Prospective Study of Maternal Alcohol Intake During Pregnancy or Lactation and Risk of Childhood Asthma: The Norwegian Mother and Child Cohort Study

Abstract

Background Many women drink during pregnancy and lactation despite recommendations to abstain. In animals, alcohol exposure during pregnancy and lactation influences lung and immune development, plausibly increasing risk of asthma and lower respiratory tract infections (LRTIs). Studies in humans are few. Methods In the Norwegian Mother and Child Cohort Study, we examined maternal alcohol intake during pregnancy and lactation in relation to risk of current asthma at 36 months (49,138 children), recurrent LRTIs by 36 months (39,791 children) and current asthma at seven years (13,253 children). Mothers reported frequency and amount of alcohol intake each trimester and the first three months following delivery. We calculated adjusted relative risks (aRR), comparing children of drinkers to non-drinkers, using Generalized Linear Models. Results A total of 31.8% of mothers consumed alcohol during first trimester, 9.7% during second trimester and 15.6% during third trimester. Infrequent and low-dose prenatal alcohol exposure showed a modest statistically significant inverse association with current asthma at 36 months (aRRs ~0.85). No association was seen with the highest alcohol intakes during the first trimester when alcohol consumption was most common. Relative risks of maternal alcohol intake during pregnancy with recurrent LRTIs were ~1, with sporadic differences in risk for some metrics of intake, but without any consistent pattern. For current asthma at seven years, similar inverse associations were seen as with current asthma at 36 month but were not statistically significant. Among children breastfed throughout the first three months of life, maternal alcohol intake during this time was not significantly associated with any of the three outcomes. Conclusion The low levels of alcohol exposure during pregnancy or lactation observed in this cohort were not associated with increased risk of asthma or recurrent LRTIs. The slight inverse associations of infrequent or low-dose prenatal alcohol exposure with asthma may not be causal.

Causal pathways for asthma (CASPAR) – MoBa “a happy hunting ground”

“…We found that there was no association between maternal alcohol intake during pregnancy and the risk of asthma in the off spring 1 . In contrast, higher maternal mid-pregnancy level of vitamin D classified as a 25-hydroxyvitamin D level was associated with a modestly reduced risk of recurrent lower respiratory tract infections (LRTIs) by age three years, but was not associated with current asthma 2 .…”

Alcohol odor elicits appetitive facial expressions in human neonates prenatally exposed to the drug

“…Following the acquisition of alcohol-related fetal memories, different experiences are likely to reexpose the organism to ethanol's chemosensory attributes or the intoxicating effects of the drug. Probably, the most frequent experience is related with the fact that a significant number of mothers that drink during pregnancy continue to do so during breastfeeding [61,62]. Human babies detect small quantities of the drug in maternal milk (peak levels after maternal consumption of 0.3 g/kg ethanol: 60 mg/dl) [25].…”

Adverse health outcomes associated with fetal alcohol exposure: A systematic review focused on immune‐related outcomes

“…Most recently, Carson et al analyzed data from the Copenhagen Study on Asthma in Childhood, which recruited children born to women with a history of asthma. The three remaining longitudinal studies were from Norway, the United Kingdom (UK), and Japan . The Norwegian study assessed outcomes from the Mother and Child Cohort Study, which recruited pregnant women and followed up children until 7 years of age.…”