Polyhydramnios, first trimester, fetus 1

This code signifies an excessive accumulation of amniotic fluid surrounding the first fetus during the initial trimester of pregnancy. Polyhydramnios can indicate underlying fetal anomalies, maternal conditions, or placental issues, and requires careful monitoring.

Apply this code when documentation explicitly states polyhydramnios is present in the first trimester for the first fetus. This diagnosis is typically made via ultrasound measurement of the amniotic fluid index (AFI) or deepest vertical pocket (DVP).

• Ensure documentation specifies "first trimester" and "fetus 1" to accurately assign this code.
• Distinguish from polyhydramnios occurring in later trimesters (O40.2XX1, O40.3XX1) or affecting other fetuses in a multiple gestation.
• Always code any associated fetal anomalies or maternal conditions contributing to the polyhydramnios.