Maternal cardiac function at 19-23 weeks' gestation in prediction of gestational diabetes mellitus.

OBJECTIVES: To examine differences in maternal cardiovascular indices at 19-23 weeks' gestation between pregnancies that develop gestational diabetes mellitus (GDM) and those without GDM, and to determine whether such cardiovascular changes are the consequence of maternal demographic characteristics and medical history or GDM per se. METHODS: This was a prospective observational study in women attending for a routine hospital visit at 19 + 1 to 23 + 3 weeks' gestation. This visit included recording of maternal demographic characteristics and medical history, and maternal echocardiography for assessment of E/A ratio, E/e' ratio, myocardial performance index, global longitudinal systolic strain, left ventricular ejection fraction, peripheral vascular resistance, left ventricular cardiac output and left ventricular mass indexed for body surface area. The measurements of the maternal cardiac indices were standardized to remove the effects of maternal characteristics and elements from the medical history, and the adjusted values in the GDM group were compared to those in the non-GDM group. Likelihood ratios were derived for those indices that were altered significantly in GDM, and these were used to modify the prior risk derived from maternal demographic characteristics and medical history. The area under the receiver-operating-characteristics curve and the detection rate of GDM, at 10%, 20% and 40% false-positive rates, in screening by a combination of maternal factors with cardiovascular indices were determined. RESULTS: The study population of 2853 pregnancies contained 199 (7.0%) that developed GDM. In pregnancies that developed GDM, there were significant differences from the non-GDM group in E/A ratio, E/e' ratio, myocardial performance index and global longitudinal systolic strain. After adjustment for maternal demographic characteristics and factors from the medical history known to affect cardiac indices, the only cardiovascular indices that were significantly different between the GDM and non-GDM groups were peripheral vascular resistance and myocardial performance index, both of which were marginally increased in the GDM group. The performance of screening for GDM by maternal demographic characteristics and medical history was not improved by the addition of cardiovascular indices. CONCLUSIONS: Women with GDM have subtle functional and hemodynamic cardiac changes prior to the development of GDM. These cardiac changes are mostly related to the adverse risk-factor profile of these women. Maternal cardiac assessment at 20 weeks does not offer additional predictive information for GDM development in pregnancy to that calculated based on demographic characteristics and medical history. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.