Investigating the factors associated with preterm birth using evidence from the Growing Up in New Zealand cohort: a retrospective geospatial study

This is the authors' abstract. We don't add key points for this paper.

Preterm birth (PTB) is a major public health concern with multifactorial causes. Modifiable factors, including nutrition and environmental influences, present opportunities for targeted intervention. This study examined associations between sociodemographic, nutritional, and environmental factors and PTB in a cohort of New Zealand (NZ) women. Data from 6822 mothers in the Growing Up in New Zealand cohort (2009–2010) were analysed to assess associations between sociodemographic characteristics, adherence to NZ food and nutrition guidelines, dietary patterns, micronutrient supplementation, and environmental factors (Healthy Location Index [HLI]) with PTB. Logistic and multilevel models were applied using RStudio. Of 6667 births, 436 (6.6 %) were preterm. Most sociodemographic factors, including maternal age, parity, BMI, ethnicity, and area-level deprivation, were not significantly associated with PTB. Non-adherence to breads and cereals Ministry of Health guidelines reduced odds (OR = 0.64; 95 % CI: 0.43, 0.91; p = 0.01), while a ‘Junk’ dietary pattern (OR = 1.28; 95 % CI: 1.07, 1.52; p = 0.007) and not taking iron supplements after the first trimester (OR = 1.46; 95 % CI: 1.06, 2.00; p = 0.02) increased odds. Residing in rural areas with moderate urban influence also increased odds (OR = 2.44; 95 % CI: 1.18, 4.66; p = 0.01). HLI demonstrated no significant associations. Adherence to recommended food groups (breads and cereals), junk dietary patterns, low iron supplement intake after the first trimester, and rural residence with moderate urban influence were associated with increased PTB odds. Addressing maternal nutrition and geographic disparities could help mitigate this risk. • Low adherence to breads & cereals food and nutrition guidelines lowered preterm birth odds. • Higher ‘Junk’ dietary pattern adherence increased preterm birth odds by 15–28 %. • Lack of iron supplementation post-first trimester increased preterm birth odds by 43–47 %. • Moderate urban-influenced rural areas had higher preterm birth odds than urban areas. • Environmental features showed no significant association with preterm birth risk.