currently recommended as the initial genetic test (over a conventional karyotype) in most cases.[44] However, in the absence of anomalies or increased aneuploidy risk on screening tests, idiopathic oligohydramnios does not increase the detection rate of genetic abnormalities by CMA above baseline.[45][46]
On the other hand, exome sequencing may be associated with higher detection rates of pathogenic genetic variants in both idiopathic oligohydramnios and oligohydramnios associated with other abnormal ultrasound findings. In a 2023 retrospective study of 126 patients with oligohydramnios, 7 of the 32 patients who underwent exome sequencing were found to have a pathogenic or likely pathogenic variant.[46] Of these 7 patients, 2 had idiopathic disease, while 5 had associated renal anomalies.
The most common anomalies detected by exome sequencing in that study included variants involving the renin-angiotensin-aldosterone system that lead to autosomal recessive renal tubular dysgenesis. Currently, the American College of Medical Genetics and Genomics (ACMG) recommends considering exome sequencing only for pregnancies with fetal structural anomalies when the CMA or karyotype is normal; however, targeted gene panels should be considered when a specific diagnosis is suspected.[47]
Testing for congenital infection
TORCH infections are a relatively uncommon cause of oligohydramnios and are usually associated with additional findings. Appropriate serologies are indicated only if an infection is clinically suspected based on a patient's history, examination, or ultrasound findings.
Treatment / Management
Antepartum Monitoring
Antepartum care and delivery timing should be managed according to the identified underlying etiology of oligohydramnios (eg, PPROM, placental abruption, FGR, and anomalies). The following monitoring methods may be utilized to assess fetal condition and guide management decisions:
- Antepartum fetal surveillance (AFS): In patients with isolated oligohydramnios, the American College of Obstetricians and Gynecologists (ACOG) suggests initiating AFS once or twice weekly, starting at diagnosis (or at a gestational age when delivery would be considered due to abnormal results) and continuing until delivery.[48] AFS often consists of a nonstress test (NST) and assessment of the AFV with either a DVP or AFI; together, these tests are considered a modified biophysical profile (BPP). Alternatively, a complete BPP can be used.
- Growth ultrasounds: Due to the association between oligohydramnios and FGR, serial growth ultrasounds are typically performed every 3 to 4 weeks.
- Doppler velocimetry: Doppler velocimetry of the umbilical artery is not indicated in patients with isolated oligohydramnios, normal-appearing kidneys on ultrasound, and normal tests of fetal well-being. However, in the setting of FGR, assessment of the severity of uteroplacental insufficiency, regardless of the AFV, is recommended.[49][48][50] (B3)
Antepartum Treatment
Various antenatal management approaches may be used in pregnancies with oligohydramnios.
Maternal hydration
Maternal hydration increases AFV. Most studies have evaluated hydration by giving patients between 1.5 and 2.5 L of fluid. Studies have shown that both intravenous (IV) and oral hydration improve AFV, although oral hydration appears to have a slightly greater effect on AFV than IV hydration.[51][52] Oral hydration with 2 L of fluid has been shown to increase the AFI by a mean of 3.8 to 5 cm, while IV hydration with 2 L of hypotonic fluid can increase AFI from 2.8 to 3.8 cm.[52][53][51][54]
Improvements in AFV appear to be more dependent on the duration of therapy rather than the dose.[55] A single episode of maternal hydration improves the AFI in the immediate short term, though the effect is often gone by 24 hours.[56][57] However, longer-term improvements in AFI are noted when daily maternal hydration is maintained.[58] Furthermore, the improvements in AFI associated with maternal hydration also appear to reduce cesarean birth rates to rates comparable to those of normal pregnancies.[59] (A1)
Limited data are available on perinatal outcomes following hydration interventions. Some evidence suggests that the initiation of oral rehydration therapy in isolated oligohydramnios is associated with higher birth weights, placental weights, and improved APGAR scores.[60] Based on the available data, it seems reasonable to recommend oral hydration with 1500 mL to 2000 mL of hypotonic fluid daily for at least 2 weeks. (A1)
Vesicoamniotic shunt
A vesicoamniotic shunt can be considered in patients with oligohydramnios diagnosed between 16 and 28 weeks of gestation due to suspected lower urinary tract obstruction (LUTO) in the absence of life-limiting anomalies.[61] A 2024 international consensus committee on LUTO notes that the goal of shunt placement is to improve the chance of perinatal survival and that prenatal surgical intervention is preferred for the treatment of fetal LUTO.[61] Due to the inherent risks of fetal surgery, at this time, vesicoamniotic shunt placement should be limited to patients treated at major referral centers.(B3)
Amnioinfusion
Serial percutaneous transabdominal amnioinfusion and continuous amnioinfusion through a port have been studied in patients with severe oligohydramnios diagnosed in the second trimester, including patients with isolated oligohydramnios, early PPROM, and fetal renal disease or bladder outlet obstruction. However, data regarding perinatal outcomes are mixed. Several randomized controlled trials showed no improvement in perinatal mortality or latency periods in patients with mid-trimester PPROM treated with serial amnioinfusion.[62] In patients with suspected LUTO, the same international consensus committee referenced above stated that serial amnioinfusion should only be offered in an experimental setting.[61](A1)
Delivery Timing
If underlying pathology is present, the delivery timing should be based on recommendations for the patient's specific underlying condition. In patients with isolated oligohydramnios, the ACOG recommends delivery between 36 0/7 and 37 6/7 weeks gestation or at the time of diagnosis if diagnosed at or beyond 38 weeks gestation.[63](B3)
Intrapartum Management
Continuous electronic fetal monitoring (EFM) is recommended in patients with FGR, which frequently coexists with oligohydramnios, and for patients undergoing induction of labor (IOL), which is usually indicated for patients with oligohydramnios. Experts also often use continuous EFM for patients with isolated oligohydramnios.
