Pregnancy Diet and Allergy Risk
This February 2018 UK study wanted to investigate how variations in maternal or infant diet can influence risk of allergic or autoimmune disease. The study supported a relationship between maternal diet and risk of immune-mediated diseases in the child. Maternal probiotic and fish oil supplementation may reduce risk of eczema and allergic sensitisation to food, respectively.
This was a systematic review of past observation and intervention studies to consolidate all the past study findings. The review outcome was that probiotics during late pregnancy and breastfeeding may reduce risk of eczema, and fish oil supplementation during pregnancy and breastfeeding may reduce risk of sensitisation to food allergens.
The motivation for the study was partly because several studies' findings were conflicting and even recommendations from government bodies were different! It was noted in the paper that a recent World Allergy Organization guideline recommended probiotic (for high-risk cases) and prebiotic (for not exclusively-breastfed infants) supplements for eczema prevention, but European (EAACI), North American (AAP; an update paper in 2019 stated that the position in 2008 that there is no support for probiotics for reduced eczema risk during pregnancy will not be further discussed, as there is still lacking evidence to make any update position), and Australasian guidelines do not support this.
Again, for me, checking with gynecologist if you should include some probiotics and omega 3 in your diet if you are aware that your family history has eczema risk is probably a good thing to do. I sometimes do wish that I knew my spouse's family has history of eczema and alerted this to the gynecologist, maybe my daughter would not have eczema?
Here are some fish oil and probiotics pregnancy supplements:
Garden of Life Ultra Pure EPA/DHA Omega 3 Fish Oil - Oceans 3 Oceans Mom Dietary Supplement with Antioxidants
Nordic Naturals Prenatal DHA - Supports Brain Development in Babies During Pregnancy and Lactation*, Strawberry Flavored, Bonus Size, 120 Count
In the American Academy of Pediatrics 2019 paper, the conclusion on pregnancy diet was:
lack of evidence to support maternal dietary restrictions during pregnancy and lactation to prevent atopic disease
no short- or long-term advantages for exclusive breastfeeding beyond 3 to 4 months for prevention of atopic disease (check this forum post whereby prolonged breastfeeding may increase risk of food allergy)
exclusive breastfeeding for at least 3 to 4 months decreases the cumulative incidence of atopic dermatitis in the first 2 years of life. There is no evidence that longer duration of any breastfeeding affects the outcome.
lack of evidence that partially or extensively hydrolyzed formula prevents atopic disease in infants and children, even in those at high risk for allergic disease (check this forum post whereby partially hydrolyzed formula was associated with higher risk of food allergy and wheezing)
no convincing evidence of benefit to delay the introduction of allergenic foods beyond 4 to 6 months for the prevention of atopic disease, including peanuts, eggs, and fish; but strong evidence from a randomized trial that purposeful early introduction of peanuts (4 - 6 months old) may prevent peanut allergies in high-risk infants; Data to support beneficial effect of early introduction of eggs is less clear (check out this forum post for updated study)