Preterm Birth Among Pacific Islanders in the United States and the US-affiliated Pacific Islands: A Systematic Review and Meta-analysis

Objective: To better understand the epidemiology of preterm birth among Pacific Islanders in the United States and the US-Affiliated Pacific Islands.

Methods: Systematic searches of MEDLINE, Embase, CINAHL, PsycINFO, two nonindexed regional journals, and gray literature were conducted and finalized in September 2021. Observational studies published since January 2010 that documented preterm birth outcomes among Pacific Islanders in the United States and the US-Affiliated Pacific Islands were eligible for inclusion. Outcomes of interest included preterm birth prevalence, risk compared with white women, and risk factors for preterm birth among Pacific Islanders.

Results: Fourteen of the 3183 screened articles were included in meta-analyses. Random-effects models were used for pooled estimates with 95% confidence intervals. The pooled prevalence of preterm birth among Pacific Islanders was 11.2%, 95% CI: 9.3%-13.6%. Marshallese women had the highest pooled prevalence (20.7%, 95% CI 18.6%-23.0%) among Pacific Islander subgroups. Compared with white women, Pacific Islander women had higher odds of experiencing preterm birth (OR = 1.40, 95% CI: 1.28-1.53). Four risk factors for preterm birth could be explored with the data available: hypertension, diabetes, smoking, and pre-pregnancy body mass index; hypertension and diabetes significantly increased the odds of preterm birth.

Conclusions: Existing literature suggests that United States Pacific Islanders were more likely to experience preterm birth than white women, although the pooled prevalence varied by Pacific Islander subgroup. Data support the need for disaggregation of Pacific Islanders in future research and argue for examination of subgroup-specific outcomes to address perinatal health disparities.