Interestingly, a 2019 prospective cohort study found that EFM patterns in the 2 hours immediately preceding delivery in patients undergoing induction of labor at term with a diagnosis of oligohydramnios were similar to those in patients undergoing induction of labor at term without oligohydramnios.[64] In the oligohydramnios group, nearly 75% of patients had spontaneous vaginal delivery, and almost 84% had no periods of repetitive decelerations. In a subgroup analysis of patients with small-for-gestational-age (SGA) neonates, higher but similar rates of decelerations were observed in both the SGA with oligohydramnios and SGA without oligohydramnios groups compared to the groups with non-SGA neonates.
Older studies have demonstrated that prophylactic intrapartum amnioinfusion in patients with oligohydramnios significantly decreases rates of intrapartum fetal heart rate abnormalities, cesarean deliveries, acidemia at birth, and 5-minute APGAR scores <7.[65] (A1)
Differential Diagnosis
Oligohydramnios can result secondary to many complications of pregnancy;[66] these underlying etiologic diagnoses, which can be categorized into the following differentials:
- Maternal: Oligohydramnios is associated with various medical conditions that lead to uteroplacental insufficiency (8% of all gestations). Possible causes of uteroplacental insufficiency include chronic hypertension, vascular disease, thrombophilia, and preeclampsia. Oligohydramnios can also be associated with certain medications (eg, angiotensin-converting enzyme inhibitors, NSAIDs, and cocaine use) and maternal diabetes.[66]
- Fetal: Rupture of membranes is the most common obstetric cause for oligohydramnios. Preterm premature rupture of membranes alone accounts for >37% of oligohydramnios cases diagnosed in the second and third trimesters. Genitourinary tract abnormalities (eg, renal agenesis and obstructive nephropathy) are associated with oligohydramnios and occur at an incidence of 3 to 7 per 1000 live births. Postterm pregnancies, fetal growth restriction (5% of the second trimester and 20.5% of third-trimester diagnoses), chromosomal abnormalities (10% of oligohydramnios cases in the second trimester), and fetal demise are also associated with oligohydramnios.[16]
- Placental: Placental causes of oligohydramnios include abruption (8.6% of all oligohydramnios cases) and twin-twin transfusion syndrome (oligohydramnios-polyhydramnios sequence).[16]
- Idiopathic: The majority of oligohydramnios cases, accounting for 50.7% of diagnoses, occur in the third trimester and are typically associated with better outcomes.[16]
Prognosis
The management and prognosis of oligohydramnios vary greatly depending on the underlying etiology, the gestational age at diagnosis, and the severity of oligohydramnios. Specifically, patients with underlying genitourinary malformations, chromosomal abnormalities, and FGR have a worse prognosis than those with isolated oligohydramnios.[67][68] For example, in a retrospective cohort study of 131 fetuses with oligohydramnios due to renal abnormalities, 35% chose pregnancy termination, 8% had intrauterine fetal death, 27% had neonatal or postneonatal death, and 30% survived.[69]
Diagnosis of oligohydramnios during the second trimester is more likely to be associated with severe fetal anomalies or maternal disease, whereas diagnosis in the third trimester is more likely to be of unexplained origin. In an older study from 1996, the etiology of oligohydramnios was unexplained in just 4% of second-trimester gestations, whereas 52% of those diagnosed in the third trimester were idiopathic.[16] In this study, only 10.2% of fetuses diagnosed in the second trimester survived, and 60% were terminated due to poor prognosis. The survival rate was 85.3% when oligohydramnios was diagnosed in the third trimester of pregnancy.
In patients with oligohydramnios diagnosed in the second trimester, pulmonary hypoplasia is the most significant predictor of fetal mortality. Pulmonary hypoplasia is most severe when oligohydramnios develops before 26 weeks gestation, when the terminal sacs of the fetal lung are developing. Low AFV during the second and early third trimester also increases the likelihood of limb contractures and birth defects due to compression of fetal parts.
