Racial/Ethnic Differences in Gestational Diabetes and Its Association with Maternal and Neonatal Outcomes among Women in Hawai'i.

Objectives: To assess racial/ethnic differences in gestational diabetes mellitus (GDM) prevalence in Hawai'i.

Methods: This retrospective cross-sectional study included hospital deliveries at Kapi'olani Medical Center for Women and Children (Honolulu, Hawai'i) from 2009 to 2019. For birthing people with multiple deliveries during the study interval, only the last delivery was included. Birthing people with pregestational diabetes, delivery < 29 weeks, and multifetal gestations were excluded. GDM was identified through ICD-9 and -1 0 codes. Race and ethnicity were self-reported. Maternal body mass index (BMI) was recorded at delivery admission. GDM prevalence was determined for each race and the odds examined using logistic regression, also adjusting for maternal age and BMI. For analysis, three racial groups were sub-grouped into six ethnic categories as described: the three major racial groups were: (i) Asian, (ii) Native Hawaiian/Pacific Islander, and (iii) White. Six major ethnic sub-categories in the Asian racial group included: East Asians-identified as (1) Chinese/Taiwanese, (2) Japanese/Okinawan, (3) South East Asians identified as Filipino, (4) Native Hawaiian and (5) Pacific Islander identified as Micronesian/Samoan, and (6) White.

Results: Of 57,031 deliveries, 31,663 were included in this study. Overall crude prevalence of GDM was estimated at 11.7%. The three Asian ethnic sub-categories had approximately twice the risk of GDM when compared to Whites (Filipina: OR 2.59, 95% CI = [2.27-2.96], Chinese/Taiwanese: OR = 2.38, 95% CI = [2.01-2.82], and Japanese/Okinawan: OR = 1.71, 95% CI = [1.47-1.99]). Native Hawaiians also had higher GDM prevalence estimates compared to Whites (OR = 1.50, 95% CI = [1.31-1.71]), though there was no significant difference for Pacific Islanders (OR = 1.14, 95% CI = [0.97-1.33]).

Conclusions: Prevalence of GDM in hospitalized deliveries in Hawai'i's multi-ethnic population of women has increased nearly 2-fold in the last two decades. All Asian Americans remain at highest risk despite lower maternal BMI at delivery. NH women are younger yet have similar frequency of co-morbidities and comprise the largest proportion of GDM cases overall.