Objective To identify a polyunsaturated fatty acid (PUFA) biomarker able to detect which women with singleton pregnancies are most likely to benefit from omega‐3 supplementation to reduce their risk of early preterm birth. Design Exploratory analysis of a randomised controlled trial. Setting Six Australian hospitals. Population Women with a singleton pregnancy enrolled in the ORIP trial. Methods Using maternal capillary whole blood collected ~14 weeks’ gestation, the fatty acids in total blood lipids were quantified using gas chromatography. Interaction tests examined whether baseline PUFA status modified the effect of omega‐3 supplementation on birth outcomes. Main outcome measure Early preterm birth (<34 weeks’ gestation). Results A low total omega‐3 PUFA status in early pregnancy was associated with a higher risk of early preterm birth. Among women with a total omega‐3 status ≤4.1% of total fatty acids, omega‐3 supplementation substantially reduced the risk of early preterm birth compared with control (0.73 versus 3.16%; relative risk = 0.23, 95% confidence interval [CI] 0.07–0.79). Conversely, women with higher total omega‐3 status in early pregnancy were at lower risk of early preterm birth. Supplementing women with a baseline status above 4.9% increased early preterm birth (2.20 versus 0.97%; relative risk = 2.27, 95% CI 1.13–4.58). Conclusions Women with singleton pregnancies and low total omega‐3 PUFA status early in pregnancy have an increased risk of early preterm birth and are most likely to benefit from omega‐3 supplementation to reduce this risk. Women with higher total omega‐3 status are at lower risk and additional omega‐3 supplementation may increase their risk. Tweetable abstract Low total omega‐3 fat status helps identify which women benefit from extra omega‐3 to reduce early prematurity.

Objective: To assess dietary intake of pregnant women against the Australian Dietary Guidelines with respect to the Five Food Group recommendations and determine predictors of adherence to the recommendations. Design: Cross-sectional web-based survey. Data were analysed using descriptive statistics and logistic regression. Setting: Pregnant women living in Australia. A national sample was recruited using an online panel provider and a South Australian sample was recruited through the antenatal clinic of a large public maternity hospital. Subjects: A total of 857 pregnant women. Results: Fifty-six per cent, 29 % and less than 10 % of women met the recommendations for the fruit, dairy and other core food groups, respectively. None of the women met the recommendations for all Five Food Groups. Women who were born overseas and who were less physically active pre-pregnancy were less likely to adhere to the fruit and dairy recommendations. Women who smoked during pregnancy, were overweight pre-pregnancy and had lower household incomes were also less likely to meet the fruit recommendations; and women living in metropolitan areas were less likely to meet the vegetable recommendations. Sixty-one per cent believed their diet during this pregnancy was healthy. Conclusions: The majority of pregnant women in Australia perceive their diets to be healthy yet they do not consume the recommended daily servings from the Five Food Groups. Intervention strategies are warranted, particularly those that increase women's ability to evaluate their diet and also encourage positive dietary changes. These strategies may increase adoption of dietary guidelines and optimise pregnancy and other long-term health outcomes.

BACKGROUND Previous studies have suggested that maternal supplementation with n−3 long-chain polyunsaturated fatty acids may reduce the incidence of preterm delivery but may also prolong gestation beyond term; however, more data are needed regarding the role of n−3 long-chain polyunsaturated fatty acids in pregnancy. METHODS We performed a multicenter, double-blind, randomized trial in which women who were pregnant with single or multiple fetuses were assigned to receive either fish-oil capsules that contained 900 mg of n−3 long-chain polyunsaturated fatty acids (n−3 group) or vegetable-oil capsules that contained trace n−3 long-chain polyunsaturated fatty acids (control group) daily, beginning before 20 weeks of gestation and continuing to 34 weeks of gestation or delivery, whichever occurred first. The primary outcome was early preterm delivery, defined as delivery before 34 completed weeks of gestation. Other pregnancy and neonatal outcomes were also assessed. RESULTS A total of 5544 pregnancies in 5517 women were randomly assigned at six centers in Australia; 5486 pregnancies were included in the primary analysis. Early preterm delivery occurred in the case of 61 of 2734 pregnancies (2.2%) in the n−3 group and 55 of 2752 pregnancies (2.0%) in the control group; the between-group difference was not significant (adjusted relative risk, 1.13; 95% confidence interval [CI], 0.79 to 1.63; P = 0.50). There were no significant differences between the groups in the incidence of interventions in post-term (>41 weeks of gestation) deliveries, in adverse events, or in other pregnancy or neonatal outcomes, except that a higher percentage of infants born to women in the n−3 group than in the control group were very large for gestational age at birth (adjusted relative risk, 1.30; 95% CI, 1.02 to 1.65). Percentages of serious adverse events did not differ between the groups. Minor gastrointestinal disturbances were more commonly reported in the n−3 group than in the control group. CONCLUSIONS Supplementation with n−3 long-chain polyunsaturated fatty acids from early pregnancy (<20 weeks of gestation) until 34 weeks of gestation did not result in a lower incidence of early preterm delivery or a higher incidence of interventions in post-term deliveries than control.

Cord blood vitamin D was modestly, positively associated with language development in early childhood in our sample, although the magnitude of the association was small. Randomised controlled trials are needed to confirm a causal association and establish the potential clinical significance of the relationship between vitamin D status and language development.