Maternal and neonatal complications in pregnancies with and without pre-gestational diabetes mellitus

Objectives
To compare pregnancy complications in pregnancies with and without pre-gestational diabetes mellitus (DM) managed in a multidisciplinary high-risk diabetes antenatal clinic.

Methods
This screening cohort study was undertaken at a large maternity unit in the United Kingdom between January 2010 and December 2022. We included singleton pregnancies that booked at our unit at 11–13 weeks’ gestation. Univariate and multivariate logistic regression analysis was carried out to determine risks of complications in pregnancies with type 1 and type 2 DM after adjusting for maternal and pregnancy characteristics. Effect sizes were expressed as absolute risks (AR) and odds ratio (OR) (95 % confidence intervals [CI]).

Results
The study population included 53,649 singleton pregnancies, including 509 (1.0 %) with pre-existing DM and 49,122 (99.0 %) without diabetes. Multivariate logistic regression analysis demonstrated that there was a significant contribution from pre-existing DM in prediction of adverse outcomes, including antenatal complications such as fetal defects, stillbirth, preterm delivery, polyhydramnios, preeclampsia and delivery of large for gestational age (LGA) neonates; intrapartum complications such as caesarean delivery (CS) and post-partum haemorrhage; and neonatal complications including admission to neonatal intensive care unit, hypoglycaemia, jaundice and hypoxic ischaemic encephalopathy (HIE). In particular, there was a 5-fold increased risk of stillbirth and HIE.

Conclusions
The maternal and neonatal complications in pregnancies with pre-existing DM are significantly increased compared to those without DM despite a decade of intensive multidisciplinary antenatal care. Further research is required to investigate strategies and interventions to prevent morbidity and mortality in pregnancies with pre-gestational DM.