Racial/ethnic disparities, postpartum care
Neither long-term study – the NHS II or the HAPO Follow-Up Study – has looked at racial and ethnic differences. The HAPO cohort is racially-ethnically diverse but the NHS II cohort is predominantly white women.
Research suggests that GDM is a heterogeneous condition with some unique phenotypes in subgroups that vary by race and ethnicity. And just as there appear to be racial-ethnic differences in the pathophysiology of GDM, there appear to be racial-ethnic differences in the progression to type 2 diabetes – a known risk factor for cardiovascular disease, said Monique Henderson, PhD, a research scientist at Kaiser Permanente Northern California (KPNC).
On the broadest level, while Asian Americans have the highest prevalence of GDM, African Americans have the highest rates of progressing to type 2 diabetes, Dr. Henderson said. Disparities “may [stem from] metabolic differences in terms of insulin resistance and secretion that are different between pregnancy and the postpartum period, and that might vary [across racial-ethnic subgroups],” she said. Lifestyle differences and variation in postpartum screening rates also may play a role.
At KPNC, where women with GDM receive calls and letters reminding them of the need for postpartum screening, only 48% overall completed an oral glucose tolerance test at 4-12 weeks post partum, as recommended by both the American Diabetes Association and the American College of Obstetricians and Gynecologists. Both before and after adjustment for education, attendance at a postpartum visit, and other variables, Chinese women were most likely to have screening, and black women were least likely, said Dr. Henderson, referring to ongoing research.
A study Dr. Ehrenthal led of women with GDM or HDP recruited from the postpartum service of a large community-based, academic obstetrical hospital in Delaware showed that while nearly all women attended a 6-week postpartum visit with their ob.gyns., 59% of women with GDM had not yet completed diabetes screening when they were interviewed 3 months post partum. Most women with HDP indicated they had follow-up blood pressure testing, and just over half of women with either diagnosis recalled having ever had lipid testing (J Women’s Health 2014;23[9]:760-4).
Women least likely to complete screening tests were those who had no college education, those who had less than a high school level of health literacy, and those who were not privately insured, Dr. Ehrenthal said.
A large national study of privately insured women also found low rates of follow-up testing, however. While the majority of women with GDM had a postpartum visit with an obstetrician or primary care physician within a year after delivery, only a minority of women had a glycemic screening test completed (Obstet Gynecol. 2016;128[1]:159-67).
“We can’t place the blame on women,” Dr. Ehrenthal said. “We need increased attention to screening,” including screening for cardiovascular disease risk factors, and a “deliberate hand-off to primary care.”
For follow-up cardiovascular disease risk factor assessment after HDP, ACOG recommends periodic (perhaps annually) assessment and referral for treatment as needed, and the cardiology professional organizations recommend that pregnancy history be considered when assessing risk in order to decide on lipid treatment, she noted.
Each of the speakers reported that they have no financial or other interests that pose a conflict of interest. The HAPO Follow-Up Study is funded by the National Institute of Diabetes and Digestive and Kidney Diseases, and the nuMoM2b–HHS study has been funded by several National Institutes of Health institutes and other programs and initiatives.