Asthma and pregnancy: a prospective study of 198 pregnancies.

A study was designed to investigate whether asthma, when carefully managed, is associated with an increased risk of complications in connection with pregnancy. One hundred and eighty one asthmatic women were monitored during 198 pregnancies. Antiasthmatic treatment consisted of inhaled beta 2 adrenergic drugs, beclomethasone, sodium cromoglycate, oral theophylline, and systemic corticosteroids as needed. Postpartum information on asthmatic symptoms and infant feeding was collected by means of a questionnaire. A control group of 198 non-asthmatic pregnant women was matched for age and parity. Atopic women had less severe asthma than non-atopic women. During pregnancy 40% of the patients were managed with the same antiasthmatic medication as before pregnancy; 18% needed less and 42% more medication. Pre-eclampsia occurred more often in asthmatic than control subjects, especially in patients with severe asthma. Hypoglycaemia occurred more often in infants of mothers with severe asthma than in infants of mothers with less severe disease. Theophylline medication at term did not influence labour or delivery. Asthma caused no emergencies during labour. Among the asthmatic subjects 28% of babies were delivered by caesarean section compared with 17% in the control group. There was no difference between asthmatic and control subjects with regard to length of gestation, birth weight, incidence of perinatal deaths, low Apgar scores, neonatal respiratory difficulties, hyperbilirubinaemia, or malformations. It is concluded that severe asthma or systemic corticosteroid treatment (or both) during pregnancy seems to increase the incidence of mild pre-eclampsia in the mother and hypoglycaemia in the infant. The findings suggest that careful supervision of asthma during pregnancy and labour by obstetricians and chest physicians working in close collaboration should prevent most of the serious obstetric and neonatal complications of asthma in pregnancy reported by previous authors.