Health Disparities
Quality of Antenatal Care and Pregnancy Outcomes: Gestational Diabetes and Preeclampsia Analysis in All of Us Participants Sueny Paloma Lima dos Santos* Sueny Paloma Lima dos Santos University of Missouri – Columbia
Background
The quality of antenatal care (ANC) determines maternal and fetal health outcomes, but researchers have not fully characterized its link to gestational diabetes mellitus (GDM) and preeclampsia. Both conditions significantly affect pregnancy outcomes and long-term maternal health.
Objective
To assess whether the quality of antenatal care (ANC), based on adherence to essential care components, is associated with the risk of gestational diabetes mellitus (GDM) and preeclampsia, overall and by race, among pregnant participants in the All of Us Research Program, Data Release v8.
Methodology
Pregnant participants (N = 900) were identified from electronic health records, procedures, medications, and surveys. Participants ranged in age from 17 to 50 years (mean, 35.0; SD, 6.5). The quality of ANC was defined using six elements: blood pressure measurement, urine protein testing, HbA1c testing, ultrasound exams, iron/folic acid supplementation, and adequacy of visits (≥8 visits, per WHO guidelines). Categories were: High — full adherence (≥8 visits and all components), Intermediate — missing ≤1 component but ≥4 visits, and None — fewer than four visits or missing ≥2 components. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) for GDM and preeclampsia, crude and adjusted for race, ethnicity, and maternal age. Interaction terms and stratified models were used to examine race-specific associations.
Results
Blood pressure was measured for all participants. Urine protein tests were performed on 88.2% of participants, HbA1c testing was nearly universal (> 99%), and ultrasounds were also almost universal (>99%). Additionally, 97.4% received iron or folic acid supplementation. However, only 56.4% met the benchmark of eight or more visits. Overall, 55.6% achieved high-quality ANC, 32.3% achieved intermediate quality, and 13.1% achieved low quality. The prevalence of GDM was 51.4% in the high-quality group, 55.7% in the intermediate group, and 57.4% in the low-quality group. The prevalence of preeclampsia was 65.4%, 57.4%, and 52.5%, respectively. Crude models showed no significant association between the quality of ANC and GDM; however, a higher quality of ANC was protective against preeclampsia (Intermediate OR = 0.65, 95% CI: 0.48–0.87, p = 0.005; None OR = 0.56, 95% CI: 0.38–0.84, p = 0.005). After adjustment, results remained consistent: the quality of ANC was not significantly associated with GDM but remained protective for preeclampsia (Intermediate OR = 0.69, 95% CI: 0.50–0.94, p = 0.017; None OR = 0.60, 95% CI: 0.39–0.94, p = 0.024). Importantly, race-stratified analyses revealed heterogeneity: among Black participants, an intermediate quality of ANC was associated with a significantly higher risk of GDM (OR = 3.86, 95% CI: 1.75–8.54, p < 0.001), a pattern not observed in other groups.
Conclusions
The quality of ANC, particularly adherence to recommended visit frequency, shows a protective role against preeclampsia. While no overall association was observed between the quality of ANC and GDM, disparities emerged by race: Black participants showed increased GDM risk with intermediate-quality ANC, which may suggest that ANC effectiveness may vary by racial group, with differential implications for metabolic versus hypertensive outcomes.
Implications
Only half of the participants achieved the benchmark of ≥8 visits, showing persistent gaps in maternal care coverage. Improving the quality of ANC could substantially reduce preeclampsia risk, while targeted strategies may be needed to address elevated GDM risk among Black women. Strengthening equitable access to complete, guideline-based ANC is a critical public health and policy priority to reduce maternal morbidity and disparities across diverse populations.