Both prenatal and post-natal exposure to antibiotics was associated with an increased risk of asthma. The potential role of adverse effects of antibiotics on the gut microbiota and the development of asthma should be further explored.

The aim of the study was to assess whether perinatal factors are associated with the risk of asthma in childhood in a register-based, nested case-control study in Finland. All children born between January 1, 1996, and April 30, 2004, who were entitled to a special reimbursement for antiasthmatic drugs (i.e., had diagnosed asthma by 2006 and had purchased inhaled corticosteroids or montelukast at least once), were identified (n = 21,038). For each case, one matched control child was selected. The associations between perinatal factors, derived from the Finnish Medical Birth Register, and the risk of asthma were analyzed by conditional logistic regression. In the final multivariate model, maternal asthma, young age, smoking, previous miscarriages, and a high number of previous deliveries, as well as cesarean section, low gestational age, and low ponderal index, were associated with an increased risk of asthma in children diagnosed before the age of 3 years. Among children diagnosed at the age of 3 years or later, maternal asthma, low gestational age, and low ponderal index were associated with an increased risk, and a high number of previous deliveries was associated with a decreased risk of asthma. In conclusion, perinatal factors play a role in the development of asthma in childhood, but the etiology may differ in early and late-onset asthma.

Proper nutrition during pregnancy may be important for maternal health and fetal growth and development. In Finland, targeted recommendations are given to guide pregnant women in their food choice and dietary supplement use so that they may obtain adequate nutritional status and meet the increased need for nutrients. The aims of the present study were to examine food choices, nutrient intake and dietary supplement use of pregnant Finnish women in association with demographic variables. One thousand and seventy-five families were invited to a birth cohort study during 1998 -9. Mothers of 797 newborns completed a validated 181-item food-frequency questionnaire from which the food and nutrient intakes were calculated. The information about supplement use was collected concerning the whole pregnancy. The results of the present study suggest that healthy food choices are rather common among pregnant Finnish women and the choices are positively correlated with age and education. Nutrient supplements were used by 85 % of the women. Supplements were favoured by the older and well-educated women and by those who had normal weight before pregnancy. Of the women in the present study, 31 % received vitamin A-containing supplements, although it is not recommended during pregnancy. Taking food and supplementation into account, the intake of vitamin D did not meet the dietary recommendation and folic acid intake was below recommendation in 44 % of the women. Therefore there seemed to be unnecessary nutrient supplementation and at the same time lack of relevant supplementation among these pregnant women.

Both maternal and child's use of antibiotics were associated with an increased risk of cow's milk allergy. Future studies are needed to confirm these novel findings and to explore the potential biologic mechanisms behind the association.