Miscarriage After Detecting Fetal Heartbeat: Statistics and Causes

Detecting a fetal heartbeat (typically at 6–7 weeks transvaginally) is reassuring but does not guarantee a live birth.

• Overall miscarriage rate for clinically recognized pregnancies: 10–20% (most <12 weeks).
• After heartbeat detection at 6–7 weeks: Loss rate drops to ~5–10%.
• After 8 weeks with heartbeat: <3%.
• After 12 weeks: <1–2%.

Common Causes

• Chromosomal abnormalities (aneuploidy) — 50–60% of early losses.
• Uterine anomalies, thrombophilias, endocrine disorders (thyroid, diabetes).
• Infections, immune factors, advanced maternal age.

Management: Serial hCG, progesterone, early ultrasound. Progesterone supplementation may help in threatened miscarriage with bleeding and prior losses. Most women go on to have healthy pregnancies.