What should I do if I have polyhydramnios at seven months of pregnancy?

At 28 weeks’ gestation—commonly referred to as “seven months” of pregnancy—polyhydramnios (excess amniotic fluid) is diagnosed when the amniotic fluid index (AFI) exceeds 24 cm or the single deepest vertical pocket (SDVP) measures greater than 8 cm on ultrasound. While mild polyhydramnios is often idiopathic and may remain stable or resolve spontaneously, moderate to severe cases warrant thorough evaluation to identify underlying causes.

First-line assessment includes a detailed fetal anatomical ultrasound to screen for structural anomalies—particularly those affecting fetal swallowing (e.g., esophageal atresia, duodenal atresia) or central nervous system function (e.g., anencephaly), as well as signs of fetal infection (e.g., cytomegalovirus) or genetic syndromes. Maternal conditions such as gestational diabetes mellitus must be ruled out with a glucose challenge test or formal oral glucose tolerance test, since hyperglycemia can increase fetal urine output and contribute to fluid accumulation.

Management depends on severity and etiology. Asymptomatic mild polyhydramnios typically requires only increased surveillance: serial ultrasounds every 2–4 weeks to monitor fluid volume, fetal growth, and Doppler flow studies; maternal symptom assessment (e.g., dyspnea, abdominal discomfort, preterm contractions); and antenatal testing (e.g., non-stress tests or biophysical profiles) starting at 32 weeks if indicated. For symptomatic or severe cases, therapeutic amnioreduction may be considered to relieve maternal discomfort or reduce preterm labor risk—but this carries procedural risks including preterm rupture of membranes, placental abruption, and chorioamnionitis, and should only be performed in a tertiary center with immediate delivery capability.

It’s important to emphasize that most pregnancies with mild polyhydramnios progress uneventfully to term with favorable outcomes. However, close collaboration with a maternal-fetal medicine specialist is recommended to tailor monitoring and intervention based on individual risk factors, fetal findings, and maternal clinical status.