How should women be advised on weight management in pregnancy?
BMJ 2012; 344 doi: https://doi.org/10.1136/bmj.e2774 (Published 17 May 2012) Cite this as: BMJ 2012;344:e2774
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Whereas maternal obesity increases the risk of pregnancy complications including miscarriage, foetal abnormality, hypertension, diabetes, thrombosis, difficulty in delivery leading to higher caesarean rates, and infection [1-4], rates of adverse maternal and neonatal outcomes are lower in women who become pregnant following bariatric surgery [4,5]. Although women are generally advised to avoid pregnancy for 12 – 24 months after bariatric surgery due to fears of foetal under-nutrition and reduced weight loss benefits [3,4], little is known of the effect of gestation on weight loss outcomes.
We identified 232 women of childbearing age (18 – 45 years) from an automated database that included 730 obese people who had undergone bariatric surgery at our institution. Mean ± standard deviation (s.d.) age was 34.0 ± 5.9 years, pre-operative weight 137.7 ± 21.3 kg and body mass index (BMI; the weight in kilograms divided by the square of the height in metres) 50.6 ± 7.2 kg/m2. One-hundred and ninety-seven women (84.9%) had undergone Roux-en-Y gastric bypass surgery, 19 (8.2%) adjustable gastric banding, eight (3.4%) sleeve gastrectomy and eight (3.4%) other procedures.
Twenty-one women became pregnant following bariatric surgery. They were younger at the time of surgery compared to women in the non-pregnancy group with mean ± s.d. age of 28.0 ± 5.4 vs. 34.6 ± 5.6 years, respectively (P < 0.001). The two groups were otherwise well matched in pre-operative weight (136.5 ± 18.5 vs. 137.8 ± 21.6 kg, non-significant (ns)), BMI (49.2 ± 7.4 vs. 50.7 ± 7.2 kg/m2, ns) and type of bariatric procedure. The time to first pregnancy was a median 11 (range, 1.5 – 36) months following bariatric surgery and was planned in six women (28.6%). Eighteen women (86%) completed pregnancy successfully; live birth was achieved by vaginal route in 12 (57%) and caesarean section in six (29%); two women (9%) undertook medical termination of pregnancy and one (5%) suffered a spontaneous miscarriage.
Both groups of women achieved significant weight loss after bariatric surgery (Figure 1). Women in the pregnancy group lost 70.4% of excess weight (the difference of pre-operative weight and ideal body weight based on a BMI of 25 kg/m2) compared to 70.0% in the non-pregnancy group at median 30 months of follow-up (ns).
We conclude that pregnancy after bariatric surgery in women of childbearing age is safe and does not adversely influence weight loss outcomes. However, close surveillance of maternal weight and nutritional status is advisable, particularly if conception occurs in the first 12 months following bariatric surgery.
Aderinsola Alatishe medical student
Basil J. Ammori consultant laparoscopic bariatric surgeon and honorary professor of surgery
Akheel A. Syed consultant endocrinologist and honorary senior lecturer
Salford Royal NHS Foundation Trust and University Teaching Hospital, Salford, Greater Manchester M6 8HD and The University of Manchester, Oxford Road, Manchester M13 9PL
aas@drsyed.org
Acknowledgements
Permission was obtained from the Caldicott Guardian of our institution.
References
1. Poston L, Chappell LC. How should women be advised on weight management in pregnancy? BMJ 2012;344:e2774.
2. Centre for Maternal and Child Enquiries (CMACE). Maternal obesity in the UK: Findings from a national project. London: CMACE, 2010.
3. American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 105: Bariatric surgery and pregnancy. Obstet Gynecol 2009;113(6):1405-13.
4. Wax JR. Risks and management of obesity in pregnancy: current controversies. Curr Opin Obstet Gynecol 2009;21(2):117-23.
5. Maggard MA, Yermilov I, Li Z, Maglione M, Newberry S, Suttorp M, et al. Pregnancy and fertility following bariatric surgery: a systematic review. JAMA 2008;300(19):2286-96.
Figure
Figure 1. Weight loss outcomes in pregnancy and non-pregnancy groups of women of childbearing age following bariatric surgery. Excess weight was the difference of the pre-operative body weight and the ideal body weight needed to achieve the reference standard body mass index of 25 kg/m2. Error bars represent standard error of the mean.
Competing interests: No competing interests
Poston and Chappell's editorial focusses on the challenges of modifying obesity in pregnant women with the aim of improving end points relating to events up to and including delivery. They also draw our attention to the sobering statistic that more than half the women of reproductive age in the United Kingdom are overweight or obese. Therefore, as well as trying to improve pregnancy outcome for obese women, we must also take this opportunity to tackle obesity itself by introducing long term life skills in healthy eating and exercise.
Antenatal care has a broad and holistic role, including the opportunity to optimise maternal wellbeing beyond delivery, increasing the potential for women to lead healthier and longer lives. A well known example of this is the aim for women who have developed gestational diabetes to continue, beyond the puerperium, the exercise and dietary advice learnt during pregnancy in order to reduce their high chance of subsequent type 2 diabetes. Ideally future research into obesity in pregnancy should also include follow up of the woman as well as the child, to determine the longterm impact of the interventions on maternal obesity.
Competing interests: No competing interests
Re: How should women be advised on weight management in pregnancy?
Alatishe and colleagues (10 September 2012) make a valuable contribution to this important topic of fertility and bariatric surgery. Their data supports the conclusions of recent systematic reviews [1,2]:
1. 5-15% of women of childbearing age who undergo bariatric surgery will get pregnant in the postoperative follow-up period [1].
2. Obstetric complications in these women are less common than in matched obese female controls [1,2].
What we do need to know is how many of their large cohort reported reduced fecundity preoperatively, particularly when over 70% of postoperative pregnancies are reported as unplanned. This will help to quantify the effect of bariatric surgery on female fertility (current evidence for which is lacking in volume and statistical power) and may well highlight areas for improvement in their local family planning services.
References
1. Scholtz S, Le Roux C, Balen AH. The role of bariatric surgery in the management of female infertility. Hum Fertil (Camb), 2010;12(2): 67-71.
2. Dalfra, MG, Busetto, L, Chilelli, NC, Lapolla, A. Pregnancy and foetal outcome after bariatric surgery: a review of recent studies. J Matern Fetal Neonatal Med 2012; 25(9): 1537.
Competing interests: No competing interests