Global prevalence of preterm birth among Pacific Islanders: A systematic review and meta-analysis

The epidemiology of preterm birth among Pacific Islanders is minimally understood. The purpose of this study was to estimate pooled prevalence of preterm birth among Pacific Islanders and to estimate their risk of preterm birth compared to White/European women. We searched MEDLINE, EMBASE, Web of Science Core Collection, Cochrane Library, CINAHL, Global Health, and two regional journals in March 2023. Observational studies were included if they reported preterm birth-related outcomes among Pacific Islanders. Random-effects models were used to estimate the pooled prevalence of preterm birth with 95% confidence interval (CI). Bayes meta-analysis was conducted to estimate pooled odds ratios (OR) with 95% highest posterior density intervals (HPDI). The Joanna Briggs Institute checklists were used for risk of bias assessment. We estimated preterm birth prevalence among Pacific Islanders in the United States (US, 11.8%, sample size [SS] = 209,930, 95% CI 10.8%-12.8%), the US-Affiliated Pacific Islands (USAPI, SS = 29,036, 6.7%, 95% CI 4.9%-9.0%), New Zealand (SS = 252,162, 7.7%, 95% CI 7.1%-8.3%), Australia (SS = 20,225, 6.1%, 95% CI 4.2%-8.7%), and Papua New Guinea (SS = 2,647, 7.0%, 95% CI 5.6%-8.8%). Pacific Islanders resident in the US were more likely to experience preterm birth compared to White women (OR = 1.45, 95% HPDI 1.32-1.58), but in New Zealand their risk was similar (OR = 1.00, 95% HPDI 0.83-1.16) to European women. Existing literature indicates that Pacific Islanders in the US had a higher prevalence of preterm birth and experienced health inequities. Learning from New Zealand's culturally-sensitive approach to health care provision may provide a starting point for addressing disparities. The limited number of studies identified may contribute to higher risk of bias and the heterogeneity in our estimates; more data is needed to understand the true burden of preterm birth in the Pacific region.