Infant and Maternal Outcomes in the Pregnancies of Asthmatic Women

Abstract

We examined the relationship between infant and maternal outcomes and asthma complicating pregnancy, using historical cohort analysis of singleton live deliveries in New Jersey hospitals between 1989 and 1992 (n = 447,963). Subject mother-infant dyads were identified from linked birth certificate and maternal and newborn hospital claims data. Women with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code (493) for asthma (n = 2,289) were compared with a fourfold larger randomly selected control sample (n = 9,156) from the remaining pool of women. After controlling for the effects of important confounding variables, maternal asthma was associated with the following adverse infant outcomes: preterm infant (odds ratio [OR] = 1.36; 95% confidence interval [CI], 1.18 to 1.55), low birth weight (OR = 1. 32; 95% CI, 1.10 to 1.58), small-for-gestational age (OR = 1.26; 95% CI, 1.10 to 1.45), congenital anomalies (OR = 1.37; 95% CI, 1.12 to 1.68), and increased infant hospital length of stay (OR = 1.44; 95% CI, 1.25 to 1.65). The adverse maternal outcomes associated with maternal asthma were: pre-eclampsia (OR = 2.18; 95% CI, 1.68 to 2. 83), placenta previa (OR = 1.71; 95% CI, 1.05 to 2.79), cesarean delivery (OR = 1.62; 95% CI, 1.46 to 1.80), and increased maternal hospital length of stay (OR = 1.86; 95% CI, 1.60 to 2.15). The results emphasize the need for maternal asthma to be added to the list of conditions that increase the risk of adverse pregnancy outcomes.

Impact of maternal asthma on perinatal outcomes: a two-stage sampling cohort study

“…Our results support the findings of Demissie et al, Liu et al and Enriquez et al who reported a significant association between maternal asthma and the risk of SGA infants with relative risk estimates ranging between 1.16 and 1.20 [2,3,9]. On the other hand, our results differ from those of Perlow et al, Bracken et aland Dombrowski et alwho found no significant increased risk of SGA associated with asthma [16,17,40].…”

“…Adverse perinatal outcomes, such as a preterm birth, a low-birth-weight (LBW) infant and a small-for-gestational-age (SGA) infant, have been reported to be higher in pregnant women with asthma when compared to women without asthma in some studies [2][3][4][5][6][7][8][9][10], but not in other studies [11][12][13][14][15][16][17][18]. In a meta-analysis conducted by Murphy et al, asthmatic women with and without asthma exacerbations during pregnancy were compared to non-asthmatic women for the risk of LBW infant and preterm delivery [19].…”

Safety of leukotriene receptor antagonists in pregnancy

“…6 Slightly decreased birth weight in infants born to women who used LTRAs in our study is most likely attributable to more severe and/or poorly controlled maternal asthma in that group. Maternal asthma has been associated with an increased risk of low birth weight, [26][27][28][29] reduced mean birth weight, 28,30 and intrauterine growth restriction 6,26,31,32 (reviewed by Bakhireva et al 22 ). Moreover, relationships have been reported between reduced intrauterine growth and more severe or poorly controlled asthma, as defined by lower pulmonary function, 5 increased symptoms, 6 or exacerbations.…”

The relationship of asthma medication use to perinatal outcomes

“…1 Several studies have reported increased incidences of preeclampsia, preterm birth, or lower birth weight in infants of asthmatic compared with nonasthmatic mothers. [2][3][4][5] Two main potentially remedial mechanisms have been hypothesized to explain these observations 6 : (1) poor asthma control leading to fetal hypoxia and (2) asthma medication. There are some data to support a relationship between poor asthma control, as defined by hospitalization 7,8 or lower FEV 1 values 9 and either lower birth weight 7,8 or low ponderal indices.…”