A population-based prescription study of asthma drugs during pregnancy: changing the intensity of asthma therapy and perinatal outcomes.
BACKGROUND
Among the goals of gestational asthma, therapy is optimisation of pulmonary function. According to the US Food and Drug Administration, no asthma drugs can be considered 'safe' during pregnancy. Fear of adverse fetal effects may thus lead to restrictive use of asthma drugs during pregnancy, and no population-based studies concerning gestational asthma therapy exist.


OBJECTIVE
To examine whether asthma drugs or changing intensity of asthma therapy during pregnancy was associated with deviations from expected values of gestational age, birth weight, length at birth, or malformations.


METHODS
The Birth Registry was used to identify all 15,756 primiparous women who gave birth in the County of North Jutland between 1991 and 1996. According to the North Jutland Prescription Database, 303 of these women received prescriptions for asthma drugs during pregnancy. Women who did not purchase any prescription drugs during pregnancy constituted the reference group.


CONCLUSIONS
Women who received prescriptions for asthma drugs during pregnancy gave birth to infants with birth weight and length at birth within the expected limits. Reducing intensity of asthma treatment during pregnancy was associated with lower birth weight and length at birth. This may indicate that pregnant women chose to discontinue therapy although their disease severity justifies continuation of treatment. However, analyses did not take into account important clinical variables, and results could also be due to confounding factors or chance.
Olesen
C
C
Danish Epidemiology Science Centre, Department of Epidemiology and Social Medicine, University of Aarhus, Aarhus, Denmark. cho@soci.au.dk
Thrane
N
N
Nielsen
G L
GL
Sørensen
H T
HT
Olsen
J
J
D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome
D018927:Anti-Asthmatic Agents