Complications
Severe oligohydramnios or anhydramnios in the second trimester can lead to intrauterine fetal death or previable or periviable birth. In addition, fetal compression inside the uterus can lead to a condition known as Potter sequence, which includes pulmonary hypoplasia, limb contractions, and flattened facies.[16]
Isolated oligohydramnios diagnosed in the third trimester is associated with increased rates of umbilical cord compression, abnormal fetal heart rate patterns, cesarean birth, meconium aspiration syndrome, and admission to the neonatal intensive care unit (NICU).[2][70]
Deterrence and Patient Education
Patient education regarding oligohydramnios should emphasize the importance of maintaining adequate maternal hydration and receiving routine prenatal care throughout pregnancy.
Patients should be advised that their total water requirement during pregnancy is approximately 3 L/day, which will help prevent oligohydramnios associated with maternal dehydration. On their website for patients, ACOG recommends drinking 64 to 96 fl oz (8 to 12 cups or 1.7 to 2.8 L) of water daily. Higher temperatures, physical activity, high altitude, low humidity, and illness increase total water requirements.[71]
Regular prenatal care enables the healthcare team to recognize and promptly diagnose oligohydramnios, as well as any underlying pathology. The clinical care team can then recommend appropriate antepartum monitoring and optimize delivery timing to minimize the risk of fetal and maternal complications associated with oligohydramnios.
Enhancing Healthcare Team Outcomes
The care and management of oligohydramnios require a collaborative, interprofessional approach to enhance patient-centered care, optimize outcomes, ensure patient safety, and improve team performance. Physicians, advanced practitioners, nurses, pharmacists, and other health professionals must work together seamlessly to address the complexities of this condition. Obstetricians or clinically trained midwives are often the first to suspect oligohydramnios during routine prenatal care when fundal height measurements appear lower than expected. These findings prompt obstetric ultrasound technicians to apply their diagnostic expertise by identifying oligohydramnios through standardized criteria and assessing potential underlying anomalies through detailed imaging.
Once diagnosed, maternal-fetal medicine specialists frequently contribute to the care of patients with more severe presentations or underlying pathologies by designing individualized care plans. When conditions such as second-trimester oligohydramnios, PPROM, or severe anomalies are present, neonatologists are pivotal in providing anticipatory guidance and support for expected neonatal outcomes. Additionally, genetics professionals may be consulted to evaluate potential hereditary or chromosomal disorders if suggested by clinical history or imaging findings.
Nurses are integral to patient care throughout the continuum, particularly during labor, as they monitor maternal and fetal status closely and address potential complications associated with oligohydramnios, such as umbilical cord compression or nonreassuring fetal heart tracings. Their vigilance at the bedside is critical to ensuring optimal outcomes for both the mother and neonate. Effective interprofessional communication and coordinated care strategies, including timely referrals and shared decision-making, are essential to managing the complexities of oligohydramnios while prioritizing patient safety and enhancing team performance.
References
. AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2018 Nov:37(11):E13-E24. doi: 10.1002/jum.14831. Epub 2018 Oct 11 [PubMed PMID: 30308091]
Rabie N, Magann E, Steelman S, Ounpraseuth S. Oligohydramnios in complicated and uncomplicated pregnancy: a systematic review and meta-analysis. Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. 2017 Apr:49(4):442-449. doi: 10.1002/uog.15929. Epub [PubMed PMID: 27062200]
Level 1 (high-level) evidenceNewbould MJ, Lendon M, Barson AJ. Oligohydramnios sequence: the spectrum of renal malformations. British journal of obstetrics and gynaecology. 1994 Jul:101(7):598-604 [PubMed PMID: 8043538]
