Pregestational diabetes and fetal heart rate in the first trimester of pregnancy

Objective: The aim of our study is to evaluate if pregestational diabetes affects fetal heart rate (FHR) readings at 11–14 weeks of pregnancy. Study design: For each patient, we recorded age, body mass index (BMI), presence of pregestational diabetes, nuchal translucency (NT), FHR, crown-rump length (CRL), biparietal diameter (BPD) and gestational age. Pregnancies were grouped according to the presence or absence of pregestational diabetes and maternal and fetal variables were compared. Ordinal regression analysis was performed to assess the influence of maternal and fetal variables on the FHR. Results: We included 994 pregnancies from 2009 to 2016. Kruskal-Wallis test showed that median FHR was higher in women with pregestational diabetes than in controls (161; IQR 11 vs. 158; IQR 10, χ2 = 5.13, p = 0.02). Ordinal regression analysis showed that differences in FHR were significantly correlated with the presence of pregestational diabetes (p = 0.007) and the CRL (p = 0.042) but not with the maternal BMI, maternal age, gestational age, BPD and NT. Conclusions: First trimester FHR is higher in diabetic pregnancies than in non-diabetic pregnancies. Therefore, further research is needed to assess whether these pregnancies may benefit from a correction of FHR for a better estimation of the chromosomal abnormalities risk.