Risk factors for preterm and small-for-gestational-age babies: a cohort from the Pacific Islands Families Study

To explore risk factors that are associated with preterm birth and full-term small-for-gestational-age (SGA) birth for a Pacific population.

Data were gathered from the Pacific Islands Families Study. Mothers of a cohort of 1398 Pacific infants born in South Auckland, New Zealand during 2000 were interviewed when their infants were 6 weeks old. Mothers were questioned regarding maternal health, antenatal care and life-style behaviours. Data regarding birth outcomes were obtained from hospital records. Analyses focused on 1324 biological mothers who gave birth to a singleton and had valid data for birth outcomes.

Of 1324 singleton infants, the mean birthweight was 3.60 kg with standard deviation of 0.60 kg. Fifty-two (3.9%) had birthweight less than 2500 g. Ninety-four (7.1%) were born at less than 37 weeks of gestation. Most socio-demographic factors were not associated with poor birth outcomes. Primiparous birth, less frequent attendance of antenatal care and mother's history of high blood pressure were associated with preterm birth and SGA. Smoking during pregnancy increased the odds of having an SGA but not preterm birth. On the other hand, unplanned/unsure pregnancy and prior early pregnancy loss were associated with preterm birth but not SGA.

Corroborating research conducted with other populations, most of the internationally and nationally recognised risk factors for preterm birth and SGA are also important for Pacific people. Smoking seems to explain more poor birth outcomes in Pacific Islands than in the New Zealand population as a whole.