Yang Z, Yao J, Yin Z, Yang Y, Wei Z. Amnioinfusion compared with expectant management in oligohydramnios with intact amnions in the second and early third trimesters. Acta obstetricia et gynecologica Scandinavica. 2024 Sep:103(9):1829-1837. doi: 10.1111/aogs.14888. Epub 2024 Jul 7 [PubMed PMID: 38973223]
Brace RA. Physiology of amniotic fluid volume regulation. Clinical obstetrics and gynecology. 1997 Jun:40(2):280-9 [PubMed PMID: 9199840]
Fägerquist M, Fägerquist U, Odén A, Blomberg SG. Fetal urine production and accuracy when estimating fetal urinary bladder volume. Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. 2001 Feb:17(2):132-9 [PubMed PMID: 11251922]
Sherer DM. A review of amniotic fluid dynamics and the enigma of isolated oligohydramnios. American journal of perinatology. 2002 Jul:19(5):253-66 [PubMed PMID: 12152144]
Seol HJ, Kim HY, Cho GJ, Oh MJ. Hourly fetal urine production rate in isolated oligohydramnios at term. PloS one. 2021:16(5):e0250659. doi: 10.1371/journal.pone.0250659. Epub 2021 May 21 [PubMed PMID: 34019576]
Gilbert WM, Brace RA. The missing link in amniotic fluid volume regulation: intramembranous absorption. Obstetrics and gynecology. 1989 Nov:74(5):748-54 [PubMed PMID: 2812652]
Grassi R, Farina R, Floriani I, Amodio F, Romano S. Assessment of fetal swallowing with gray-scale and color Doppler sonography. AJR. American journal of roentgenology. 2005 Nov:185(5):1322-7 [PubMed PMID: 16247157]
Ross MG, Nijland MJ. Fetal swallowing: relation to amniotic fluid regulation. Clinical obstetrics and gynecology. 1997 Jun:40(2):352-65 [PubMed PMID: 9199846]
Brace RA, Anderson DF, Cheung CY. Ovine fetal swallowing responses to polyhydramnios. Physiological reports. 2014:2(3):e00279. doi: 10.1002/phy2.279. Epub 2014 Mar 27 [PubMed PMID: 24760530]
Magann EF, Bass JD, Chauhan SP, Young RA, Whitworth NS, Morrison JC. Amniotic fluid volume in normal singleton pregnancies. Obstetrics and gynecology. 1997 Oct:90(4 Pt 1):524-8 [PubMed PMID: 9380309]
Sandlin AT, Ounpraseuth ST, Spencer HJ, Sick CL, Lang PM, Magann EF. Amniotic fluid volume in normal singleton pregnancies: modeling with quantile regression. Archives of gynecology and obstetrics. 2014 May:289(5):967-72. doi: 10.1007/s00404-013-3087-2. Epub 2013 Nov 17 [PubMed PMID: 24241077]
Shenker L, Reed KL, Anderson CF, Borjon NA. Significance of oligohydramnios complicating pregnancy. American journal of obstetrics and gynecology. 1991 Jun:164(6 Pt 1):1597-9; discussion 1599-600 [PubMed PMID: 2048607]
Shipp TD, Bromley B, Pauker S, Frigoletto FD Jr, Benacerraf BR. Outcome of singleton pregnancies with severe oligohydramnios in the second and third trimesters. Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. 1996 Feb:7(2):108-13 [PubMed PMID: 8776235]
Level 2 (mid-level) evidenceD'Ambrosio V, Vena F, Scopelliti A, D'Aniello D, Savastano G, Brunelli R, Giancotti A. Use of non-steroidal anti-inflammatory drugs in pregnancy and oligohydramnios: a review. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2023 Dec:36(2):2253956. doi: 10.1080/14767058.2023.2253956. Epub 2023 Sep 27 [PubMed PMID: 38092425]
Society for Maternal-Fetal Medicine (SMFM), Miller RS, Miller JL, Monson MA, Porter TF, Običan SG, Simpson LL, SMFM Publications Committee. Electronic address: pubs@smfm.org. Society for Maternal-Fetal Medicine Consult Series #72: Twin-twin transfusion syndrome and twin anemia-polycythemia sequence. American journal of obstetrics and gynecology. 2024 Oct:231(4):B16-B37. doi: 10.1016/j.ajog.2024.07.017. Epub 2024 Jul 18 [PubMed PMID: 39029545]
Wieacker P, Wilhelm C, Prömpeler H, Petersen KG, Schillinger H, Breckwoldt M. Pathophysiology of polyhydramnios in twin transfusion syndrome. Fetal diagnosis and therapy. 1992:7(2):87-92 [PubMed PMID: 1386987]
Level 3 (low-level) evidenceKontopoulos E, Chmait RH, Quintero RA. Twin-to-Twin Transfusion Syndrome: Definition, Staging, and Ultrasound Assessment. Twin research and human genetics : the official journal of the International Society for Twin Studies. 2016 Jun:19(3):175-83. doi: 10.1017/thg.2016.34. Epub [PubMed PMID: 27203605]
