Inflammation during pregnancy linked to asthma in offspring
Many risk factors influence risk of asthma and allergies, including ones that begin before birth, during pregnancy. C-reactive protein (CRP) is a marker of systemic inflammation that, during pregnancy, may be associated with increased risk of asthma and allergies in offspring.
In The Journal of Allergy and Clinical Immunology: In Practice, Chen et al report on a study that measured CRP in blood samples from 522 pregnant women at two time points: 10-18 weeks gestation and 32-38 weeks gestation. All women were participants in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized controlled trial of high compared to low dose vitamin D supplementation during pregnancy for prevention of asthma in offspring. After pregnancy, offspring of the women participating in the study were followed through age 6 years, with assessment every 3 months for development of asthma and environmental allergy blood tests at age 6 years.
Chen et al found that childhood asthma was most common among offspring of mothers who had high CRP at either time point during pregnancy, or an increase in CRP from early to late pregnancy. The link between maternal CRP and asthma was strongest among children who also had positive allergy tests. CRP is a general marker of inflammation. There were several maternal characteristics and exposures that were associated with higher CRP levels in pregnancy. Some of these were low socio-economic status, maternal obesity prior to pregnancy, a diet rich in processed foods, exposure to cigarette smoke, gestational diabetes, and vitamin D insufficiency. Attention to some of the modifiable exposures during pregnancy could help in lowering the state of inflammation. Some of these include eating a healthy diet, avoiding exposure to cigarette smoke (either personal smoking or exposure to smoke from household members who smoke), getting adequate prenatal care to test for and manage gestational diabetes, and ensuring adequate vitamin D intake during pregnancy. These findings need to be validated in other cohorts and future studies are needed to determine how to most effectively reduce inflammation during pregnancy to optimize maternal and child health.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.