A 28-year-old unvaccinated woman presents to the antenatal clinic at 12 weeks gestation with fever, maculopapular rash, and arthralgia for 3 days. She has no history of rubella vaccination. Serological testing confirms acute rubella infection. What is the most appropriate immediate next step in management?

Explanation

## Clinical Context Rubella infection in the first trimester carries a **90% risk of congenital rubella syndrome (CRS)**, including cardiac defects, cataracts, deafness, and intellectual disability. Counselling and informed choice regarding pregnancy continuation is the standard of care. ## Management of Rubella in Pregnancy **Key Point:** There is no effective antiviral treatment for rubella. The focus shifts entirely to counselling and reproductive choice. **High-Yield:** Rubella vaccine (live attenuated) is contraindicated in pregnancy and should NOT be given. It is a teratogenic live vaccine. **Clinical Pearl:** The risk of CRS is highest in the first 8–12 weeks (>90%), declining to ~20% by 16 weeks and <1% after 20 weeks. ## Appropriate Next Steps | Step | Rationale | |------|----------| | **Counselling on CRS risk** | Essential; allows informed decision-making | | **Offer termination** | Legally and ethically appropriate in first trimester | | **Detailed fetal ultrasound** | If pregnancy continues; look for cardiac lesions, growth restriction | | **Amniocentesis at 18+ weeks** | If continuing; PCR for fetal infection (not before 18 weeks due to low sensitivity) | **Warning:** Do NOT give MMR vaccine in pregnancy — it is a live attenuated vaccine and is teratogenic. **Tip:** The question asks for the **immediate** next step. Counselling and informed choice precede all investigations and monitoring. ## Congenital Rubella Syndrome Triad - **Cardiac:** PDA, peripheral pulmonary stenosis - **Ocular:** Cataracts, glaucoma, retinopathy - **Auditory:** Sensorineural hearing loss (most common single defect) [cite:Park 26e Ch 25]