Brace RA, Anderson DF, Cheung CY. Fetal swallowing as a protective mechanism against oligohydramnios and polyhydramnios in late gestation sheep. Reproductive sciences (Thousand Oaks, Calif.). 2013 Mar:20(3):326-30. doi: 10.1177/1933719112453510. Epub 2012 Aug 7 [PubMed PMID: 22872543]
Kullama LK, Agnew CL, Day L, Ervin MG, Ross MG. Ovine fetal swallowing and renal responses to oligohydramnios. The American journal of physiology. 1994 Mar:266(3 Pt 2):R972-8 [PubMed PMID: 8160894]
Hou L, Wang X, Hellerstein S, Zou L, Ruan Y, Zhang W. Delivery mode and perinatal outcomes after diagnosis of oligohydramnios at term in China. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2020 Jul:33(14):2408-2414. doi: 10.1080/14767058.2018.1553944. Epub 2018 Dec 13 [PubMed PMID: 30486718]
Figueroa L, McClure EM, Swanson J, Nathan R, Garces AL, Moore JL, Krebs NF, Hambidge KM, Bauserman M, Lokangaka A, Tshefu A, Mirza W, Saleem S, Naqvi F, Carlo WA, Chomba E, Liechty EA, Esamai F, Swanson D, Bose CL, Goldenberg RL. Oligohydramnios: a prospective study of fetal, neonatal and maternal outcomes in low-middle income countries. Reproductive health. 2020 Jan 30:17(1):19. doi: 10.1186/s12978-020-0854-y. Epub 2020 Jan 30 [PubMed PMID: 32000798]
Kim BJ, Romero R, Mi Lee S, Park CW, Shin Park J, Jun JK, Yoon BH. Clinical significance of oligohydramnios in patients with preterm labor and intact membranes. Journal of perinatal medicine. 2011 Mar:39(2):131-6. doi: 10.1515/jpm.2010.168. Epub 2011 Jan 26 [PubMed PMID: 21265728]
Murzakanova G, Räisänen S, Jacobsen AF, Sole KB, Bjarkø L, Laine K. Adverse perinatal outcomes in 665,244 term and post-term deliveries-a Norwegian population-based study. European journal of obstetrics, gynecology, and reproductive biology. 2020 Apr:247():212-218. doi: 10.1016/j.ejogrb.2020.02.028. Epub 2020 Feb 17 [PubMed PMID: 32146227]
Twesigomwe G, Migisha R, Agaba DC, Owaraganise A, Aheisibwe H, Tibaijuka L, Abesiga L, Ngonzi J, Tornes YF. Prevalence and associated factors of oligohydramnios in pregnancies beyond 36 weeks of gestation at a tertiary hospital in southwestern Uganda. BMC pregnancy and childbirth. 2022 Aug 2:22(1):610. doi: 10.1186/s12884-022-04939-x. Epub 2022 Aug 2 [PubMed PMID: 35918640]
Reddy UM, Abuhamad AZ, Levine D, Saade GR, Fetal Imaging Workshop Invited Participants. Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2014 May:33(5):745-57. doi: 10.7863/ultra.33.5.745. Epub [PubMed PMID: 24764329]
Dildy GA 3rd, Lira N, Moise KJ Jr, Riddle GD, Deter RL. Amniotic fluid volume assessment: comparison of ultrasonographic estimates versus direct measurements with a dye-dilution technique in human pregnancy. American journal of obstetrics and gynecology. 1992 Oct:167(4 Pt 1):986-94 [PubMed PMID: 1415438]
Society for Maternal-Fetal Medicine (SMFM). Electronic address: pubs@smfm.org, Dashe JS, Pressman EK, Hibbard JU. SMFM Consult Series #46: Evaluation and management of polyhydramnios. American journal of obstetrics and gynecology. 2018 Oct:219(4):B2-B8. doi: 10.1016/j.ajog.2018.07.016. Epub 2018 Jul 23 [PubMed PMID: 30048635]
Committee on Practice Bulletins—Obstetrics and the American Institute of Ultrasound in Medicine. Practice Bulletin No. 175: Ultrasound in Pregnancy. Obstetrics and gynecology. 2016 Dec:128(6):e241-e256 [PubMed PMID: 27875472]
Hughes DS, Whittington JR, Kim H, Gunderman B, Ounpraseuth S, Magann EF. Is There a Difference in Sonographic Estimation of Amniotic Fluid Volume When Measuring With the Probe Perpendicular to the Floor Compared With Perpendicular to the Uterine Contour? Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC. 2019 Sep:41(9):1295-1301. doi: 10.1016/j.jogc.2019.01.017. Epub 2019 Mar 23 [PubMed PMID: 30910340]
Goldkrand JW, Hough TM, Lentz SU, Clements SP, Bryant JL, Hodges JA. Comparison of the amniotic fluid index with gray-scale and color Doppler ultrasound. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2003 May:13(5):318-22 [PubMed PMID: 12916682]
Zlatnik MG, Olson G, Bukowski R, Saade GR. Amniotic fluid index measured with the aid of color flow Doppler. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2003 Apr:13(4):242-5 [PubMed PMID: 12854924]
