What should you know about low amniotic fluid in the second trimester?

The second trimester is a period when the baby is growing and the amount of fluid is assessed during ultrasound. Low fluid may reflect leaking membranes, placental concerns, reduced fetal urine production or an ultrasound measurement that needs confirmation. It may not cause a noticeable sensation, so a scan finding should be discussed with the maternity team even when you feel well.

Assessment usually considers the baby’s anatomy and growth, placenta, blood flow, fluid measurement and whether there are signs of infection or membrane rupture. A growth scan can help bring these findings together. The outlook and follow-up cannot be judged from the fluid measurement without this wider information.

Contact your maternity team and attend the recommended assessment rather than waiting for a routine appointment. Tell them about watery discharge, bleeding, pain, fever, contractions, urinary symptoms or changes in fetal movement. Keep a record of instructions and appointments, and take medicines only as prescribed.

Your team may repeat ultrasound, assess growth and blood flow, check for fluid leakage or recommend specialist review. Normal hydration is sensible unless your clinician says otherwise, but drinking extra fluid cannot replace investigation. Birth planning is individual; induction of labour is not an automatic response to a second-trimester measurement.

Seek urgent maternity advice for a gush or persistent trickle of fluid, vaginal bleeding, regular contractions, fever, worsening abdominal pain or reduced fetal movements. Emergency help is needed for severe pain, heavy bleeding, fainting or feeling very unwell. Early assessment can identify membrane or infection concerns that should not wait for a scheduled scan.

Ask how low the measurement is, whether it was confirmed, and whether the membranes, placenta, anatomy, growth and blood flow look reassuring. Ask when the next scan is due, which symptoms require immediate contact, whether you need specialist review, and which findings would change monitoring or later birth planning.