Korean J Obstet Gynecol KJOG Korean Journal of Obstetrics & Gynecology 2233-5188 2233-5196 Korean Society of Obstetrics and Gynecology 10.5468/KJOG.2011.54.10.582 Original Article The effect of antenatal corticosteroid on incidence of respiratory distress syndrome according to maternal body mass index Jo Eun Ju MD Kwak Hye-Min MD Ji Hyun-Young MD Cha Hyun-Hwa MD Choi Suk-Joo MD Oh Soo-young MD Roh Cheong-Rae MD Kim Jong-Hwa MD Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Corresponding author: Suk-Joo Choi, MD. Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, Korea. Tel: +82-2-3410-3546, Fax: +82-2-3410-0630, drmaxmix.choi@samsung.com 10 2011 19 10 2011 54 10 582 590 25 05 2011 19 07 2011 09 09 2011 Copyright © 2011. Korean Society of Obstetrics and Gynecology 2011

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

 Objective

To investigate the effects of antenatal corticosteroid (ACS) on incidence of neonatal respiratory distress syndrome (RDS) according to maternal body mass index (BMI).

 Methods

We retrospectively reviewed the medical records of 715 singleton pregnant women who delivered between 24+0 and 34+0 weeks of gestation, from January 1996 to December 2006. Subjects were categorized into three groups according to ACS exposure: a nonuser group (n = 244), a single-course group (n = 377) and a multiple-course group (n = 94). Subjects were re-categorized into three groups according to maternal BMI at admission: group 1 (BMI < 23.0 kg/m2, n = 234), group 2 (BMI 23.0-24.9 kg/m2, n = 166) and group 3 (BMI ≥ 25.0 kg/m2, n = 315). Univariate and multiple logistic regression analyses were used for the statistical analysis.

 Results

Overall, the incidence of RDS was significantly lower in ACS-user groups than the non-user group, with lowest incidence in the multiple-course group (non-user vs. single-course vs. multiple-course: 44.3% vs. 41.1% vs. 11.7%, P < 0.001). The incidence of RDS was not different among the three BMI groups. Multiple logistic regression analysis showed that single- and multiple-course of ACS was significantly associated with reduced incidence of RDS: single-course, odds ratio (OR) 0.593, 95% confidence interval (CI) 0.373, 0.942; multiple-course, OR 0.085, 95% CI 0.034, 0.213. However, maternal BMI was not associated with reduced incidence of RDS with different ACS-courses (P for interaction = 0.690).

 Conclusion

ACS therapy, especially when multiple-course was used, was significantly associated with reduced incidence of RDS, but maternal BMI did not influence its effectiveness.

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Demographic characteristics of the patients and pregnancy outcomes according to antenatal steroid exposure

Bolding denotes significant findings.

Data are presented by mean ± standard deviation or number (%) or median [range].

PTL, preterm labor; IIOC, incompetent internal os of cervix; PPROM, preterm premature rupture of membranes; DM, diabetes mellitus; ACS, antenatal corticosteroid.

aJonckheere-Terpstra test, P < 0.001.

bnon-user vs. multiple-course, P < 0.05; single-course vs. multiple-course, P < 0.05.

cgestational hypertension, mild & severe preeclampsia, superimposed preeclampsia, eclampsia, chronic hypertension.

Perinatal outcomes of the preterm neonates according to antenatal steroid exposure

Bolding denotes significant findings.

Data are presented by mean ± standard deviation or number (%) or median [range].

SGA, small-for-gestational-age; NICU, neonatal intensive care unit.

aNon-user vs. multiple-course, P < 0.05; single-course vs. multiple-course, P < 0.05.

bDefined as having more than one of the following: neonatal death, respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, intraventricular hemorrhage (≥ grade 3), retinopathy of prematurity (≥ grade 3), necrotizing enterocolitis (≥ stage 2), suspected or proven early and late neonatal sepsis.

Demographic characteristics of the patients and pregnancy outcomes according to maternal body mass index

Bolding denotes significant findings.

Data are presented by mean ± standard deviation or number (%) or median [range].

PTL, preterm labor; IIOC, incompetent internal os of cervix; PPROM, preterm premature rupture of membranes; ACS, antenatal corticosteroid; DM, diabetes mellitus.

aJonckheere-Terpstra test, P < 0.05.

bNon-user vs. multiple-course, P < 0.05.

cGestational hypertension, mild & severe preeclampsia, superimposed preeclampsia, eclampsia, chronic hypertension.

Perinatal outcomes of the preterm neonates according to maternal body mass index

Bolding denotes significant findings.

Data are presented by mean ± standard deviation or number (%) or median [range].

SGA, small-for-gestational-age; NICU, neonatal intensive care unit.

aJonckheere-Terpstra test, P < 0.05.

bDefined as having more than one of the following: neonatal death, respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, intraventricular hemorrhage (≥ grade 3), retinopathy of prematurity (≥ grade 3), necrotizing enterocolitis (≥ stage 2), suspected or proven early and late neonatal sepsis.

Incidence of respiratory distress syndrome and composite morbidity according to maternal body mass index and antenatal steroid exposure

Bolding denotes significant findings.

RDS; respiratory distress syndrome,, BMI; body mass index

Relationship between the incidence of respiratory distress syndrome and independent variables analyzed by multiple logistic regression

Bolding denotes significant findings.

OR; odds ratio, CI; confidence interval, BMI; body mass index, ACS; antenatal corticosteroid.