Odibo IN, Whittemore BS, Hughes DS, Simmons PM, Ounpraseuth ST, Magann EF. Addition of Color Doppler Sonography for Detection of Amniotic Fluid Disturbances and Its Implications on Perinatal Outcomes. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2017 Sep:36(9):1875-1881. doi: 10.1002/jum.14223. Epub 2017 May 15 [PubMed PMID: 28503847]
Magann EF, Chauhan SP, Barrilleaux PS, Whitworth NS, McCurley S, Martin JN. Ultrasound estimate of amniotic fluid volume: color Doppler overdiagnosis of oligohydramnios. Obstetrics and gynecology. 2001 Jul:98(1):71-4 [PubMed PMID: 11430959]
Hughes DS, Magann EF, Whittington JR, Wendel MP, Sandlin AT, Ounpraseuth ST. Accuracy of the Ultrasound Estimate of the Amniotic Fluid Volume (Amniotic Fluid Index and Single Deepest Pocket) to Identify Actual Low, Normal, and High Amniotic Fluid Volumes as Determined by Quantile Regression. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2020 Feb:39(2):373-378. doi: 10.1002/jum.15116. Epub 2019 Aug 18 [PubMed PMID: 31423632]
Magann EF, Sanderson M, Martin JN, Chauhan S. The amniotic fluid index, single deepest pocket, and two-diameter pocket in normal human pregnancy. American journal of obstetrics and gynecology. 2000 Jun:182(6):1581-8 [PubMed PMID: 10871481]
Kehl S, Schelkle A, Thomas A, Puhl A, Meqdad K, Tuschy B, Berlit S, Weiss C, Bayer C, Heimrich J, Dammer U, Raabe E, Winkler M, Faschingbauer F, Beckmann MW, Sütterlin M. Single deepest vertical pocket or amniotic fluid index as evaluation test for predicting adverse pregnancy outcome (SAFE trial): a multicenter, open-label, randomized controlled trial. Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. 2016 Jun:47(6):674-9. doi: 10.1002/uog.14924. Epub [PubMed PMID: 26094600]
Level 1 (high-level) evidenceNabhan AF, Abdelmoula YA. Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome. The Cochrane database of systematic reviews. 2008 Jul 16:2008(3):CD006593. doi: 10.1002/14651858.CD006593.pub2. Epub 2008 Jul 16 [PubMed PMID: 18646160]
Level 1 (high-level) evidenceSekhon S, Rosenbloom JI, Doering M, Conner SN, Macones GA, Colditz GA, Tuuli MG, Carter EB. Diagnostic utility of maximum vertical pocket versus amniotic fluid index in assessing amniotic fluid volume for the prediction of adverse maternal and fetal outcomes: a systematic review and meta-analysis. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2021 Nov:34(22):3730-3739. doi: 10.1080/14767058.2019.1691988. Epub 2019 Nov 20 [PubMed PMID: 31709861]
Level 1 (high-level) evidenceBicocca MJ, Qureshey EJ, Chauhan SP, Hernandez-Andrade E, Sibai BM, Nowlen C, Stafford I. Semiquantitative Assessment of Amniotic Fluid Among Individuals With and Without Diabetes Mellitus. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2022 Feb:41(2):447-455. doi: 10.1002/jum.15725. Epub 2021 Apr 22 [PubMed PMID: 33885190]
Dayal S, Jenkins SM, Hong PL. Preterm and Term Prelabor Rupture of Membranes (PPROM and PROM). StatPearls. 2025 Jan:(): [PubMed PMID: 30422483]
Vora NL, Norton ME. Prenatal exome and genome sequencing for fetal structural abnormalities. American journal of obstetrics and gynecology. 2023 Feb:228(2):140-149. doi: 10.1016/j.ajog.2022.08.040. Epub 2022 Aug 24 [PubMed PMID: 36027950]
Singer A, Maya I, Sukenik-Halevy R, Tenne T, Lev D, Ben Shachar S, Sagi-Dain L. Microarray findings in pregnancies with oligohydramnios - a retrospective cohort study and literature review. Journal of perinatal medicine. 2019 Dec 18:48(1):53-58. doi: 10.1515/jpm-2019-0228. Epub [PubMed PMID: 31811807]
Level 2 (mid-level) evidenceShi X, Ding H, Li C, Liu L, Yu L, Zhu J, Wu J. Clinical utility of chromosomal microarray analysis and whole exome sequencing in foetuses with oligohydramnios. Annals of medicine. 2023 Dec:55(1):2215539. doi: 10.1080/07853890.2023.2215539. Epub [PubMed PMID: 37243546]
Monaghan KG, Leach NT, Pekarek D, Prasad P, Rose NC, ACMG Professional Practice and Guidelines Committee. The use of fetal exome sequencing in prenatal diagnosis: a points to consider document of the American College of Medical Genetics and Genomics (ACMG). Genetics in medicine : official journal of the American College of Medical Genetics. 2020 Apr:22(4):675-680. doi: 10.1038/s41436-019-0731-7. Epub 2020 Jan 8 [PubMed PMID: 31911674]
