O41.1239 Chorioamnionitis, third trimester, other fetus

Name of the Condition

• Chorioamnionitis, Third Trimester, Other Fetus (ICD Code: O41.1239)

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 maternal blood cultures, amniotic fluid analysis, or fetal monitoring. Imaging or ultrasound may be used to assess fetal well-being or detect complications.

Treatment Options

Treatment usually involves intravenous antibiotics to target common pathogens. Delivery may be recommended 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 improve, though complications may still occur. Follow-up care includes monitoring for infection recurrence, assessing fetal health, and addressing any long-term effects. Maternal recovery is generally good with appropriate care.

Complications

• Preterm birth
• Neonatal sepsis or pneumonia
• Maternal postpartum infections
• Fetal distress or stillbirth
• Long-term neurological issues in the infant

Lifestyle & Prevention

• Attend regular prenatal care to detect and manage infections early.
• Avoid unnecessary vaginal examinations during pregnancy.
• Seek prompt treatment for urinary tract or other infections.
• Follow guidelines for membrane rupture management.

When to Seek Professional Help

Contact a healthcare provider if you experience fever, abdominal pain, foul-smelling vaginal discharge, or reduced fetal movement during pregnancy. Immediate care is needed if symptoms worsen or if you have a history of chorioamnionitis.

Tips for Medical Coders

Document the specific fetus affected (e.g., "other fetus") and any relevant clinical details to support the use of O41.1239. Ensure documentation aligns with the clinical scenario and coding guidelines for chorioamnionitis in the third trimester.