Maternal complications associated with both high and low BMI during pregnancy

According to a new study led by researchers at the Universities of Edinburgh and Aberdeen, pregnant women who have a body mass index too low or too high are more likely to have maternal complications and to require additional medical services and higher medical costs. The study was published in the BJOG : An International Journal of Obstetrics and Gynaecology and was conducted in collaboration with the Information Services Division of NHS Scotland .

Mike Marsh, BJOG deputy editor -in- chief, said that maternal obesity during pregnancy is a major cause of ill health that increases the risk of hypertension and gestational diabetes. Marsh emphasized that it is important for women to maintain their body weight before conception in order to reduce the risk of future complications of pregnancy. The researchers came to these results after they investigated more than 100,000 obstetric records in Scotland, in the period 2003-2010. They focused on BMI of pregnant women, maternal complications, the number and length of hospital stay and costs.

According to BMI, pregnant women included in the study were divided into 5 groups : underweight, BMI less than 18.5, normal weight, BMI 18.5-24.9 , overweight , BMI 25-29.9 , obese, BMI over 35. When they analyzed the BMI of pregnant women and maternal complications, researchers found that the risk increases with BMI compared to women with normal BMI. It seems that severely obese women had three times higher risk of hypertension and gestational diabetes.

The researchers also found that medical costs were higher. Compared with women with normal BMI, all other categories had an increase regarding the duration and number of hospital admissions. There is a significant difference in terms of underweight women and overweight or obese women: the first had a risk of 8% in terms of hospitalization, while women who were overweight, obese or severely obese had a risk of 16%, 45% and, respectively 88%. Dr Fiona Denison co- author of the paper, noted that the study shows that both women with low BMI and women with higher BMI  have an increased risk of complications during pregnancy, a greater number and a longer duration of hospitalization and higher medical costs.

According to Dr Denison, these results highlight the need for local and national governments in Scotland and other developed countries to implement basic strategies to help reduce the prevalence of obesity. Dr Denison added that long-term benefits of reducing maternal obesity will lead to improvements not only in the maternal and child health outcomes but also in terms of maternity costs.