Medicines prescribed for asthma, discontinuation and perinatal outcomes, including breastfeeding: A population cohort analysis

Abstract

Objectives To explore associations between exposures to medicines prescribed for asthma and their discontinuation in pregnancy and preterm birth [<37 or <32 weeks], SGA [<10th and <3rd centiles], and breastfeeding at 6–8 weeks. Methods Design. A population-based cohort study. Setting. The Secure Anonymised Information Linkage [SAIL] databank in Wales, linking maternal primary care data with infant outcomes. Population. 107,573, 105,331, and 38,725 infants born 2000–2010 with information on premature birth, SGA and breastfeeding respectively, after exclusions. Exposures. maternal prescriptions for asthma medicines or their discontinuation in pregnancy. Methods. Odds ratios for adverse pregnancy outcomes were calculated for the exposed versus the unexposed population, adjusted for smoking, parity, age and socio-economic status. Results Prescriptions for asthma, whether continued or discontinued during pregnancy, were associated with birth at<32 weeks’ gestation, SGA <10th centile, and no breastfeeding (aOR 1.33 [1.10–1.61], 1.10 [1.03–1.18], 0.93 [0.87–1.01]). Discontinuation of asthma medicines in pregnancy was associated with birth at<37 weeks’ and <32 weeks’ gestation (aOR 1.22 [1.06–1.41], 1.53 [1.11–2.10]). All medicines examined, except ICS and SABA prescribed alone, were associated with SGA <10th centile. Conclusions Prescription of asthma medicines before or during pregnancy was associated with higher prevalence of adverse perinatal outcomes, particularly if prescriptions were discontinued during pregnancy. Women discontinuing medicines during pregnancy could be identified from prescription records. The impact of targeting close monitoring and breastfeeding support warrants exploration.

Asthma severity and impact on perinatal outcomes: an updated systematic review and meta‐analysis

“…One of the proposed biological mechanisms linking asthma exacerbation during pregnancy and low birthweight is the reduced partial pressure of oxygen in pregnant women with an asthma exacerbation. 43 Available data on the effect of asthma medication use on perinatal outcomes are very scarce, 12,29,33,34,36 and given the size of the studies and their observational nature, the evidence on asthma medication use and adverse perinatal outcomes needs to be interpreted with caution. Two of the three studies examining the effect of oral corticosteroids use on perinatal outcomes did not provide ORs adjusted for asthma severity.…”

“…34 Nine of the 20 studies included in the present review were also included in the 2013 review mentioned above, 4,27,28,[30][31][32][33][34][35] and nine studies, most of which were large-scale studies, were published after 2012. [8][9][10][11][12]17,29,39,40 Another two studies published before 2012 which were included in the present review were not included in the 2013 review. 36,37…”

“…Fifteen studies had serious risk of bias for confounding 8,11,12,[27][28][29]31,32,[34][35][36][37][38][39][40] (Table S5), principally because studies did not adjust for maternal weight or weight gain during pregnancy. Serious risk of bias was found for deviation from exposures in two studies 9,34 and for missing data in two studies.…”

Association between preterm birth and maternal allergy considering IgE level

“…Three mechanisms by which BA might increase the risk of PTB have been proposed: maternal chronic hypoxia, smooth muscle hyperactivity, and asthma medication 4,18 . With regard to the use of asthma medication during pregnancy, there were several reports of a risk of PTB 20–22 . However, many studies report the fact that inadequate asthma treatment or management, rather than the potential risks of the medication, affects pregnancy outcomes, including PTB 4,20 .…”

“…medication during pregnancy, there were several reports of a risk of PTB. [20][21][22] However, many studies report the fact that inadequate asthma treatment or management, rather than the potential risks of the medication, affects pregnancy outcomes, including PTB. 4,20 Furthermore, the greater the severity of BA, the greater the risk of PTB.…”