Persistent Adverse Pregnancy Outcomes Still Exist for Women With Type 1 or Type 2 Diabetes

Pregnant woman is using a glucometer at home.
Pregnancies among women with pre-existing diabetes are associated with preterm delivery and neonatal complications.

Pregnant women with type 1 or 2 diabetes continue to have adverse pregnancy outcomes that could possibly be prevented by modifying two major risk factors:  hyperglycemia and obesity, according to results of a national population-based cohort study, published in Lancet Diabetes and Endocrinology.

Diabetes in pregnancy can be associated with preterm delivery, birth weight extremes, and increased rates of congenital anomaly, stillbirth, and neonatal death.  In this study, researchers led by Helen R. Murphy, MD, of the University of North Anglia and King’s College in London, identified and compared modifiable risk factors associated with adverse pregnancy outcomes in women with type 1 diabetes (TD1) and those with type 2 diabetes (TD2).

“Our findings reinforce the crucial importance of maternal glycemia as a key modifiable risk factor and the negative effect of obesity in women with either type 1 or type 2 diabetes. Improving pregnancy outcomes is a shared challenge that will probably require new approaches for optimizing glycemic control and better integration of diabetes healthcare systems across primary care, pediatric and young adult clinics, and adult diabetes, obesity, and maternity services,” authors wrote.

The findings are based an analysis of data (collected during the National Pregnancy in Diabetes annual audits in the United Kingdom). The data was collected between 2014 and 2018 from 172 maternity clinics.

The study included 17,375 women of which 8,690 had T1D (85.3% White) and 8,685 had T2D (43.2% White). The mean age 32 years, , median BMI was 25.9 and 32.5 kg/m2 respectively at first antenatal visit, and median diabetes duration was 13 and 3 years, respectively.

700 congenital anomalies and 345 perinatal deaths were observed. Among deaths, 195 were stillborn and 150 were neonatal deaths.

Women with type 1 diabetes (T1D) were less likely to live in the lowest deprivation quantile (odds ratio [OR], 0.44; 95% CI, 0.35-0.55) compared with type 2 diabetes (T2D; OR, 0.73; 95% CI, 0.57-0.93) and were more likely to have a BMI <18.5 kg/m2 (OR, 1.27; 95% CI, 0.71-2.29) than women with T2D (OR, 0.86; 95% CI, 0.36-2.10).

Fewer women with T2D took 5 mg folic acid before conception (22.2% vs 44.1%; P <.0001) but were more likely to be on statins (5.3% vs 1.5%; P <.0001) or angiotensin-converting-enzyme inhibitors (4.1% vs 1.2%; P <.0001) compared with T1D, respectively.

More women with T2D had glycated hemoglobin <6.5% during the first (36.5% vs 15.9%; P <.0001) and third (73.7% vs 41.7%; P <.0001) trimesters than T1D, respectively.

Preterm births were associated with T1D (<37 weeks: 42.5% vs 23.4%; P <.0001; <34 weeks: 9.2% vs 5.1%; P <.0001). Larger babies (>90th percentile) were associated with T1D (52.2% vs 26.2%; P <.0001) and smaller babies (<10th percentile) with T2D (5.4% vs 14.1%; P <.0001).

Admittance to both the special (30.6% vs 17.9%; P <.0001) and intensive (12.7% vs 7.8%; P <.0001) care units were increased among babies born to women with T1D. Neonatal deaths were decreased among babies born to women with T1D (0.7% vs 1.1%; P =.013). Rates of stillbirths (1.0% vs 1.3%; P =.072) and congenital anomalies (4.5% vs 4.0%; P =.17) did not differ among T1D and T2D cohorts, respectively.

This study was limited by its relatively high amount of missing data and disparities of data collection between clinics or patient groups; for instance, fewer glycemic assessments were administered to women with T2D.

These results indicated that pregnant women with type 1 or 2 diabetes had persistently poor outcomes including preterm deliveries and stillbirths.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.


Murphy H R, Howgate C, O’Keefe J, et al. Characteristics and outcomes of pregnant women with type 1 or type 2 diabetes: a 5-year national population-based cohort study. Lancet Diabetes Endocrinol. 2021;9(3):153-164. doi:10.1016/S2213-8587(20)30406-X.