What should you know about causes of polyhydramnios in pregnancy?

Maternal diabetes or raised blood glucose, fetal digestive or neurological conditions, fetal anaemia, certain infections, and an imbalance of blood flow between babies in a shared-placenta twin pregnancy are possible causes. Sometimes the pregnancy otherwise appears healthy and no explanation is identified.

Amniotic fluid cushions the baby and allows movement. Too much fluid stretches the womb more than expected and may cause abdominal pressure, reflux, swelling, or breathlessness. It can also make the baby’s position less stable.

Polyhydramnios describes an ultrasound finding, not a single disease. Its significance depends on how much fluid is present, how quickly it appeared, the pregnancy stage, whether one baby or more is present, and what the scan shows about growth and anatomy.

Keep all antenatal and scan appointments, and learn how to contact your maternity triage unit. Your team may check blood glucose, review fetal anatomy and movement, assess placental and fetal blood flow, and repeat fluid measurements. Further blood tests depend on your history and scan findings.

A growth scan helps the team compare fetal size and fluid with earlier findings. Depending on symptoms and severity, care may range from observation to treatment of a contributing condition or specialist procedures. Do not restrict drinks unless your maternity clinician gives a separate medical reason.

Call immediately if fetal movements are reduced or altered, your waters may have broken, bleeding occurs, contractions become regular or painful, or the abdomen becomes suddenly larger and tense. Marked breathlessness, severe pain, collapse, or heavy bleeding requires emergency help.

After the waters break, avoid walking around while seeking advice if you feel or see something in the vagina. Call emergency services, because rarely the umbilical cord can slip below the baby and needs immediate assessment.

Ask whether the excess fluid is mild, moderate, or severe; whether it developed gradually; and which cause is being considered. Discuss how often movement, growth, and fluid will be checked, whether fetal position affects delivery planning, and what to do if labour or waters breaking begins at home.