Pregnancy is among the most sensitive and important stages in the life of parents, and childbirth is an important event in a woman's life. The duration of labour varies in different women and is affected by factors such as age, parity, foetal size and maternal weight (Chen et al., 2018).A prolonged first stage of labour entails complications such as compressed foetal head in the birth canal, lower neonatal Apgar score and foetal death (Allen et al., 2007). A prolonged second stage of labour is associated with increased frequency of caesarean section, tearing of the birth canal and damage to the perineal muscles (Brown et al., 2011). Moreover, a prolonged delivery is also associated with many other maternal complications such as uterine atony and increased maternal mortality, and foetal complications such as foetal distress and reduced foetal Apgar score (Direkvand-Moghadam & Rezaeian, 2012). Given that maternal and neonatal complications increase with the duration

Omega-3 fatty acids (FAs) are essential unsaturated long-chain FAs necessary for proper health and growth. The objective of the authors in this study was to evaluate the effect of fish oil supplementation in pregnancy on maternal serum FA profiles. Participants (n = 150 pregnant women aged 18-35 years in Tabriz, Iran) were randomly assigned to receive either 1,000 mg fish oil supplements daily containing 120 mg docosahexanoic acid (DHA) and 180 mg eicosapentaenoic acid (EPA), or placebo from week 21 of pregnancy to delivery. The primary outcome measures were mean serum DHA and EPA proportion of total FAs at weeks 35-37 of pregnancy. Analyses were based on intention-to-treat. No significant differences were observed between the groups in consumption of fish and serum FAs levels at baseline. Fish oil supplementation significantly increased the mean DHA proportion of total FAs in the intervention compared to the placebo group at weeks 35-37 [adjusted Mean Difference (aMD) = 0.15; 95% CI 0.08-0.23]. The mean EPA proportion of total FAs also increased in the intervention group, but the difference between the groups was not significant (aMD = 0.04; 95% CI -0.01 to 0.08). The dietary recommendation for consumption of 1,000 mg/day fish oil supplements during pregnancy seems beneficial for better serum FA composition.