A 27-year-old woman with rheumatic mitral stenosis (valve area 1.4 cm2) has an uncomplicated pregnancy and delivers vaginally under epidural analgesia. When is she at greatest risk of acute cardiac decompensation?

• A During the second stage of labour
• B Risk is equal throughout pregnancy and the puerperium
• C At 20 weeks gestation when blood volume peaks
• D Immediately after cord clamping, extending through the first 24 to 48 hours postpartum ✓

Explanation

Immediately after delivery, relief of caval compression plus contraction of the uterus returns roughly 500 mL of blood to the circulation while the loss of the low-resistance placental circuit raises afterload. This autotransfusion peaks in the first 24 to 48 hours postpartum, making the immediate puerperium the classic danger period for women with fixed-output lesions such as mitral stenosis. Blood volume actually peaks earlier, around 30 to 34 weeks, not 20 weeks.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.