Pre-pregnancy dietary patterns and risk of preterm birth and low birth weight: findings from the Australian Longitudinal Study on Women’s Health Dereje G. Gete *, Michael Waller, Gita D. Mishra School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, Australia Findings from previous studies on associations between pre-pregnancy dietary patterns and preterm birth and low birth weight (LBW) are limited and inconsistent. This study aimed to examine the association between pre-pregnancy dietary patterns and the risk of preterm birth and LBW. This study included 3422 and 3580 singleton live births from the Australian longitudinal study on women’s health (ALSWH) for the analyses of preterm birth and LBW, respectively. We used factor analyses and the healthy eating index-2015 (HEI-2015) score to derive maternal dietary patterns. Four dietary patterns were identified with factor analyses: meats and high-fats; prudent diets; sugar, refined grains, and processed foods; and traditional vegetables. Preterm birth and LBW were assessed using maternal reports from ALSWH data between 2003 and 2015. Greater adherence to traditional vegetables pattern before pregnancy was associated with a lower risk of preterm birth and spontaneous preterm birth after adjustments for lifestyle factors and pregnancy complications, highest vs lowest tertile (AOR= 0.72, 95%CI: 0.53, 0.99) and (RRR= 0.62, 95% CI: 0.38, 1.00), respectively. However, these associations were attenuated by the pre-pregnancy body mass index (BMI). No significant associations were observed between pre-pregnancy dietary patterns and LBW. This study suggests that better adherence to traditional vegetables pattern before pregnancy may have a beneficial effect on lowering the risk of preterm birth, particularly spontaneous preterm birth. This finding warrants further examination.