Laterality Spectrum Disorders in the Prenatal Era: Outcomes Across the Severity Spectrum and Associations with...

This study aimed to describe severity-stratified early outcomes in pregnancies with prenatally suspected laterality spectrum disorders (LSD), defined as abnormalities of left-right body patterning affecting thoracoabdominal situs and associated cardiovascular and visceral structures, and to explore phenotype patterns associated with pregestational diabetes mellitus (PDM).

Retrospective cohort study of pregnancies evaluated at a tertiary fetal care and fetal cardiology referral center (2010-2026). LSD subtype was assigned using a prespecified operational framework. Cardiac severity was classified as major versus nonmajor congenital heart disease (CHD). Outcomes included termination, intrauterine fetal demise (IUFD), neonatal survival (≤28 days), infant survival (28 days-1 year), cardiac surgery, and gastrointestinal morbidity.

Seventy-eight pregnancies were included; 16/78 (20.5%) had PDM. Major CHD was present in 49/78 (62.8%). Pregnancy outcomes included live birth in 62/78 (79.5%), IUFD in 5/78 (6.4%), and termination in 11/78 (14.1%); all terminations occurred among major CHD cases. Among live births, neonatal survival was 59/62 (95.2%), and infant survival among neonatal survivors was 46/53 (86.8%). In major CHD live births (n = 33), neonatal survival was 30/33 (90.9%) and infant survival among neonatal survivors with available follow-up was 20/27 (74.1%). Cardiac surgery occurred in 22/62 (35.5%) and was more common in major versus nonmajor CHD (63.6 vs. 3.4%). Intestinal malrotation occurred in 18/62 (29.0%). Abdominal situs inversus was more frequent in PDM pregnancies (37.5 vs. 8.1%).

In LSD, major CHD drives pregnancy termination, surgical intervention, and early mortality concentrated during infancy. PDM was associated with a higher frequency of abdominal situs phenotypes, supporting deliberate postnatal gastrointestinal surveillance planning.

· In LSD, infant outcomes vary with CHD severity.. · Major CHD drives termination/surgery.. · PDM occurs across the LSD spectrum..