Early fetal origins of respiratory disease supported
MedWire News: Early fetal growth is linked to lung function and the development of respiratory disorders in childhood, and maternal vitamin E intake may play a role in the association, study results suggest.
Previous research has indicated that fetal growth and events that occur in fetal life may influence lung function and the development of respiratory disease in childhood and adulthood, explain Stephen Turner (University of Aberdeen, UK) and colleagues.
They add that other studies “have reported associations between maternal vitamin E intake and fetal growth, indicating that an association between vitamin E and respiratory outcomes may be mediated by fetal size and/or growth.”
To investigate further, the researchers studied 1924 children whose mothers were recruited during the first trimester of pregnancy. Ultrasound scans were used to measure fetal crown-rump length (CRL) in the first trimester and fetal femur length (FL) and biparietal diameter (BPD) in the second trimester. Maternal plasma levels of α-tocopherol (vitamin E) were assessed at the time of the first trimester scan.
Parental questionnaires on asthma and wheeze were completed when the children were aged 5 years. The children also underwent lung function testing (spirometry) at this age.
Overall, reliable data on CRL, BPD, and FL were available for 903, 1560, and 1544 children, respectively, and questionnaire and reliable spirometry data at the age of 5 years were available for 1187 and 608 children, respectively.
After accounting for maternal smoking, gestational age, and other confounding factors, the researchers found that each mm increase in fetal CRL at the time of the first trimester scan was associated with a 4% reduced risk for ever having suffered from wheeze, and a 5% reduced risk for asthma by the age of 5 years.
Furthermore, each mm increase in fetal CRL was associated with a 5 ml increase in FEV1, a 6 ml increase in forced vital capacity (FVC), and a 0.008 ml/s increase in forced expiratory flow at between 25% and 75% of FVC at the age of 5 years.
Fetal CRL was significantly and positively associated with maternal plasma α-tocopherol.
Fetal BPD and FL in the second trimester were also inversely associated with the risk for wheeze and asthma at the age of 5 years, but only BPD was positively associated with spirometric indices.
Turner and team conclude in the journal Thorax: “The level of lung function and predisposition to asthma symptoms may be determined in the first trimester, and maternal vitamin E status appears relevant to this association.”
They add: “We believe that there is now sufficient evidence to undertake intervention studies whereby maternal diets during pregnancy are either supplemented or modified to optimize vitamin E intake to recommended levels of intake.”
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By Mark Cowen