PhD Scientific Days 2026

Poster Session 2.T - Surgical Medicine

Maternal and Fetal Factors Associated with Gestational Age at Prenatal Detection of Congenital Heart Defects: A Multivariable Cohort Analysis

Name of the presenter

Szepesi, Olívia Lili

Institute/workplace of the presenter

Semmelweis University Department of Obstetrics and Gynecology

Authors

Olívia Lili Szepesi¹
1: Semmelweis University Department of Obstetrics and Gynecology

Text of the abstract

Introduction: Prenatal detection of congenital heart defects is critical for optimizing
perinatal outcomes, yet the gestational age at diagnosis varies considerably. The independent
contributions of maternal and fetal factors to detection timing remain poorly characterized.

Aim: To investigate the relationship between maternal and fetal parameters, to understand how these independent predictors may inform risk-stratified screening protocols.

Method: This study analyzed 903 pregnancies with confirmed CHD managed at a national tertiary referral center between 2005 and 2020. The primary outcome was gestational age at detection (in weeks). Predictor variables included maternal age, twin pregnancy, amniotic fluid abnormalities, chromosomal abnormalities including Down syndrome, and CHD severity. Univariable associations with binary predictors were assessed using Student's-, Welch's t-test, or Mann–Whitney U test based on distributional assumptions. Multivariable linear regression with heteroscedasticity-robust standard errors and backward elimination was applied to identify independent predictors while controlling for potential confounders.

Results: In univariate analyses, advanced maternal age (p<0.001), Down syndrome (p<0.001), and chromosomal abnormalities (p=0.0002) were significantly associated with earlier detection, while oligohydramnios was associated with later detection (p=0.0018). Twin pregnancy (p=0.13), polyhydramnios (p=0.43), and CHD severity did not show significant associations. In the multivariate regression model, only advanced maternal age (β=-0.20 weeks per year; p<0.001), Down syndrome (β =-1.70 weeks; p=0.011), and oligohydramnios (β =+2.59 weeks; p=0.005) remained independently associated with detection timing. The effects of twin pregnancy, polyhydramnios, and other chromosomal abnormalities were not statistically significant after adjustment for covariates.

Conclusion: Gestational age at prenatal CHD detection is independently influenced by maternal age, Down syndrome, and oligohydramnios. While several factors appeared significant in univariate analyses, multivariate modeling revealed that only a subset exerted independent effects. These findings underscore the importance of multivariate analytical approaches in prenatal diagnostic research and may inform risk-stratified screening protocols.

This study was not funded by any sponsor