What do oligohydramnios and polyhydramnios refer to, and why are they clinically relevant?

• A. Oligohydramnios is low amniotic fluid; polyhydramnios is excessive amniotic fluid.
• B. Oligohydramnios and polyhydramnios both indicate placental location.
• C. They are terms for fetal lung development stages.
• D. They are not related to pregnancy outcomes.

Answer: (A)

Oligohydramnios and polyhydramnios refer to abnormal amounts of amniotic fluid surrounding the fetus. The volume of this fluid is normally balanced by fetal urine production, swallowing, and membrane exchanges, so deviations signal problems with fetal or placental function. Oligohydramnios means there is too little amniotic fluid, which can result from rupture of membranes, placental insufficiency, fetal kidney issues, or certain medications; it is clinically important because too little fluid can impair fetal movement, cord circulation, and lung development (pulmonary hypoplasia), and it can complicate labor. Polyhydramnios means there is too much fluid, which can occur with maternal diabetes, fetal swallowing problems (like esophageal or duodenal atresia), anencephaly, multiple gestations, or fetal hydrops; it raises risks such as preterm labor, malpresentation, placental abruption, and maternal discomfort. These conditions are assessed with ultrasound measurements of amniotic fluid volume (for example, the amniotic fluid index or single deepest pocket) to guide monitoring and delivery planning. The other options don’t describe fluid amount or its clinical implications, so they don’t fit the concept.