O41.1232 Chorioamnionitis, third trimester, fetus 2

Name of the Condition

• Chorioamnionitis, Third Trimester, Fetus 2 (ICD Code: O41.1232)

Summary

Chorioamnionitis is an infection of the fetal membranes (chorion and amnion) and amniotic fluid during pregnancy. This condition involves microbial invasion, typically bacterial, and can affect both maternal and fetal health. It is often associated with inflammation and may lead to complications if not managed promptly. The infection can occur at any stage of pregnancy but is more common in the second or third trimester. This specific code applies when the condition is present in the third trimester and involves a multifetal pregnancy with the second fetus affected.

Causes

The infection usually results from bacteria ascending from the vaginal tract into the uterus, though hematogenous spread (via the bloodstream) or direct contamination can also occur. Common pathogens include group B streptococcus, Escherichia coli, and other vaginal flora. Risk increases with prolonged rupture of membranes or invasive procedures during pregnancy.

Risk Factors

• Prolonged rupture of membranes (especially >18 hours)
• Multiple vaginal examinations during labor
• Preterm labor or delivery
• Maternal infections (e.g., urinary tract infections)
• Low socioeconomic status or limited prenatal care
• History of prior intrauterine infections
• Multifetal pregnancy (e.g., twins, triplets)

Symptoms

• Maternal fever (≥38°C or 100.4°F)
• Maternal tachycardia (≥100 beats per minute)
• Fetal tachycardia (≥160 beats per minute)
• Uterine tenderness
• Foul-smelling amniotic fluid (if membranes are ruptured)
• Maternal leukocytosis (elevated white blood cell count)

Diagnosis

Diagnosis relies on clinical evaluation of maternal symptoms, laboratory testing for infection markers (e.g., elevated white blood cell count), and ultrasound to assess amniotic fluid and fetal status. Amniocentesis may be used for culture if membranes are ruptured. In multifetal pregnancies, additional monitoring may be required to assess each fetus individually.

Treatment Options

Treatment typically involves intravenous antibiotics to target common pathogens, such as ampicillin and gentamicin. Delivery may be expedited if the pregnancy is at or near term, or if maternal or fetal status deteriorates. Supportive care, including hydration and monitoring, is also provided.

Prognosis and Follow-Up

With prompt treatment, outcomes for both mother and fetus can be favorable. However, untreated or severe cases may lead to preterm birth, neonatal sepsis, or other complications. Follow-up care includes monitoring for infection recurrence and assessing fetal development.

Complications

• Preterm labor or delivery
• Neonatal sepsis or pneumonia
• Maternal postpartum infection
• Chorioamnionitis in the second fetus (in multifetal pregnancies)
• Long-term developmental issues for the affected fetus

Lifestyle & Prevention

• Attend regular prenatal check-ups to monitor for infections.
• Practice good hygiene, especially during vaginal exams or procedures.
• Report any symptoms like fever or foul-smelling discharge promptly.
• Avoid unnecessary invasive procedures during pregnancy.

When to Seek Professional Help

Seek immediate medical attention if you experience fever, uterine tenderness, or changes in fetal movement, especially if you have a history of prolonged membrane rupture or multifetal pregnancy.

Tips for Medical Coders

When coding O41.1232, ensure documentation specifies the third trimester and identifies the second fetus in a multifetal pregnancy. Verify that the infection is confirmed clinically or via laboratory testing, and that the trimester and fetal number are clearly documented. This code is specific to the third trimester and the second fetus; do not use it for other trimesters or fetuses without appropriate documentation.