Chorioamnionitis, first trimester, fetus 3

This code signifies an inflammatory condition of the fetal membranes (amnion and chorion) and amniotic fluid, occurring during the first trimester of pregnancy, specifically affecting the third fetus in a multiple gestation. It indicates an intrauterine infection that can lead to premature rupture of membranes, preterm labor, and fetal complications.

Assign this code when documentation clearly indicates a diagnosis of chorioamnionitis in a pregnancy that is definitively in its first trimester, and the infection is attributed to the third fetus in a multifetal pregnancy. Supporting documentation would include physician notes detailing the diagnosis, gestational age, and the specific fetus affected in a multiple gestation.

• Ensure the gestational age is explicitly documented as "first trimester" to avoid miscoding with chorioamnionitis in other trimesters.
• Verify that the documentation specifies "fetus 3" in cases of multiple gestations; otherwise, use the unspecified fetus code.
• Always sequence this code after the primary obstetric code indicating the pregnancy itself.