The three major specialist journals carry articles on obesity and pregnancy this month. The definitions are; a BMI over 25 is overweight, over 30 obese, over 35 grossly obese, and over 40 morbidly obese.
The BJOG (Heslehurst 2007;114:187-94) traces maternal obesity over the last 15 years which shows the incidence has increased from 10% to 16% and, if the trend continues, by 2010 the rate will be 22%. This carries implications for hospital staff, facilities and special clinics all requiring more resources.
Some of those requirements will be far more caesarean sections. Bergholt et al (AJOG 2007;196:163-5) tracked a group of uncomplicated primipara and worked out their chances of an emergency CS in labour. Taking women with a BMI of less than 25 as controls, CS rates rose with BMI with those who were grossly obese having four times the risk of a CS. Failure to progress and suspected fetal distress were the main indications while one-quarter of the remaining women had an instrumental delivery.
The authors advise telling women with raised BMIs about their increased risk of CS delivery. Clinicians and patients should be aware of these statistics and share them with labour ward staff.
In the US, more than half of women of reproductive age are overweight and 30% are obese. The lower the socio-economic status, the greater the incidence of obesity. There is a spread of related problems which Catalano (Obstets Gynecol 2007;109:419-33) iterates sequentially: greater risk of miscarriage and congenital abnormalities, later manifestations of the metabolic syndrome including diabetes, cardiac dysfunction, proteinuria, sleep apnoea and fatty-liver disease, greater risk of caesarean section with anaesthetic difficulties, operative challenges, wound disruption or infection and clotting risks. Fetal risks in the short-term are macrosomia and obesity with related poorer outcomes plus long-term consequences in adolescence and adulthood of the metabolic syndrome.
