National Pregnancy in Diabetes Audit 2021 and 2022 (01 January 2021 to 31 December 2022)

There have been notable improvements in maternal glucose and pregnancy outcomes. These are associated with the increased use of continuous glucose monitoring (CGM) systems before and during pregnancy. Women with type 1 diabetes using CGM showed improvements in glucose control compared to women not using CGM, with more women achieving the NICE HbA1c target of <48mmol/mol during early pregnancy (25.5 vs 22.4%), and considerably more women achieving the pregnancy HbA1c target of <43mmol/mol after 24 weeks gestation (35.1 vs 25.3%).

These changes in maternal glucose were associated with improved maternal and neonatal health outcomes including fewer diabetic ketoacidosis events (2021 1.6%, 2020 2.8% and 2014 to 2019 2.9%), reductions in preterm births (2021 and 2022 41.4% vs 2019 and 2020 47.1%), reductions in large for gestational age babies (2021 and 2022 48.9% vs 2019 and 2020 54.5%) and reductions in neonatal care unit admissions (2021 and 2022 46.2% vs 2019 and 2020 55.4%).

Notably, for women with type 1 diabetes on CGM during 2021 and 2022, this was accompanied by a significant reduction in the serious adverse outcomes that are most important to women living with diabetes, such as birth defects and baby deaths (on CGM 4.4% vs not on CGM 6.2%). The reduction in serious adverse pregnancy outcomes and improvements in neonatal outcomes are attributed to improvements in maternal glucose since other markers of preparation for pregnancy (e.g. 5mg folic acid supplementation) are unchanged.

By 2022, 95% of pregnant women with type 1 diabetes were using wearable glucose monitoring systems (69% real-time CGM, 26% intermittently scanned CGM) but there were unexpected socio-economic and ethnic disparities. Furthermore, despite strong evidence that real-time CGM use has similar benefits for insulin pump and multiple daily injection users, women using insulin pumps were more likely to use real-time CGM compared to multiple daily injection users (74% vs 53%). It is likely that more advanced diabetes technology (i.e. hybrid closed-loop systems) will be needed to further improve pregnancy outcomes.

Women with early-onset type 2 diabetes now make up 56% of diabetes' pregnancies (compared to 47% in 2014). They face additional healthcare inequalities with 63% living in the 2 most deprived quintiles (7% in the least deprived quintile) and 53% belonging to ethnic minorities. They are older with a shorter duration of diabetes and higher BMI than mothers with type 1 diabetes; (median age 35 years, diabetes duration 3 years, BMI 33kg/m²). Most were treated using metformin alone (49.5%), with smaller proportions managed more intensively with insulin in combination with metformin (9.9%) or insulin alone (4.6%). Only 55% achieved the pregnancy HbA1c target of <43mmol/mol after 24 weeks gestation, unchanged since 2014.

During 2022, women with early-onset type 2 diabetes experienced increasing rates of serious adverse pregnancy outcomes compared to previous years (2022 6.6%, 2021 4.9%, 2020 and previous years 5.5%) including more birth defects and more baby deaths (stillbirths and neonatal deaths).

Among women with early-onset type 2 diabetes, very small increases in maternal glucose after 24 weeks gestation were associated with higher rates of perinatal deaths across all HbA1c categories between 43-80mmol/mol. In contrast to the improvements in maternal glucose and pregnancy outcomes in type 1 diabetes, women with early-onset type 2 diabetes had no improvement in maternal glucose (55% between 2014 and 2022), and experienced higher rates of serious adverse pregnancy outcomes (from 4.9% to 6.6%, see Figure 2).

The widening gaps in access to specialist diabetes teams are pertinent before and during pregnancy. After 7 years without progress, during 2021 and 2022 women with type 1 diabetes were more likely to be well prepared for pregnancy (17.6% vs 13.4%), due to more women achieving the early pregnancy target of HbA1c <48mmol/mol. However, among women with early-onset type 2 diabetes, only 9.5% were well prepared for pregnancy as compared to over 11% in previous years. Furthermore, most were taking prescribed glucose lowering therapy (64%), meaning that they had contact with health care professionals.

Over 9 years of NPID records (2014 to 2022), there has been no improvement in the proportions of women prescribed supplementation with 5mg of folic acid before pregnancy to reduce their risk of birth defects (44% in type 1 and 21% in type 2 diabetes). Nor has there been any reduction in the proportions of women taking potentially harmful medications (including treatments for blood pressure, lipids and newer diabetes therapies which are not approved for use during pregnancy) 3% type 1 and 12% early-onset type 2 diabetes. NICE recommend that pre-pregnancy weight management programmes should be offered to those with BMI above 27 kg/m². It was notable that among women with early-onset type 2 diabetes median BMI was 33kg/m² during early pregnancy. They were also more likely to experience delays in referral to specialist maternity clinics and were typically seen 3 weeks later during pregnancy than those with type 1 diabetes (median 6 weeks gestation in type 1 vs 9 weeks gestation in type 2 diabetes).

The socio-economic gradient is noticeable for women with both types of diabetes, with approximately twice as many well prepared pregnancies among women living in the 2 least deprived quintiles vs the 2 most deprived quintiles (41.4% vs 16.9% type 1, 34.7% vs 18.6% type 2). There are also ethnic disparities, with Black women being the least well prepared ethnic group in both types of diabetes (6.3% type 1, 7.5% type 2).