Gestational Diabetes Linked to Fetal and Infant Cardiac Changes

Key Takeaways

• In this single-center cohort in China, gestational diabetes exposure in mid-pregnancy was associated with significantly thicker fetal left ventricular walls and interventricular septa than in healthy control pregnancies.
• Fetuses in the gestational diabetes group also had lower RVEF and TAPSE, with higher tricuspid E/e'.
• At about 42 days after birth, infants born after gestational diabetes exposure still had higher left ventricular E/e' and lower TAPSE than controls.
• Gestational age at assessment was similar between groups, and the reported null subgroup analysis of fetal and neonatal echocardiographic parameters within the GDM cohort was labeled inconsistently as diet-controlled versus insulin-treated and as with versus without insulin requirement.

Gestational diabetes leaves an open question about whether fetal exposure to maternal hyperglycemia produces measurable cardiac changes before birth and into early infancy. In this single-center cohort from China, pregnancies complicated by gestational diabetes were followed from mid-pregnancy fetal echocardiography into infant follow-up to assess structural and functional cardiac differences across that window.

At the First Affiliated Hospital of Nanjing Medical University in China, a prospective cohort study of gestational diabetes and fetal/infant cardiac echocardiographic findings enrolled 64 pregnant women with gestational diabetes mellitus (GDM) and 119 healthy pregnant controls from September 2023 through December 2024.

Fetal echocardiography was performed at 24 to 28 weeks of gestation, and infant echocardiography was repeated at about 42 days after birth. GDM was defined under Chinese guidelines using a single oral glucose tolerance test (OGTT), and pregnancies with major maternal or fetal conditions that could alter cardiac assessment were excluded. Investigators obtained a broad fetal echocardiographic panel, averaged diameters across repeated cardiac cycles, and had all images reviewed by a second physician.

Gestational age at scanning and maternal age did not differ significantly between groups, while maternal body mass index was higher in the GDM group. In utero, GDM exposure was associated with thicker fetal left ventricular walls and interventricular septa, along with lower right ventricular ejection fraction (RVEF), higher tricuspid E/e'—the ratio of early inflow velocity to early annular tissue velocity—and lower tricuspid annular plane systolic excursion (TAPSE), with between-group p < 0.05.

By about 42 days after birth, infants in the GDM group still had higher left ventricular E/e' and lower TAPSE than controls, again with between-group p < 0.05. Within the GDM cohort, no significant differences were reported in fetal or neonatal echocardiographic parameters between insulin-requiring and non-insulin-requiring subgroups, but this null finding does not establish equivalence between subgroups.

These findings are associations from an observational, single-center cohort with a relatively small sample and follow-up limited to early infancy at about 42 days. Maternal body mass index was higher in the GDM group, and the authors noted that multiple maternal and perinatal factors could influence offspring cardiovascular findings. Because the cohort was defined by Chinese diagnostic criteria, direct applicability to U.S. practice is uncertain even though the infant echocardiography protocol followed American Society of Echocardiography guidance.

In this cohort, gestational diabetes was associated with altered fetal cardiac morphology and function, with some functional differences still detectable in early infancy. The persistence signal centered on infant left ventricular E/e' and TAPSE.

Clinician Questions

How was gestational diabetes defined in this cohort?

Gestational diabetes mellitus was defined under Chinese guidelines by an oral glucose tolerance test, with fasting, 1-hour, and 2-hour thresholds of 5.1, 10.0, and 8.5 mmol/L; this describes how the cohort was defined in China rather than a universal diagnostic standard.

What exclusions narrowed this gestational diabetes fetal and infant cardiac cohort?

The cohort excluded pregnancies complicated by pre-eclampsia, intrauterine growth restriction, fetal congenital deformities, twin gestations, oligo/hydramnios, known genetic or chromosomal disorders, and abnormal fetal heart rhythms; recruitment occurred at 24 to 28 weeks of gestation, with infant follow-up at about 42 days after birth.

How extensive was the echocardiographic assessment after gestational diabetes exposure?

Investigators measured 17 fetal echocardiographic parameters spanning wall and septal thickness, systolic indices, and Doppler diastolic measures; infant echocardiography assessed ventricular dimensions, interventricular septal thickness, left ventricular ejection fraction, TAPSE, and diastolic indices, with fetal diameters averaged across three cardiac cycles and images reviewed by a second physician.

What does the diet-controlled versus insulin-treated gestational diabetes comparison add to these findings?

This was reported as a null subgroup analysis within the GDM cohort, but the paper labeled the contrast inconsistently as diet-controlled versus insulin-treated and as non-insulin-requiring versus insulin-requiring; no significant fetal or neonatal echocardiographic differences were reported, but this does not prove the subgroups were equivalent.