O41.12 Chorioamnionitis

Name of the Condition

• Chorioamnionitis (ICD Code: O41.12)

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 based on clinical evaluation of maternal symptoms, laboratory testing for infection markers (e.g., elevated C-reactive protein or white blood cell count), and ultrasound to assess fetal well-being. Amniotic fluid culture or placental examination may confirm the infection.

Treatment Options

Treatment typically 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.

Prognosis and Follow-Up

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

Complications

• Preterm labor or delivery
• Fetal distress or sepsis
• Maternal sepsis or postpartum infections
• Long-term neurodevelopmental issues in the infant

Lifestyle & Prevention

• Attend regular prenatal care to detect and manage infections early.
• Avoid unnecessary vaginal examinations during pregnancy.
• Practice good hygiene to reduce infection risk.
• Seek prompt care for symptoms like fever or unusual discharge.

When to Seek Professional Help

Contact a healthcare provider immediately if experiencing fever, uterine tenderness, or foul-smelling vaginal discharge during pregnancy. These symptoms may indicate chorioamnionitis and require urgent evaluation.

Tips for Medical Coders

Document the clinical findings supporting the diagnosis, including maternal fever, fetal tachycardia, or uterine tenderness. Ensure the code is assigned based on confirmed infection of the amniotic sac and membranes. Note any trimester or severity details if available, though O41.12 is specific to chorioamnionitis without further specification.