RISK of pre-eclampsia and large for gestational age infants was lower amongst pregnant females with Type 1 diabetes (T1D) who spent more time in optimal glucose range at 12 weeks gestation, according to new research. Time in range has been proven to have more advantages than traditional markers, meaning that more emphasis has been placed on evaluating this parameter as a marker for glycaemic control and predictor of outcomes in recent years. This information has the potential to change clinical management in both pregnant and non-pregnant populations.
The research team, lead by Nasim Sobhani, University of California, San Francisco, USA, conducted a multicentre retrospective cohort study, using data from 91 pregnant females with T1D using continuous glucose monitors, who gave birth from 2020–2022. All individuals had a continuous glucose monitor target range of 70 mg/dL–140 mg/dL. The researchers recorded time in range at 12, 16, 20, 24, 28, and 32 weeks. Primary outcomes measured were pre-eclampsia and infants born large for gestational age. Of this group, 81% of females used an insulin pump, and 72% did not have diabetes-related microvascular disease.
Overall, 29% of females developed pre-eclampsia. Results showed that normotensive pregnant females had a significantly higher time in range, from 56–62%, at most timepoints throughout gestation, compared to those with pre-eclampsia, with time in range from 43–50%. Additionally, 26% of females had large for gestational age infants. The team reported a similar pattern of higher time in range, from 55–64%, among females with normal birthweight infants compared with females with large for gestational age infants, with time in range from 41–47%. Every 5-unit time in range increase at 12 weeks gestation was associated with a 45% reduced risk for pre-eclampsia (adjusted relative risk: 0.55; 95% confidence interval: 0.30–0.99), and a 46% reduced risk for large for gestational age infants (adjusted relative risk: 0.54; 95% confidence interval: 0.29–0.99) in adjusted analyses.
Sobhani and team concluded that these findings have to potential to alter the ways in which clinicians counsel patients regarding risk of pregnancy complications, based on specific time in range. These results will also allow healthcare providers to provide encouragement to pregnant females with T1D, that even small changes in time in range can improve pregnancy outcomes. Sobhani added: “Efforts should be made to replicate these findings in a larger population, to establish evidence-based recommendation for time in range targets in pregnancy, and to explore the association between other continuous glucose monitor parameters and perinatal outcomes.”
