A 28-year-old woman on warfarin conceives while taking the drug. Counselling about fetal risk should include which specific malformation associated with first-trimester exposure?

• A Neural tube defect
• B Nasal hypoplasia and stippled epiphyses ✓
• C Transposition of great arteries
• D Holoprosencephaly

Explanation

First-trimester warfarin exposure causes warfarin embryopathy: nasal hypoplasia, stippled vertebral and femoral epiphyses, and limb shortening, due to impaired bone morphogenesis from defective vitamin K dependent proteins. Exposure later in pregnancy causes CNS abnormalities and fetal haemorrhage. Neural tube defects are classically linked to valproate and folate deficiency, making option A the best distractor to eliminate.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.