Pregnancy and perinatal outcomes in pregnancy with diagnosis of chorionic bump on first-trimester sonography: a systematic review and meta-analysis

Objective: To assess the relationship between the presence of the sonographic finding of chorionic bump (CB) during first trimester and miscarriage rate or other perinatal outcomes. Methods: PubMed, Medline, Embase, Cinahl and Clinicaltrials.gov databases, from inception to April 8, 2021 were explored utilizing combinations of the relevant medical subject heading (MeSH) terms, key words, and word variants for “CB” and “pregnancy.” Prospective and retrospective case-control studies were eligible for inclusion. Odds ratios (ORs) comparing obstetrical outcomes among pregnancies with CB and normal pregnancies were determined with 95% confidence intervals (CI) using random‐effects models. Primary outcome of interest was miscarriage rate. Secondary outcomes were: alive newborns (ANB) rate, adverse pregnancy outcomes (APO) and vaginal bleeding. Quality assessment of the included studies was performed using the Newcastle‐Ottawa Scale. Results: Five studies including 173 pregnant women with CB (study group) and 1,263 pregnant women without CB (control group) were included. Pregnancies affected by CB resulted to be associated with a significantly higher miscarriage rate (43.3% vs 20.7%; OR 2.95 95% CI 2.02–4.31, p <.00001), and conversely with a significantly lower rate of ANB (60.3% vs 82%; OR 0.35 95% CI 0.20–0.63, p =.0004). In addition, the risk of APO was around three-fold higher in the study group (52.2% vs 4.12%; OR 2.98 95% CI 1.04–8.51, p =.04), while the rate of vaginal bleeding was higher in the study group, without reaching a statistical significance (48% vs 16.4%; OR 2.21 95% CI 0.64–7.65 p =.21). Discussion: The presence of CB at first trimester ultrasound significantly increases the risk of miscarriage and APO, and intact the rate of ANB. This article is protected by copyright. All rights reserved. Key message: The presence of CB on early first trimester ultrasound increases three-fold the risk of miscarriage and adverse pregnancy outcomes and reduces the rate of alive newborns. It is important to consider CB as an ultrasound marker that requires a close surveillance throughout pregnancy to prevent long-term complications and provide adequate counseling to the patient.