Cord insertion anomalies and adverse pregnancy outcomes: more than an incidental finding.

OBJECTIVE

The aim of this study was to investigate the importance of routine evaluation of cord insertion during the prenatal period. To this end, the perinatal outcomes of marginal and velamentous cord insertions were compared to normal cord insertions.

METHODS

We conducted a retrospective cohort study of singleton pregnancies delivered after 24 weeks between 2016 and 2023, comparing marginal and velamentous cord insertions diagnosed on second-trimester ultrasound with normal cord insertions in terms of preterm birth and adverse perinatal outcomes, after excluding cases with fetal anomalies, placenta previa, placental invasion, vasa previa, or multiple gestations.

RESULTS

Among 6,675 singleton pregnancies, 367 (5.5%) had marginal cord insertion and 45 (0.7%) had velamentous cord insertion. Marginal cord insertion was associated with a nearly threefold higher risk of preterm birth before 37 weeks, while no significant differences were observed for other adverse outcomes. In contrast, velamentous cord insertion was linked to significantly increased risks of preterm birth, primary cesarean delivery, low Apgar scores, and neonatal intensive care unit admission compared with normal cord insertions.

CONCLUSION

Marginal and velamentous cord insertions showed associations with preterm birth and certain adverse perinatal outcomes. Routine evaluation of cord insertion may provide useful information for clinical follow-up.

CLINICAL TRIAL REGISTRATION: This study was retrospectively registered and authorized by the local Ethics Committee of Ankara University (clinical trial date 19.08.2025; number: 1942038).