Talk:Abnormal Development - Maternal Obesity
Maternal overweight and obesity in early pregnancy and risk of infant mortality: a population based cohort study in Sweden
Stefan Johansson, Eduardo Villamor, Maria Altman, Anna-Karin Edstedt Bonamy, Fredrik Granath, Sven Cnattingius
Objective To investigate associations between maternal overweight and obesity and infant mortality outcomes, including cause-specific mortality.
Design Population based cohort study.
Setting and participants 1 857 822 live single births in Sweden 1992–2010.
Main outcome measures Associations between maternal body mass index (BMI) in early pregnancy and risks of infant, neonatal, and postneonatal mortality, overall and stratified by gestational length and by causes of infant death. Odds ratios were adjusted for maternal age, parity, smoking, education, height, country of birth, and year of delivery.
Results Infant mortality rates increased from 2.4/1000 among normal weight women (BMI 18.5–24.9) to 5.8/1000 among women with obesity grade 3 (BMI ≥40.0). Compared with normal weight, overweight (BMI 25.0–29.9) and obesity grade 1 (BMI 30.0–34.9) were associated with modestly increased risks of infant mortality (adjusted odds ratios 1.25 (95% confidence interval 1.16 to 1.35) and 1.37 (1.22 to 1.53), respectively), and obesity grade 2 (BMI 35.0–39.9) and grade 3 were associated with more than doubled risks (adjusted odds ratios 2.11 (1.79 to 2.49) and 2.44 (1.88 to 3.17)). In analyses stratified by preterm and term births, maternal BMI was related to risks of infant mortality primarily in term births (≥37 weeks), where risks of deaths due to birth asphyxia and other neonatal morbidities increased with maternal overweight and obesity. Obesity grade 2–3 was also associated with increased infant mortality due to congenital anomalies and sudden infant death syndrome.
Conclusions Maternal overweight and obesity are associated with increased risks of infant mortality due to increased mortality risk in term births and an increased prevalence of preterm births. Maternal overweight and obesity may be an important preventable risk factor for infant mortality in many countries.
BMJ 2014; 349 doi: http://dx.doi.org/10.1136/bmj.g6572 (Published 02 December 2014) Cite this as: BMJ 2014;349:g6572
The double burden household in sub-Saharan Africa: maternal overweight and obesity and childhood undernutrition from the year 2000: results from World Health Organization Data (WHO) and Demographic Health Surveys (DHS)
BMC Public Health. 2014 Oct 31;14(1):1124. doi: 10.1186/1471-2458-14-1124.
BACKGROUND: Previous studies have characterized an increasing trend of double burden households, or households with individuals experiencing both undernutrition and obesity, in countries undergoing a nutrition transition. Although most prior studies indicate the prevalence of double burden households is highest in middle-income countries, there is some support for an increase in double burden households in sub-Saharan African countries as well. METHOD: Using data from the Demographic Health Surveys (DHS) and the World Health Organization (WHO), the prevalence of double burden households in sub-Saharan African countries was calculated and the associations between prevalence of overweight/obese adults and underweight, stunted and wasted children were evaluated at the country and household (DHS only) levels. Restricted analyses and frequencies were calculated using urban-only datasets. Surveys from 28 African countries were available using WHO data and 26 from the DHS surveys. Only surveys that were conducted after 2000 were included in analyses. RESULTS: Using the WHO datasets, there were inverse associations between the prevalence of overweight and obesity in adults and underweight, stunting and wasting in children. Correspondingly, there were positive associations between adult underweight and child underweight, stunting and wasting. These associations were not significant in a smaller sample size using urban-only surveys. The prevalence of double burden households in DHS datasets was low: under 5 percent for obese mothers and underweight, stunted or wasted child pairs with a slightly higher percentage for overweight mothers and children with undernutrition. Restricting the analysis to urban only populations did not increase the frequencies of double burden households significantly. CONCLUSION: There was a low prevalence of double burden households in recent data from sub-Saharan Africa. Countries that have a high prevalence of child undernutrition correspondingly have a high prevalence of adult underweight and low prevalence of adult overweight and obesity.
PLoS Med. 2014 May 20;11(5):e1001648. doi: 10.1371/journal.pmed.1001648. eCollection 2014.
Persson M1, Johansson S1, Villamor E2, Cnattingius S1.
