O41.1233 Chorioamnionitis, third trimester, fetus 3

Name of the Condition

• Chorioamnionitis, Third Trimester, Fetus 3 (ICD Code: O41.1233)

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.

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

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)

Diagnosis

Diagnosis is typically based on clinical criteria, including maternal fever, maternal or fetal tachycardia, uterine tenderness, and foul-smelling amniotic fluid. Laboratory tests may include blood cultures, amniotic fluid cultures, or inflammatory markers. Imaging or fetal monitoring may be used to assess fetal well-being.

Treatment Options

Treatment usually involves intravenous antibiotics to target common pathogens. Delivery may be expedited if the infection is severe or if the fetus is at risk. Supportive care, such as hydration and monitoring, is also provided. The choice of antibiotics depends on local resistance patterns and clinical severity.

Prognosis and Follow-Up

With prompt treatment, outcomes for both mother and fetus can be favorable. However, untreated or severe cases may lead to complications. Follow-up care includes monitoring for infection recurrence and assessing fetal development. Long-term follow-up may be necessary for infants exposed to infection.

Complications

• Preterm birth
• Neonatal sepsis or pneumonia
• Maternal postpartum infection
• Fetal distress or stillbirth
• Chronic lung disease in the newborn

Lifestyle & Prevention

• Attend regular prenatal care to monitor for infections
• Avoid unnecessary vaginal examinations during pregnancy
• Treat underlying infections promptly (e.g., urinary tract infections)
• Follow guidelines for membrane rupture management

When to Seek Professional Help

Seek immediate medical attention if experiencing fever, abdominal pain, or reduced fetal movement during pregnancy. Prompt evaluation is critical to prevent complications.

Tips for Medical Coders

This code specifies chorioamnionitis in the third trimester with a focus on the fetus (fetus 3). Ensure documentation supports the trimester and fetal involvement. Code O41.1233 is distinct from other chorioamnionitis codes due to the fetal specification. Verify that clinical details align with the code's description to ensure accurate assignment.