Maternal probiotic milk intake during pregnancy and breastfeeding complications in the Norwegian Mother and Child Cohort Study.
PURPOSE
During the time of breastfeeding, a third of all women contract (or: fall ill in) mastitis-the leading cause of precocious weaning. Recent studies indicate that probiotics intake may prevent mastitis by altering the breast's bacterial flora. The aim of this study was to examine whether probiotic milk intake during pregnancy is associated with less breastfeeding complications and longer breastfeeding duration.


METHODS
This study included 57,134 women, with live singleton term births, participating in the Norwegian Mother and Child Cohort Study. Probiotic milk intake during the first half of pregnancy was self-reported in a validated food frequency questionnaire at gestational week 22. At 6 month postpartum, women reported complications, including mastitis, and duration and exclusivity of breastfeeding. The association between probiotic milk intake and breastfeeding complications and duration was studied by adjusted logistic regression models.


RESULTS
Probiotic milk intake was associated with increased risk for mastitis [adjusted odds ratio (aOR) 1.09, 95% confidence interval (CI) 1.02-1.16] and for any breastfeeding problems during the first month (aOR 1.19, 95% CI 1.10-1.21). However, cessation of predominant (aOR 0.95, 95% CI 0.91-0.96) or any (aOR 0.79, 95% CI 0.75-0.84) breastfeeding earlier than at 4 months was less frequent in probiotic milk consumers than in non-consumers.


CONCLUSIONS
Even though probiotic milk intake during the first half of pregnancy was statistically associated with increased risk for breastfeeding complications, including mastitis, the association is probably not causal. Probiotics intake was namely associated with longer breastfeeding duration and there was indication of socioeconomic confounding. Further studies, i.e., large randomized-controlled trials, are needed to understand the association between probiotic intake and breastfeeding complications.
['Karlsson|Sofiia|S|', 'Brantsæter|Anne-Lise|AL|http://orcid.org/0000-0001-6315-7134', 'Meltzer|Helle Margrete|HM|http://orcid.org/0000-0002-3591-7017', 'Jacobsson|Bo|B|http://orcid.org/0000-0001-5079-2374', 'Barman|Malin|M|http://orcid.org/0000-0002-5317-2768', 'Sengpiel|Verena|V|http://orcid.org/0000-0002-3608-7430']
D000818:Animals D001942:Breast Feeding D002648:Child D015331:Cohort Studies D005260:Female D006801:Humans D008892:Milk D009035:Mothers D009664:Norway D011247:Pregnancy D019936:Probiotics
Probiotic milk intake Probiotics Breastfeeding complications The Norwegian Mother and Child Cohort Study Mastitis Cessation of breastfeeding