Rare diseases · Sign or symptom

Oligohydramnios

Low levels of amniotic fluid

HP:0001562

What it means

Diminished amniotic fluid volume in pregnancy.

Oligohydramnios is the opposite of polyhydramnios. In normal pregnancy the amniotic fluid volume increases by about 10 ml/day until the 34th, after which it slowly diminishes. A normal amniotic fluid volume at term is about 500-2,000 ml. Oligohydramnios is defined as an AFI (amniotic fluid index) less than 5 cm or smallest vertical pocket of fluid less than 2 cm.

Rare diseases that can present with this82

Always100%

1

Common30–79%

24

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Decreased amniotic fluid index · Maternal oligohydramnios

Oligohydramnios

Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.

Start free with Eleplan

This page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.