Objective:To determine whether change in HbA1c from early to late pregnancy differs between non-Hispanic Black and White women with prepregnancy diabetes.
Study design:A retrospective analysis from an integrated prenatal and diabetes care program from 2012-2016. We compared HbA1c as a continuous measure, and secondarily, HbA1c<6.5%, cross-sectionally and longitudinally in early (~10 weeks) and late (~31 weeks) pregnancy. Linear and logistic regression were used, and adjusted for age, body mass index, White diabetes class, pharmacotherapy, diabetes type, gestational age at baseline HbA1c measurement, and baseline hemoglobin.
Results:Among 296 non-Hispanic Black (35%) and White pregnant women (65%) with prepregnancy diabetes (39% type 1, 61% type 2), Black women were more likely experience increased social determinants of health as measured by the Social Vulnerability Index (SVI), and were less likely to have type 1 diabetes and have more severe diabetes versus White women (p<0.05). Black women had higher mean HbA1c (7.8 vs. 7.4%; Beta: 0.75;95%CI: 0.30 to 1.19), and were less likely to have a HbA1c<6.5% at 10 weeks compared to White women (24 vs. 35%;AOR:0.45;95%CI: 0.24 to 0.81); but not after adjusting for SVI. At 31 weeks, both groups had similar mean HbA1c (both 6.5%) and were equally as likely to have a HbA1c<6.5% (57 vs. 54%). From early to late pregnancy, Black women had a higher percentage decrease in HbA1c (1.3% vs. 0.9%;Beta=0.63; 95%CI: 0.27 to 0.99), and were equally as likely to have an improvement or stable HbA1C <6.5% from 10 to 31 weeks, with both groups having a similar mean HbA1c (6.5%) at 31 weeks.
Conclusion:Despite experiencing greater community-level social determinants of health, Black women with pregestational diabetes had a larger reduction in HbA1c and were able to equally achieve target HbA1c<6.5% by late pregnancy compared to White women as part of an integrated diabetes and prenatal care prog