May 2008 Research on Obesity and its Effects Among Irish Expectant Mothers

Professor John Morrison and his group at NUI Galway have recently published a report pertaining to the incidence of obesity among pregnant Irish women, and the impact it has on their capability to deliver their infants by normal delivery. This study involved a close analysis of 5162 women who delivered their infants at Galway University Hospital. It included both women in their first pregnancy, and those in subsequent pregnancies. The body mass index (BMI) of all women was measured and compared with their outcome in terms of having a normal vaginal delivery, an assisted normal vaginal delivery (using forceps or vacuum) or an emergency caesarean section. According to Professor John Morrison, NUI Galway, "There is emerging evidence in the medical literature that obesity is becoming a major health problem in numerous developed countries. Yet, until now, there has been no published data in relation to obesity and pregnancy in an Irish obstetric population." The women were classified into five international categories: underweight; normal weight; overweight; obese; and morbidly obese. The primary aim of the study was to evaluate the incidence of the categories of overweight, obese and morbidly obese women in this Irish population, and secondly to see what effect it had on their success in having a normal delivery. A remarkably high (48.2%) of women attending the maternity hospital among this group of 5162 women, were either overweight (BMI 26.0 -29.9), or obese (BMI > 30), including morbidly obese (overweight 22.8%; obese 19.8% and morbidly obese 5.6%). By international classification, 2.6% of women attending the maternity hospital of this group were underweight and 49.2% were of normal weight. The levels of obesity were marginally lower in first time mothers, in comparison to women in subsequent pregnancies. Morbid obesity (BMI > 35), occurred in 5.6% of the women overall and in 4.3% of first time mothers and 6.5% of women in subsequent pregnancies. Professor Morrison continued, "These levels of overweight and obesity are significantly high when compared with the international literature. This level of obesity in pregnancy exerts a significant impact on maternal health, on fetal wellbeing and on ultimate delivery, and these issues are clearly discussed in the publication, in an Irish healthcare context". The second aspect of the study investigated the outcome in relation to the mode of delivery for women who were obese, in comparison to women who were of normal weight. For women in their first pregnancy who were of normal weight, the vaginal delivery rate was 83.1% but for obese primigravida this rate was as low as 55.3%. In other words, obesity conferred a two to three fold increase risk of delivery by emergency caesarean section for both women in their first pregnancy, and those in their subsequent pregnancy. Professor Morrison concluded, "These findings have major implications for health care in Ireland. Obesity in pregnancy has important implications for both maternal wellbeing being during the pregnancy, maternal health long term, infant health and chronic disorders in adulthood." One of the conclusions from this study was that obese women in their first pregnancy should be clearly counselled about the 30% risk of emergency caesarean section in pregnancy. -ends-