Maternal cardiac function in gestational diabetes mellitus at 35-36 weeks' gestation and 6 months postpartum

Objective: Women with gestational diabetes mellitus (GDM) are at increased risk for adverse cardiovascular outcome later in life. However, it is uncertain whether this increased risk is due to cardiovascular changes occurring during pregnancy and persisting thereafter or to an adverse underlying cardiovascular risk factor profile. Some studies have reported that GDM is associated with reduced systolic and diastolic left ventricular function in pregnancy; however, it remains unknown whether these changes persist after delivery. The objective of this study was to compare cardiac function and structure in women with GDM and those with uncomplicated pregnancy at 35-36 weeks' gestation and about 6 months after delivery.

Methods: This was a longitudinal study in which women with GDM and those with uncomplicated pregnancy had detailed cardiovascular assessment at 35-36 weeks' gestation and repeat examination around 6 months after delivery. In all women, left ventricular systolic and diastolic indices were measured and left ventricular mass indexed for body surface area was calculated. Cardiac output and peripheral vascular resistance were also calculated using echocardiography. Linear mixed model analysis accounting for differences in maternal characteristics was carried out to compare findings of cardiovascular function between the GDM group and controls and within each group at 35-36 weeks' gestation and at 6 months after delivery.

Results: We studied 73 women with GDM and 73 controls with uncomplicated pregnancy. At 35-36 weeks' gestation, women with GDM, compared to controls, had higher E/e' ratio and lower E/A ratio and global longitudinal systolic strain; there were no significant differences between the groups in ejection fraction. Left ventricular mass indexed for body surface area was also increased in women with GDM. There were no significant differences between the groups in cardiac output and peripheral vascular resistance. At 6 months after delivery, cardiac functional indices improved in both patients with GDM and controls, but in the GDM group, compared to controls, there was a lower degree of improvement in E/A ratio and global longitudinal systolic strain.

Conclusion: In the third trimester, patients with GDM have subtle differences in diastolic and systolic left ventricular function compared to controls and, despite improvement after delivery, these changes persist for at least 6 months. Long-term follow-up is therefore needed to assess whether women with GDM are at risk for an accelerated decline in their cardiac function and, if so, whether this trend can be reversed or delayed by optimal cardiovascular risk factor modification. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.