To evaluate fetal ventricular morphology in pre-gestational overweight and obese women in the second and third trimester of pregnancy by two-dimensional speckle tracking imaging (2D-STI).

Eighty women with singleton pregnancy at Tangdu Hospital of Air Force Military Medical University from June 2019 to March 2020 were selected retrospectively. According to the pre-pregnancy body mass index (BMI), they were divided into a normal control group (n=30), an overweight group (n=27), and an obese group (n=23). All pregnant women underwent regular and two-dimensional speckle tracking (2D-STI) fetal echocardiography at 24 and 32 weeks of gestation. The 24-segment transverse diameters and spherical indexes (SI) of the left and right ventricle were measured by 2D-STI, and the routine fetal cardiac morphological indexes were obtained by regular fetal echocardiography. All data were compared using one-way ANOVA based on group. Post hoc analyses were performed between groups using LSD-t test.

There was no significant difference in left and right ventricular end-diastolic transverse diameters, left and right ventricular end-diastolic transverse length, cardiothoracic area ratio, and left ventricular stroke volume between any two of the groups by regular fetal echocardiography (P＞0.05). The interventricular septum diameter in the obese group in the second trimester was thicker than that in the normal control group [(2.10±0.41) mm vs (1.85±0.33) mm, P＜0.05], and that in the obese group in the late pregnancy was thicker than that in the control group and overweight group [(3.10±0.65) mm vs (2.46±0.52) mm and (2.55±0.53) mm, P＜0.05]. The segments 6-12 left ventricle transverse diameters measured by 2D-STI in the obese group at 24 weeks of gestation and the segments 7-12 values at 32 weeks of gestation were significantly wider than those in the control group at the same gestational age. The segments 4-12 left ventricular SI measured by 2D-STI in the obese group at 32 weeks of gestation was significantly lower than that in the control group (P＜0.05). The segments 3-10 right ventricle transverse diameter measured by 2D-STI in the obese group at 24 weeks of gestation and the segments 1-8 values at 32 weeks of gestation were significantly wider than those in the control group at the same gestational age, respectively. The segments 1-9 right ventricular SI measured by 2D-STI in the obese group at 32 weeks of gestation was significantly lower than that in the control group (P＜0.05).

Pre-pregnancy obesity can lead to wider transverse diameter and closer to the sphere in the middle segments of left ventricle and basal segments of right ventricle. It is suggested that the transverse diameters of left ventricular middle segments and right ventricular basal segments can more sensitively reflect the effect of pre-pregnancy obesity on fetal ventricular morphology.