Women's health status in the year before conception (women's prepregnancy BMI and prepregnancy diabetes for HDP) were associated with elevated risk of GDM and HDP. However, maternal behaviors in the year before pregnancy did not predict GDM or HDP. This finding suggests that improving perinatal health may require interventions more than a year before conception, with an emphasis on cardiometabolic and mental health. For example, evidence exists that bariatric surgery reduces risk of gestational diabetes; however, women are recommended to wait at least 12 months before conceiving following surgery. Thus, bariatric surgery is not a viable intervention for women seeking to conceive within a year, but it may be for women seeking to conceive in 2 or more years. Alternatively, the set of commonly measured preconception behaviors may be insufficient to capture interventions that would improve preconception health and subsequent maternal outcomes. Receiving prepregnancy advice about improving health was associated with increased risk, suggesting that primary care and OB/GYN providers accurately target high-risk women for advice. However, although providers may accurately identify women for advice in the year before pregnancy, it may be unrealistic for women to make sufficient changes in the year before conception to reduce risk. Given the socioeconomic and racial and ethnic disparities in GDM and HDP diagnoses, structural and social interventions more than 1 year before pregnancy may be necessary for prevention.
As previous authors have reported, racial/ethnic and socioeconomic disparities exist in experiences of GDM or HDP and in preconception health indicators. Disparities in preconception indicators were minor for health behaviors and greatest for indicators of health care access (eg, insurance, check-up) and prepregnancy health status (eg, obesity, diabetes, hypertension), and non-White women were less likely to have optimal preconception health. Our results regarding the prevalence of GDM and HDP are consistent with other estimates based on older data.
Our study has limitations. First, PRAMS collects data on pregnancy outcomes and prepregnancy health retrospectively. We attempted to correct for this by using information from the birth certificate on GDM and HDP, which is more accurate. However, our study design precludes assessment of causality. Second, in addition to measuring behaviors retrospectively, information about prepregnancy behaviors is vague. For example, drinking once in the 3 months before pregnancy and drinking daily may represent different levels of risk, which we are unable to capture. Future studies should consider prospective measurement of behaviors of interest. Third, PRAMS is only able to capture whether women report a diagnosis of depression before pregnancy. Thus, women who experienced depression but did not seek care were not included. Prospective measurement of depressive symptoms would better characterize the relationship between preconception depression and HDP. Finally, PRAMS captures whether women had a prepregnancy diagnosis of hypertension, diabetes, or depression but not whether the disease was controlled (by medication, diet, or otherwise) or not. This information could be critical in understanding whether screening before pregnancy has the potential to reduce risk for women with chronic disease. Evidence for diabetes suggests that control of diabetes before pregnancy reduces risk of adverse outcomes, including preeclampsia. However, whether control of hypertension would prevent GDM is unknown.
Our study also has strengths. First, PRAMS was conducted on a representative sample of women who gave birth to live infants in participating states for 2016–2017, representing 83% of live births in the United States for included years. Second, use of PRAMS allows for comparison of preconception health indicators across a range of domains with existing recommendations for state monitoring of preconception health.
These results support previous calls to improve all women's health across the life course in addition to the focus on the year before conception.[1,5,27] Although some preconception health indicators identified women at higher risk, none were promising candidates for intervention in the year before pregnancy. For example, prepregnancy obesity was strongly associated with elevated risk of both HDP and GDM. However, interventions to promote weight loss through diet or exercise among women planning to conceive in the next year have been unsuccessful at preventing GDM or HDP,[14,15] which suggests that intervening to prevent or reverse obesity more than a year before women intend to conceive may be necessary to reduce risk of HDP and GDM. Additionally, in the PRAMS sample, only 60% of women planned their pregnancy. Thus, broader structural interventions to improve women's health may have a greater impact than targeted interventions for women who plan to conceive in the next year. Measuring these indicators in the year before pregnancy describes the status of preconception health in a population; however, to improve preconception health, we must act longer before pregnancy. Many policy models exist to improve overall health outcomes in all women of reproductive age (eg, Medicaid expansion under the Affordable Care Act, Federally Qualified Health Centers). Structural interventions are known to decrease the number of maternal deaths and may similarly improve maternal outcomes such as GDM or HDP, although evidence is limited. For example, states that expanded Medicaid under the Affordable Care Act experienced declines in maternal mortality rates following expansion. Conversely, states with fewer Planned Parenthood clinics or more restrictive abortion policies have higher maternal mortality rates. Policies to improve access may also decrease racial and ethnic disparities in pregnancy outcomes, as one study of infant mortality showed. Our study did not identify behavior changes in the year before pregnancy associated with decreased risk of HDP or GDM. This finding suggests that, although focusing on the year before conception may be a useful motivator for some women to improve their health, expanding, effectively implementing, and evaluating interventions to improve access to and utilization of care across the life course will be necessary to improve maternal outcomes.
Thank you to the CDC PRAMS Working Group and PRAMS participating states and respondents. This work was supported in part by Health Resources and Services Administration Maternal and Child Health Bureau, award no. T03MC07651. No copyrighted materials or tools were used in this research.
Prev Chronic Dis. 2021;18(1):e06 © 2021 Centers for Disease Control and Prevention (CDC)