From the Guidelines
Oligohydramnios and polyhydramnios present with distinct key symptoms that help identify abnormal amniotic fluid volumes during pregnancy, including a uterus that appears small or large for gestational age, difficulty palpating fetal parts, reduced fetal movement, and abnormal fetal heart rate patterns, which can be diagnosed through ultrasound measurement of amniotic fluid index or maximum vertical pocket 1.
Key Symptoms of Oligohydramnios
- A uterus that appears small for gestational age
- Difficulty palpating fetal parts due to compression
- Reduced fetal movement reported by the mother
- Abnormal fetal heart rate patterns
- Leaking fluid if there's premature rupture of membranes
Key Symptoms of Polyhydramnios
- A uterus that appears large for gestational age
- Maternal discomfort including shortness of breath, abdominal pain, and swelling in the lower extremities
- Difficulty walking
- Premature contractions
- Increased risk of premature labor These symptoms are associated with adverse fetal outcomes, including stillbirth and perinatal mortality, as reported in a large retrospective study of 228,239 singleton births, where oligohydramnios was found to be an independent risk factor for stillbirth (odds ratio [OR], 2.6; 95% confidence interval [CI], 2.1-3.2; P < .001) 1. Similarly, polyhydramnios was found to be an independent risk factor for perinatal mortality (OR, 5.8; 95% CI, 3.68-9.11) 1.
Diagnosis and Management
Diagnosis of oligohydramnios and polyhydramnios is typically made through ultrasound measurement of amniotic fluid index or maximum vertical pocket, with oligohydramnios defined as an MVP < 2 cm or AFI < 5 cm, and polyhydramnios defined as an MVP > 8 cm or an AFI > 25 cm or >95th percentile for gestational age 1. Management of these conditions involves close monitoring of fetal well-being and maternal health, with potential interventions including induction of labor or cesarean delivery, depending on the severity of the condition and the presence of underlying fetal or maternal complications.
From the Research
Key Symptoms of Oligohydramnios and Polyhydramnios
- Oligohydramnios (low amniotic fluid) is associated with adverse maternal and neonatal outcomes, including:
- Cesarean delivery
- Operative vaginal delivery
- Induction of labor
- Postpartum hemorrhage
- Small for gestational age neonate
- Intrauterine demise
- Neonatal death
- NICU admission
- APGAR less than 7 at 5 minutes of life 2
- Polyhydramnios (excess amniotic fluid) is associated with adverse outcomes, including:
- Cesarean delivery
- Induction of labor
- Placental abruption
- Shoulder dystocia
- Cord prolapse
- Postpartum hemorrhage
- Intrauterine fetal demise
- NICU admission
- Neonatal death
- APGAR less than 7 at 5 minutes of life
- Large for gestational age neonate
- Respiratory distress syndrome 2
- Typical symptoms of polyhydramnios include:
- Maternal dyspnea
- Preterm labor
- Premature rupture of membranes (PPROM)
- Abnormal fetal presentation
- Cord prolapse
- Postpartum hemorrhage 3
Causes and Diagnosis
- Polyhydramnios is defined as a pathological increase of amniotic fluid volume in pregnancy and is associated with increased perinatal morbidity and mortality 3
- Common causes of polyhydramnios include:
- Gestational diabetes
- Fetal anomalies with disturbed fetal swallowing of amniotic fluid
- Fetal infections
- Other, rarer causes 3
- The diagnosis of polyhydramnios is obtained by ultrasound 3
- Oligohydramnios has been implemented as a sign of potential fetal compromise and associated with an increased incidence of adverse perinatal morbidity and mortality 4