WLS Can Improve Fertility

A report by the Royal College of Obstetricians and Gynaecologists (RCOG) in the UK has found that bariatric surgery can improve fertility. The report entitled, ‘The Role of Bariatric Surgery in Improving Reproductive Health’, examined the safety and effectiveness of bariatric or weight loss surgery as a way of improving female fertility and reproductive health in obese women, and concluded that bariatric surgery improves a woman’s fertility and reduce pregnancy complications. This new report is the second report from the RCOG on the role of bariatric surgery on female fertility, the first edition was called The Role of Bariatric Surgery in the Management of Female Fertility (2010).

Roger Ackroyd

“We welcome the RCOG report which has valuable insights and we agree entirely that bariatric surgery is indeed often beneficial to overweight women wishing to become pregnant,” said Mr Roger Ackroyd, President of the British Obesity and Metabolic Surgery Society. “Not only does it increase fertility in women who are often less fertile due to their weight and/or polycystic ovaries, but it can decrease problems and complications of pregnancy and in the newborn. NICE Guidelines now recommend surgery down to a BMI30 in patients with Type 2 diabetes which may include many women of child-bearing age.”

It is known that obesity has a negative impact on natural conception, miscarriage, pregnancy and the long term health of the mother and child due to an increased rate of birth defects, pregnancy complications and the possibility of disease later in life. Furthermore, obesity is a common problem among women of reproductive age with 26 percent of women in the UK reported to have a BMI>30. In addition, women are three times as likely to be admitted to hospital with a primary diagnosis of obesity as men and female patients outnumber male patients seeking bariatric surgery by a ratio of around 3:12 – approximately 70% of these women are of childbearing age. Indeed, one study found that 25% (29/115) of women presenting for bariatric surgery suffered from infertility.

However, research has suggested that bariatric surgery does improve female fertility, including an improvement in symptoms of polycystic ovary syndrome (PCOS) which influences fertility, the release of eggs, hormonal changes, sexual activity and libido. In addition, surgery can also reduce pregnancy complications when compared to untreated obese women or previous pregnancies in the same women, including a reduced risk of miscarriage, gestational diabetes, hypertension, macrosomia (large baby) and congenital abnormalities.

This latest paper reviews the most recent evidence on the safety and efficacy of bariatric surgery as an intervention to improve female fertility and reproductive outcomes in obese women.

Conception after bariatric surgery

The paper states that although the effect of bariatric surgery on fertility has been reported in a small number of papers, they do suggest that bariatric surgery improves the markers of PCOS which influence fertility, including anovulation, hirsutism, hormonal changes, insulin resistance, sexual activity and libido.

For example, a cross-sectional study of 16 obese women who underwent bariatric surgery (6 LAGB, 10 RYGB) demonstrated improvement in luteal function, although not to the same level as the 14 normal weight subjects to which they were compared. Additional studies that measured changes in ovulatory function following bariatric surgery over a longer time frame (24 months), found that surgery resulted in a shortening of the follicular phase length, which has been proposed to represent a normalising of menstrual regularity, as was improvement in female sexual function as measured by the Female Sexual Function Index.

In an Italian study of 110 young Italian women (who were previously unsuccessful at becoming pregnant) 60 conceived after postoperative weight loss with the amount of weight lost (a weight loss of greater than 5kg, p=0.01) and the BMI achieved at time of conception (p=0.01) predictive of becoming pregnant, and not the type of surgery.

Bariatric surgery also showed improvements with regard to assisted conception, although the authors of that study highlighted a possible increased risk of ovarian hyperstimulation syndrome, which can lead to ascites and significant morbidity. In addition, it is also recommended that women wait for at least a year after surgery before attempting to become pregnant. Therefore, it is recommended that all patients are given contraceptive advice before and after surgery and are advised against becoming pregnant during the initial weight loss phase, and consideration should be given to non-oral contraception, given that there may be reduced absorption of oral hormonal preparations, post-surgery.

With regards to miscarriage post-surgery, the report sate that there is little evidence, although “given that prepregnancy obesity and excessive gestational weight gain increase miscarriage rates, it is likely that bariatric surgery should result in a reduced risk of miscarriage.”

It is also recommended that post-operative bariatric patients are treated as a specialist obstetric population with specific needs and should be given intensive dietetic support, preferably by dieticians with experience of managing the nutritional complications of bariatric surgery, and closely monitored for nutritional deficiencies with supplementation given as required. In all patients regardless of surgery type, monitoring of ferritin, vitamins A, D, B1, B12 and K1, and folate should be carried out.

The paper states that in pregnant patients, surgical complications can be missed and mistaken for medical complications of pregnancy. Therefore, the potential causes of abdominal pain in pregnancy in women who have undergone bariatric surgery need to be wider than usual and include, for example, band slippage or erosion, bowel herniation or intussusception.

Neonates and infants

The paper states that whether surgery improves maternal and foetal outcomes following bariatric surgery is debatable, as one study (‘Surgically induced inter pregnancy weight loss and prevalence of overweight and obesity in offspring’) showed increased obesity rates in those born after rather than before surgery.

The paper does state that the “potential adverse effects of bariatric surgery need to be balanced against the evident improvement in overall maternal health, the improvement in conception rate, and the potentially reduced risk of obesity and metabolic illness in the offspring,” and urges addition research to differentiate between outcomes after different types of surgical interventions.

“The extent to which different types of surgery differ in efficacy and adverse effects on pregnancy, or long-term risk of obesity and cardiometabolic disease in the offspring needs further investigation, in light of their different mechanisms of action…” the paper concludes. “…The long-term outcomes of offspring of women undergoing bariatric surgery should also be examined. A more personalised approach to the choice of bariatric surgery and the timing of subsequent pregnancies as part of the management of fertility and female reproduction should be implemented. This might be guided by understanding how different surgical approaches impinge on or alter reproductive outcomes.”

To access this paper, please click here