Conclusions
This study adds novel information about contact with primary care and glucose monitoring up to 3 years postdelivery. In a large, demographically and geographically diverse sample of continuously insured women, we found that 8.3% of index live birth deliveries were affected by GDM. DeSisto et al estimated a 9.2% prevalence based on self-report and birth certificate data for 2012,23 and a study of claims data in a similar sample produced a 7.2% estimate.17 Differences in estimates may reflect variations in time, sample selection, and restriction to live births.
GDM can herald T2DM and other chronic disease in later life. Specifically, all women with GDM are at high risk of T2DM, and diabetes is a significant and modifiable contributor to cardiovascular disease, the #1 cause of mortality in US women. Evolving data suggest that women who screen negative for glucose metabolism disorders during the postpartum period should be involved in primary prevention (diet and exercise programme).12 We found a 52.2% rate of subsequent GDM recurrence among those with a second delivery in 3 years, and a 7.6% rate of early conversion to T2DM within 3 years postdelivery. Despite this high risk, we report a low rate of postpartum glucose testing in the recommended period (5.8%) and few women with a postdelivery primary care visit (5.7% initially and 40.5% within 3 years). Primary care follow-up after delivery presents opportunities to delay T2DM or prevent deterioration or prevent complications associated with T2DM onset. Insurance access may be necessary for follow-up and prevention, but as this study shows, coverage is not sufficient to prevent gaps in the pathway to recommended care.
In our sample, rates of postpartum glucose testing during the recommended time period were extremely low, and only 60% of the women who were tested received the recommended oral glucose tolerance test (OGTT). Other tests commonly used in the postpartum period have important limitations: fasting blood glucose may only identify 40% of women with impaired glucose tolerance in a diverse population,24 and HbA1c, a more stable measure, may not be sufficiently specific because the time frame it measures can include the third trimester of pregnancy.9
This study confirms known low rates of postdelivery glucose testing, the high risk of GDM recurrence, and early T2DM onset.8 13 15 17 25 26 Early onset T2DM has been reported for 2%–28% of women with GDM within 5 years.27 In our study, the rate was 7.6% within 3 years, underscoring the substantial contribution of GDM to rates of T2DM, and the importance of follow-up. Study results suggest that continuous quality insurance coverage is not sufficient, in itself, to accomplish the necessary transition from obstetrics to primary care after delivery. Lifestyle changes and possibly early intervention with oral hypoglycemic agents can prevent or delay the onset of T2DM in women who have experienced GDM.28 29 The women in this large sample had continuous insurance coverage, yet still had unacceptably low rates of primary care follow-up (5.7% at 6 months, 13.2% at 1 year, and 40.5% at 3 years postdelivery), considering their high risk of GDM recurrence and early T2DM onset. Our study shows that women with GDM are not receiving specialized monitoring compared with women with no GDM, despite wide dissemination of guidelines requiring testing and referral for preventive care.
In the time since women’s healthcare was first described as a patchwork quilt with gaps in 1998,30 there has been little improvement in continuity of care across the life cycle. Transfer of patient care between obstetrics and primary care is still problematic. This large study of a high-risk sample of insured women demonstrates low rates of primary care contact prior to pregnancy and low rates of follow-up with glucose testing and primary care visits after delivery, despite coverage that should ensure access to coordinated care and clear guidelines for testing and referral issued by leading professional organizations. Pathways to care documented in this study demonstrate significant care gaps or incomplete care for the majority of women with GDM, including many of those who experienced new onset of T2DM during the follow-up period.
In a novel consensus meeting to establish research priorities, patients and clinicians in Alberta, Canada31 identified barriers to follow-up, including screening methods, risk communication, lifestyle challenges and the metabolic health of offspring. In a prior study, we interviewed patients and providers, and found a ‘perfect storm’ of missed opportunities.32 Others identify lack of information and multiple roles as patients, parents, jobholders, and family caregivers.33 Work is being done to refine risk calculation for more effective targeting of preventive measures.34 In the Translating Research Into Action for Diabetes study, Ferrara et al
8 successfully implemented a nurse-delivered reminder that raised glucose-testing rates, but other attempts at preventive intervention have encountered barriers to engaging and sustaining patients.35 36 Findings in this study argue for systems changes to create a more obvious pathway from primary care to obstetrics and back to primary care.
American Diabetes Association guidelines for postpartum glucose testing were revised in 2017 to include a 75 gm OGTT at 4–12 weeks instead of the former guidance to test at 42–84 days postdelivery.37 This change puts the time frame for glucose testing squarely within the purview of the obstetric clinician, and allows testing to occur concurrently with the postpartum visit. Under this guideline, a patient with a GDM-affected pregnancy would continue in the care of the delivering practitioner until results of the OGTT are obtained, the patient notified, and an appropriate referral made for follow-up. This new approach has the potential to resolve some of the major aspects of the gap between specialties, but it requires a change in traditional practices that may be slow to implement. An alternative would be to intensify efforts to connect women promptly and more effectively with primary care services. This study shows that women who have a primary care visit prior to conception have higher rates of connection with primary care after delivery. In our sample, 70% of women had neither glucose monitoring nor a primary care visit within 1 year after a GDM delivery, despite having an elevated risk for repeat GDM (52.2% of subsequent pregnancies) and early onset of T2DM (7.6%).
We have presented here key gaps and inconsistencies in care that have the potential to affect outcomes for a large sample of commercially insured women across a range of individual and systems factors. Fortunately, there are means for improvement within the grasp of most systems. Quality assessment of routine blood pressure monitoring for patients with hypertension is just one successful example. Follow-up after GDM could be enhanced by similar quality and accountability measures requiring that patients and providers discuss future risks and set up ongoing glucose testing and referral to primary care as a standard of practice.
Study limitations
We began with a diverse sample of 1 285 309 women with a live birth delivery, and winnowed down to 12 622 in order to meet study conditions. However, we were able to address potential effects of this reductive process on generalizability through comparisons of included versus excluded at each step, demonstrating no difference in key parameters or outcomes. This sample is continuously insured, as are 87% of reproductive-age women.38
Study strengths
Our findings document major gaps in the healthcare pathway. These missed opportunities for prevention emphasize the importance of strengthening the linkage between obstetrics and primary care.
