The associations of cola intake with adverse birth outcomes among pregnant women after assisted reproductive technology treatment and women naturally conceived: a birth cohort study.

The influence of cola intake on birth outcomes is unclear. This study sought to describe and compare the associations between cola intake and adverse birth outcomes among women following assisted reproductive technology (ART) and women spontaneously conceived (SC). Participants (736 ART women and 1,270 SC women) were from the Chinese National Birth Cohort collected in Anhui province. Cola intake was assessed by self-reported questionnaires at each trimester. Outcome measures including preterm birth (PTB) and low birth weight (LBW) were extracted from medical records. The association between cola intake during pregnancy and PTB was found using multivariable log-binomial regression in combined ART and SC women. Separately, for ART women, cola intake during pregnancy increased the risk of PTB (risk ratios were 2.10, 1.65, and 1.81 for all three trimesters, respectively, all p < 0.05), and cola intake in the 1st trimester increased the risk of LWB (risk ratio 2.58, 95% confidence interval 1.29 to 5.16). Cola intake during pregnancy was not associated with PTB or LBW for SC women. Our findings indicate a detrimental effect of cola intake during pregnancy on birth outcomes for ART women. Thus, avoidance of cola intake should be counselled by medical doctors in women prescribed with ART treatment.