BACKGROUND: Maternal overweight and obesity increase risks of pregnancy and delivery complications and neonatal mortality, but the mechanisms are unclear. The objective of the study was to investigate associations between maternal body mass index (BMI) in early pregnancy and severe asphyxia-related outcomes in infants delivered at term (≥37 weeks). METHODS AND FINDINGS: A nation-wide Swedish cohort study based on data from the Medical Birth Register included all live singleton term births in Sweden between 1992 and 2010. Logistic regression analyses were used to obtain odds ratios (ORs) with 95% CIs for Apgar scores between 0 and 3 at 5 and 10 minutes, meconium aspiration syndrome, and neonatal seizures, adjusted for maternal height, maternal age, parity, mother's smoking habits, education, country of birth, and year of infant birth. Among 1,764,403 term births, 86% had data on early pregnancy BMI and Apgar scores. There were 1,380 infants who had Apgar score 0-3 at 5 minutes (absolute risk = 0.8 per 1,000) and 894 had Apgar score 0-3 at 10 minutes (absolute risk = 0.5 per 1,000). Compared with infants of mothers with normal BMI (18.5-24.9), the adjusted ORs (95% CI) for Apgar scores 0-3 at 10 minutes were as follows: BMI 25-29.9: 1.32 (1.10-1.58); BMI 30-34.9: 1.57 (1.20-2.07); BMI 35-39.9: 1.80 (1.15-2.82); and BMI ≥40: 3.41 (1.91-6.09). The ORs for Apgar scores 0-3 at 5 minutes, meconium aspiration, and neonatal seizures increased similarly with maternal BMI. A study limitation was lack of data on effects of obstetric interventions and neonatal resuscitation efforts. CONCLUSION: Risks of severe asphyxia-related outcomes in term infants increase with maternal overweight and obesity. Given the high prevalence of the exposure and the severity of the outcomes studied, the results are of potential public health relevance and should be confirmed in other populations. Prevention of overweight and obesity in women of reproductive age is important to improve perinatal health.
Maternal obesity and risk of preterm delivery
JAMA. 2013 Jun 12;309(22):2362-70. doi: 10.1001/jama.2013.6295.
Cnattingius S1, Villamor E, Johansson S, Edstedt Bonamy AK, Persson M, Wikström AK, Granath F.
Abstract IMPORTANCE: Preterm birth is a leading cause of infant mortality, morbidity, and long-term disability, and these risks increase with decreasing gestational age. Obesity increases the risk of preterm delivery, but the associations between overweight and obesity and subtypes of preterm delivery are not clear. OBJECTIVE: To study the associations between early pregnancy body mass index (BMI) and risk of preterm delivery by gestational age and by precursors of preterm delivery. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study of women with live singleton births in Sweden from 1992 through 2010. Maternal and pregnancy characteristics were obtained from the nationwide Swedish Medical Birth Register. MAIN OUTCOMES AND MEASURES: Risks of preterm deliveries (extremely, 22-27 weeks; very, 28-31 weeks; and moderately, 32-36 weeks). These outcomes were further characterized as spontaneous (related to preterm contractions or preterm premature rupture of membranes) and medically indicated preterm delivery (cesarean delivery before onset of labor or induced onset of labor). Risk estimates were adjusted for maternal age, parity, smoking, education, height, mother's country of birth, and year of delivery. RESULTS: Among 1,599,551 deliveries with information on early pregnancy BMI, 3082 were extremely preterm, 6893 were very preterm, and 67,059 were moderately preterm. Risks of extremely, very, and moderately preterm deliveries increased with BMI and the overweight and obesity-related risks were highest for extremely preterm delivery. Among normal-weight women (BMI 18.5-<25), the rate of extremely preterm delivery was 0.17%. As compared with normal-weight women, rates (%) and adjusted odds ratios (ORs [95% CIs]) of extremely preterm delivery were as follows: BMI 25 to less than 30 (0.21%; OR, 1.26; 95% CI, 1.15-1.37), BMI 30 to less than 35 (0.27%; OR, 1.58; 95% CI, 1.39-1.79), BMI 35 to less than 40 (0.35%; OR, 2.01; 95% CI, 1.66-2.45), and BMI of 40 or greater (0.52%; OR, 2.99; 95% CI, 2.28-3.92). Risk of spontaneous extremely preterm delivery increased with BMI among obese women (BMI≥30). Risks of medically indicated preterm deliveries increased with BMI among overweight and obese women. CONCLUSIONS AND RELEVANCE: In Sweden, maternal overweight and obesity during pregnancy were associated with increased risks of preterm delivery, especially extremely preterm delivery. These associations should be assessed in other populations. Comment in Obesity: effect of maternal obesity on neonatal outcomes. [Nat Rev Endocrinol. 2013] Maternal obesity is an independent risk factor for spontaneous extremely preterm delivery. [Evid Based Med. 2014]