. Indications for Outpatient Antenatal Fetal Surveillance: ACOG Committee Opinion, Number 828. Obstetrics and gynecology. 2021 Jun 1:137(6):e177-e197. doi: 10.1097/AOG.0000000000004407. Epub [PubMed PMID: 34011892]
Level 3 (low-level) evidenceSociety for Maternal-Fetal Medicine (SMFM). Electronic address: pubs@smfm.org, Martins JG, Biggio JR, Abuhamad A. Society for Maternal-Fetal Medicine Consult Series #52: Diagnosis and management of fetal growth restriction: (Replaces Clinical Guideline Number 3, April 2012). American journal of obstetrics and gynecology. 2020 Oct:223(4):B2-B17. doi: 10.1016/j.ajog.2020.05.010. Epub 2020 May 12 [PubMed PMID: 32407785]
. Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229. Obstetrics and gynecology. 2021 Jun 1:137(6):e116-e127. doi: 10.1097/AOG.0000000000004410. Epub [PubMed PMID: 34011889]
Doi S, Osada H, Seki K, Sekiya S. Effect of maternal hydration on oligohydramnios: a comparison of three volume expansion methods. Obstetrics and gynecology. 1998 Oct:92(4 Pt 1):525-9 [PubMed PMID: 9764623]
Deka D, Malhotra B. Role of maternal oral hydration in increasing amniotic fluid volume in pregnant women with oligohydramnios. International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics. 2001 May:73(2):155-6 [PubMed PMID: 11336736]
Burgos J, Quintana E, Cobos P, Osuna C, Centeno Mdel M, Melchor JC. Effect of maternal intravenous fluid therapy on external cephalic version at term: a prospective cohort study. American journal of obstetrics and gynecology. 2014 Dec:211(6):665.e1-7. doi: 10.1016/j.ajog.2014.06.031. Epub 2014 Jun 17 [PubMed PMID: 24949536]
Azarkish F, Janghorban R, Bozorgzadeh S, Arzani A, Balouchi R, Didehvar M. The effect of maternal intravenous hydration on amniotic fluid index in oligohydramnios. BMC research notes. 2022 Mar 7:15(1):95. doi: 10.1186/s13104-022-05985-6. Epub 2022 Mar 7 [PubMed PMID: 35255952]
Gizzo S, Noventa M, Vitagliano A, Dall'Asta A, D'Antona D, Aldrich CJ, Quaranta M, Frusca T, Patrelli TS. An Update on Maternal Hydration Strategies for Amniotic Fluid Improvement in Isolated Oligohydramnios and Normohydramnios: Evidence from a Systematic Review of Literature and Meta-Analysis. PloS one. 2015:10(12):e0144334. doi: 10.1371/journal.pone.0144334. Epub 2015 Dec 11 [PubMed PMID: 26658482]
Level 1 (high-level) evidenceMalhotra B, Deka D. Duration of the increase in amniotic fluid index (AFI) after acute maternal hydration. Archives of gynecology and obstetrics. 2004 Mar:269(3):173-5 [PubMed PMID: 14576952]
Ghafarnejad M, Tehrani MB, Anaraki FB, Mood NI, Nasehi L. Oral hydration therapy in oligohydramnios. The journal of obstetrics and gynaecology research. 2009 Oct:35(5):895-900. doi: 10.1111/j.1447-0756.2009.01043.x. Epub [PubMed PMID: 20149038]
Fait G, Pauzner D, Gull I, Lessing JB, Jaffa AJ, Wolman I. Effect of 1 week of oral hydration on the amniotic fluid index. The Journal of reproductive medicine. 2003 Mar:48(3):187-90 [PubMed PMID: 12698777]
Patrelli TS, Gizzo S, Cosmi E, Carpano MG, Di Gangi S, Pedrazzi G, Piantelli G, Modena AB. Maternal hydration therapy improves the quantity of amniotic fluid and the pregnancy outcome in third-trimester isolated oligohydramnios: a controlled randomized institutional trial. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2012 Feb:31(2):239-44 [PubMed PMID: 22298867]
Level 1 (high-level) evidenceAnant M, Murmu S, Priya S. A Randomized Trial of Inpatient and Home-Based Maternal Oral Hydration Therapy in Isolated Oligohydramnios and Its Effect on Amniotic Fluid Index and Perinatal Outcome. Cureus. 2023 Jul:15(7):e41326. doi: 10.7759/cureus.41326. Epub 2023 Jul 3 [PubMed PMID: 37539407]
Level 1 (high-level) evidenceMustafa HJ, Khalil A, Johnson S, Gordijn SJ, Ganzevoort W, Melling C, Koh CJ, Mandy GT, Kilby MD, Johnson A, Quintero RA, Ryan G, Shamshirsaz AA, Nassr AA, on behalf of the LUTO Working Group. Fetal lower urinary tract obstruction: international Delphi consensus on management and core outcome set. Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology. 2024 Nov:64(5):635-650. doi: 10.1002/uog.27684. Epub [PubMed PMID: 38748971]
