Objectives Women from the Philippines form one of the largest immigrant groups to North America. Their newborns experience higher rates of preterm birth (PTB), and separately, small-for-gestational age (SGA) birth weight, compared with other East Asians. It is not known if Filipino women are at elevated risk of concomitant PTB and severe SGA (PTB-SGA), a pathological state likely reflective of placental dysfunction and neonatal morbidity. Methods We conducted a population-based study of all singleton or twin live births in Ontario, from 2002 to 2011, among immigrant mothers from the Philippines (n=27 946), Vietnam (n=15 297), Hong Kong (n=5618), South Korea (n=5148) and China (n=42 517). We used modified Poisson regression to generate relative risks (RR) of PTB-SGA, defined as a birth <37 weeks' gestation and a birth weight <5th percentile. RRs were adjusted for maternal age, parity, marital status, income quintile, infant sex and twin births. Results Relative to mothers from China (2.3 per 1000), the rate of PTB-SGA was significantly higher among infants of mothers from the Philippines (6.5 per 1000; RR 2.91, 95% CI 2.27 to 3.73), and those from Vietnam (3.7 per 1000; RR 1.68, 95% CI 1.21 to 2.34). The RR of PTB-SGA was not higher for infants of mothers from Hong Kong or South Korea. Interpretation Among infants born to immigrant women from five East Asian birthplaces, the risk of PTB-SGA was highest among those from the Philippines. These women and their fetuses may require additional monitoring and interventions. ©Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Vietnam Immigrant Preterm birth East Asia Ethnicity race small for gestational age birthweight Filipina Philippines

Vietnam China South Korea Republic of Korea regression analysis Maternal Age twins human epidemiology Asian continental ancestry group Premature Birth statistics and numerical data premature labor ethnology marriage income Humans migrant Infant, Newborn male Emigrants and Immigrants female Viet Nam Infant newborn pregnancy Article Ontario Infant, Small for Gestational Age major clinical study adult small for date infant prematurity live birth cohort analysis Hong Kong parity Birth Weight Philippines gestational age