A 26-year-old woman at 8 weeks gestation presents with painless vaginal spotting for 2 days. Speculum examination shows a closed internal os. Ultrasound shows a live intrauterine fetus matching dates. She asks about the outcome of this pregnancy. The single best predictor of whether the pregnancy will continue is:

• A Maternal serum hCG level
• B Progesterone level
• C Amount of vaginal bleeding
• D Presence of fetal cardiac activity on ultrasound ✓

Explanation

This is a threatened abortion. Demonstration of fetal cardiac activity on ultrasound is the strongest predictor of continued viability; with a live fetus at 8 weeks, roughly 85 to 90 percent of such pregnancies progress to term. Bleeding volume correlates loosely with risk but does not override sonographic evidence of viability. Serum hCG and progesterone are adjunctive tests that cannot confirm ongoing viability once cardiac activity is visualised.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.