Chorionic Bump: An Early Ultrasound Marker for Adverse Obstetric Outcome.

Backgrounds/aims: To assess the perinatal outcome of pregnancies with chorionic bump detected at the first trimester of pregnancy.

Methods: This was a nested case-control study of pregnancies with chorionic bump identified at the first trimester ultrasound that was performed from October 2014 and October 2016. The control group consisted of the following 5 unaffected pregnancies after each case. From the first trimester ultrasound, maternal and perinatal characteristics were obtained and stored in a dedicated database. The primary outcome was defined as the presence of an alive new-born. Secondary outcome was defined as the presence of a composite adverse obstetric outcome.

Results: Eleven first trimester pregnancies affected by a chorionic bump and 55 controls were identified. The primary outcome was observed in 72.7 and 89.1% of chorionic bump and controls respectively (p = 0.2). The secondary outcome was observed in 45.5% of pregnancies with a chorionic bump versus 12.7% in the unaffected group (p = 0.01). First trimester uterine artery Doppler demonstrated a non-significant trend to be higher in the chorionic bump group.

Conclusions: The presence of a chorionic bump is associated with a significant higher risk of adverse perinatal outcome.