Causes of oligohydramnios

After fetal kidneys begin producing urine, that urine makes up much of the fluid. A condition affecting kidney development, urine production or urine flow can therefore lower the amount. Fluid may also fall when the placenta is not supporting the pregnancy adequately or when pregnancy continues beyond the expected time.

Low fluid is an ultrasound finding rather than a complete diagnosis. Its significance depends on when it appears, how low the measurement is, fetal growth, blood flow through the placenta and whether the membranes have ruptured.

Your team may repeat ultrasound measurements because fluid pockets can be difficult to measure consistently. They may also assess fetal growth, movement and wellbeing, examine for fluid leakage, review blood pressure and ask about medicines or health conditions that can affect placental function.

Keep every recommended monitoring appointment and follow the maternity unit's instructions for tracking fetal movement. Drink normally and avoid starting or stopping medicines without discussing them with your obstetric team. Extra drinking may help when dehydration contributes, but it does not correct every cause.

Care is individualised. It can include follow-up scans, closer fetal monitoring, assessment for ruptured membranes and planning the safest timing of birth. The gestational stage and the results of wellbeing checks guide whether continued observation or delivery is appropriate.

Contact your maternity unit immediately if your baby's movements are reduced or different from their usual pattern, or if you notice a gush or ongoing trickle of watery fluid. Do not wait for the next appointment to report either change.

Urgent assessment is also needed for vaginal bleeding, regular painful contractions, severe abdominal pain, fever, a severe headache, visual disturbance or sudden swelling. These symptoms can signal pregnancy complications that require prompt checks.

Ask how the fluid was measured, whether fetal growth and placental blood flow look reassuring, and whether membrane rupture has been excluded. Clarify the monitoring schedule, whom to call after hours and which findings might change the planned timing of birth.