Multiple maternal and perinatal factors linked to asthma risk in children
MedWire News: Maternal asthma, cesarean section, maternal age, and birth weight are just some of the maternal and perinatal factors independently associated with asthma risk in children, research shows.
“There is much interest in the possibility that perinatal factors may influence the risk of disease in later life,” explain Michael Goldacre (University of Oxford, UK) and team in the journal BMC Pulmonary Medicine.
To investigate maternal and perinatal factors associated with asthma risk in children, the researchers studied data from the Oxford record linkage study on 248,612 children who were born between 1970 and 1989.
The team compared the birth and medical records of 4017 children who were hospitalized for asthma by 1999 with those of the remaining 244,595 who were not.
A separate analysis was conducted among children who were first admitted before the age of 2 years, as a diagnosis of asthma made in this age group is sometimes less certain than one made in older children.
Of the 4017 children hospitalized for asthma, 13.3% were first admitted before the age of 2 years, 69.5% between 2 and 10 years-of-age, and 17.2% at the age of 11 or older. Overall, 62.6% of those hospitalized for asthma were males.
Multivariate analysis revealed that maternal asthma (odds ratio [OR]= 3.1), male gender (OR=1.8), a low birthweight of less than 3 kg (OR=1.2), maternal smoking (OR=1.1), and cesarean section delivery (OR=1.2) were significant independent risk factors for asthma-related hospitalization among the children.
In children aged less than 2 years, having at least one older sibling (OR=1.3) and a gestation period of 37 weeks or less (OR=1.6) were also significant independent risk factors for asthma-related hospitalizations.
In children aged over 6 years , having a mother aged under 25 years or over 35 years at delivery was associated with a 1.16- and 1.40-fold, respectively, increased risk for asthma-related hospitalization compared with having a mother aged 25–35 years at birth. Higher social class appeared to be protective against hospitalization for asthma in this age group.
The researchers also note that hospital admissions for asthma were more common in males than females in early childhood, whereas females were more likely than males to be hospitalized for the disease in teenage years.
Goldacre and team conclude: “Our study adds to the evidence that the following factors have significant and independent effects on the risk of asthma: maternal asthma, male sex in childhood, low birth weight and short gestational age, maternal smoking, delivery by caesarean section, and having older siblings.”
They add: “The study also demonstrates the utility of using routinely collected health data, with data linkage, for studying potential perinatal risk factors for diseases in the child.”
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By Mark Cowen