Level 3 (low-level) evidenceCelik E, Yildiz AB, Guler Cekic S, Unal C, Ayhan I, Melekoglu R, Gursoy T. Amnioinfusion vs. standard management for the second trimester PPROM: a systematic review and meta-analysis of observational studies and RCTs. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2023 Dec:36(2):2230511. doi: 10.1080/14767058.2023.2230511. Epub [PubMed PMID: 37408113]
Level 1 (high-level) evidenceAmerican College of Obstetricians and Gynecologists’ Committee on Obstetric Practice, Society for Maternal-Fetal Medicine. Medically Indicated Late-Preterm and Early-Term Deliveries: ACOG Committee Opinion, Number 831. Obstetrics and gynecology. 2021 Jul 1:138(1):e35-e39. doi: 10.1097/AOG.0000000000004447. Epub [PubMed PMID: 34259491]
Level 3 (low-level) evidenceRhoades JS, Stout MJ, Macones GA, Cahill AG. Effect of Oligohydramnios on Fetal Heart Rate Patterns during Term Labor Induction. American journal of perinatology. 2019 Jun:36(7):715-722. doi: 10.1055/s-0038-1675152. Epub 2018 Oct 29 [PubMed PMID: 30372774]
Pitt C, Sanchez-Ramos L, Kaunitz AM, Gaudier F. Prophylactic amnioinfusion for intrapartum oligohydramnios: a meta-analysis of randomized controlled trials. Obstetrics and gynecology. 2000 Nov:96(5 Pt 2):861-6 [PubMed PMID: 11094242]
Level 1 (high-level) evidencePeipert JF, Donnenfeld AE. Oligohydramnios: a review. Obstetrical & gynecological survey. 1991 Jun:46(6):325-39 [PubMed PMID: 2067755]
Level 2 (mid-level) evidenceMehler K, Gottschalk I, Burgmaier K, Volland R, Büscher AK, Feldkötter M, Keller T, Weber LT, Kribs A, Habbig S. Prenatal parental decision-making and postnatal outcome in renal oligohydramnios. Pediatric nephrology (Berlin, Germany). 2018 Apr:33(4):651-659. doi: 10.1007/s00467-017-3812-3. Epub 2017 Oct 27 [PubMed PMID: 29075889]
Chauhan SP, Taylor M, Shields D, Parker D, Scardo JA, Magann EF. Intrauterine growth restriction and oligohydramnios among high-risk patients. American journal of perinatology. 2007 Apr:24(4):215-21 [PubMed PMID: 17447191]
Nishi K, Ozawa K, Kamei K, Sato M, Ogura M, Muromoto J, Sugibayashi R, Isayama T, Ito Y, Wada S, Yokoo T, Ishikura K. Long-Term Outcomes, Including Fetal and Neonatal Prognosis, of Renal Oligohydramnios: A Retrospective Study over 22 Years. The Journal of pediatrics. 2024 Oct:273():114151. doi: 10.1016/j.jpeds.2024.114151. Epub 2024 Jun 15 [PubMed PMID: 38880380]
Level 2 (mid-level) evidenceHofmeyr GJ, Gülmezoglu AM. Maternal hydration for increasing amniotic fluid volume in oligohydramnios and normal amniotic fluid volume. The Cochrane database of systematic reviews. 2002:(1):CD000134 [PubMed PMID: 11869566]
Level 1 (high-level) evidenceYamada Y, Zhang X, Henderson MET, Sagayama H, Pontzer H, Watanabe D, Yoshida T, Kimura M, Ainslie PN, Andersen LF, Anderson LJ, Arab L, Baddou I, Bedu-Addo K, Blaak EE, Blanc S, Bonomi AG, Bouten CVC, Bovet P, Buchowski MS, Butte NF, Camps SG, Close GL, Cooper JA, Cooper R, Das SK, Dugas LR, Eaton S, Ekelund U, Entringer S, Forrester T, Fudge BW, Goris AH, Gurven M, Halsey LG, Hambly C, El Hamdouchi A, Hoos MB, Hu S, Joonas N, Joosen AM, Katzmarzyk P, Kempen KP, Kraus WE, Kriengsinyos W, Kushner RF, Lambert EV, Leonard WR, Lessan N, Martin CK, Medin AC, Meijer EP, Morehen JC, Morton JP, Neuhouser ML, Nicklas TA, Ojiambo RM, Pietiläinen KH, Pitsiladis YP, Plange-Rhule J, Plasqui G, Prentice RL, Rabinovich RA, Racette SB, Raichlen DA, Ravussin E, Redman LM, Reilly JJ, Reynolds RM, Roberts SB, Schuit AJ, Sardinha LB, Silva AM, Sjödin AM, Stice E, Urlacher SS, Valenti G, Van Etten LM, Van Mil EA, Wells JCK, Wilson G, Wood BM, Yanovski JA, Murphy-Alford AJ, Loechl CU, Luke AH, Rood J, Westerterp KR, Wong WW, Miyachi M, Schoeller DA, Speakman JR, International Atomic Energy Agency (IAEA) Doubly Labeled Water (DLW) Database Consortium§. Variation in human water turnover associated with environmental and lifestyle factors. Science (New York, N.Y.). 2022 Nov 25:378(6622):909-915. doi: 10.1126/science.abm8668. Epub 2022 Nov 24 [PubMed PMID: 36423296]