L M Sorbye1,2, K Klungsoyr3,4, O Samdal2, K M Owe5,6, N-H Morken3,7. 1. Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway. 2. Department of Health Promotion and Development, Faculty of Psychology, University of Bergen, Bergen, Norway. 3. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. 4. Medical Birth Registry of Norway, Norwegian Institute of Public Health, Bergen, Norway. 5. Norwegian National Advisory Unit on Women's Health, Oslo University Hospital, Rikshospitalet, Oslo, Norway. 6. Department of Psychosomatics and Health Behaviour, Norwegian Institute of Public Health, Oslo, Norway. 7. Department of Clinical Sciences, University of Bergen, Bergen, Norway.
Abstract
OBJECTIVE: To examine the effect of maternal pre-pregnant body mass index (BMI) and recreational physical activity on perinatal mortality. DESIGN: A prospective cohort study. SETTING: The Norwegian Mother and Child Cohort (MoBa), 1999-2008. POPULATION: Singleton pregnancies without congenital anomalies (n = 77 246). METHODS: Pre-pregnant BMI was classified as underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (30-34.9) or morbidly obese (BMI ≥ 35). Risk estimates were obtained by logistic regression and adjusted for confounders. MAIN OUTCOME MEASURES: Perinatal death (stillbirth ≥ 22 weeks plus early neonatal death 0-7 days after birth). RESULTS: An increased risk of perinatal death was seen in obese [odds ratio (OR) 2.4, 95% CI (confidence interval) 1.7-3.4] and morbidly obese women (OR 3.3, 95% CI 2.1-5.1) as compared with normal weight women. In the group participating in recreational physical activity during pregnancy, obese women had an OR of 3.2 (95% CI 2.2-4.7) for perinatal death relative to non-obese women. In the non-active group the corresponding OR was 1.8 (95% CI 1.1-2.8) for obese women compared with non-obese women. The difference in perinatal mortality risk related to obesity between the active and non-active groups was statistically significant (P-value for interaction = 0.046, multiplicative model). CONCLUSIONS: Maternal obesity was associated with a two- to three-fold increased risk of perinatal death when compared with normal weight. For women with a BMI <30 the lowest perinatal mortality was seen in those performing recreational physical activity at least once a week.
OBJECTIVE: To examine the effect of maternal pre-pregnant body mass index (BMI) and recreational physical activity on perinatal mortality. DESIGN: A prospective cohort study. SETTING: The Norwegian Mother and Child Cohort (MoBa), 1999-2008. POPULATION: Singleton pregnancies without congenital anomalies (n = 77 246). METHODS: Pre-pregnant BMI was classified as underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (30-34.9) or morbidly obese (BMI ≥ 35). Risk estimates were obtained by logistic regression and adjusted for confounders. MAIN OUTCOME MEASURES: Perinatal death (stillbirth ≥ 22 weeks plus early neonatal death 0-7 days after birth). RESULTS: An increased risk of perinatal death was seen in obese [odds ratio (OR) 2.4, 95% CI (confidence interval) 1.7-3.4] and morbidly obesewomen (OR 3.3, 95% CI 2.1-5.1) as compared with normal weight women. In the group participating in recreational physical activity during pregnancy, obesewomen had an OR of 3.2 (95% CI 2.2-4.7) for perinatal death relative to non-obesewomen. In the non-active group the corresponding OR was 1.8 (95% CI 1.1-2.8) for obesewomen compared with non-obesewomen. The difference in perinatal mortality risk related to obesity between the active and non-active groups was statistically significant (P-value for interaction = 0.046, multiplicative model). CONCLUSIONS:Maternal obesity was associated with a two- to three-fold increased risk of perinatal death when compared with normal weight. For women with a BMI <30 the lowest perinatal mortality was seen in those performing recreational physical activity at least once a week.
Authors: Hilde B Lauritzen; Tricia L Larose; Torbjørn Øien; Torkjel M Sandanger; Jon Ø Odland; Margot van de Bor; Geir W Jacobsen Journal: Environ Health Date: 2018-01-18 Impact factor: 5.984