Darling AM, et al. – The goal of this study was to assess the link between maternal dietary L–arginine intake and the rate of adverse birth outcomes. Findings highlighted that consumption of arginine was not related to fetal loss or giving birth to infants who were born small for their gestational ages.

Methods

• Researchers assessed the link between consumption of the amino acid arginine and the rate of adverse birth outcomes using data from a double-blind, randomized, placebo-controlled micronutrient supplementation trial among pregnant women in Dar es Salaam, Tanzania (2001–2004).  
• They assessed dietary intakes of arginine using repeated 24-hour recalls that were administered throughout pregnancy.
• Participants (n = 7,591) were monitored by research midwives throughout follow-up to assess pregnancy outcomes.
• In addition, they used cubic-restricted splines and multivariable log-Poisson regression with empirical standard errors to estimate the continuous and categorical associations between arginine intake and adverse birth outcomes.

Results

• Findings demonstrated that compared with women within the lowest quintile of arginine intake, those within the highest quintile had 0.79 times the risk of preterm birth before 37 weeks (95% confidence interval: 0.63, 1.00;P = 0.03).
• Researchers observed that the continuous associations of arginine intake with preterm birth before 37 weeks and with preterm birth before 34 weeks were characterized by an initial rapid decrease in risk with increasing intake (P for nonlinearity < 0.01).