Female Fertility Before and After Bariatric Surgery

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Female Fertility Before and After Bariatric Surgery


In this study, there was no overall improvement in female fertility after bariatric surgery, with a similar proportion of women, before and after surgery, who achieved pregnancy within 12 months (76.8% vs. 76.3% respectively), including women diagnosed with PCOS (38.3% vs. 38.9%).



Obese women who lose weight following bariatric surgery show some reversal of obesity related effects on female fertility and pregnancy complications, however it has also been linked to several adverse outcomes.

In women with Polycystic Ovarian Syndrome (PCOS) excess weight worsens their ovulatory dysfunction and perinatal complications with the former showing improvements following bariatric surgery.

However, each type of bariatric surgery seems to have a different effect on reproductive outcomes for reasons unknown. This makes it difficult for Doctors to give tailored advice to women of childbearing age seeking bariatric surgery.


To investigate the effect of bariatric surgery on fertility and pregnancy outcomes, in women with and without PCOS, according to surgical procedure (sleeve gastrectomy vs Roux-en-Y-gastric bypass).


A population of of 872 women who attended the National Health Service University hospital in Catalunya, Spain for bariatric surgery between 2005 and 2010 were assessed for eligibility.

After excluding women older than 39 years of age (n = 574) and those no longer contactable for follow up, 217 women were included in this study, of which 43 were diagnosed with PCOS.

Reproductive outcomes pre- and post-surgery was evaluated by telephone interview, with patient anthropometric and metabolic data already on file, from annual follow up visits post-surgery. Mean follow up period post-surgery was 10.1 years, while mean age of women during surgery was 31.9.


Initial analysis of the entire study population (n=217) revealed a significant reduction in mean BMI (body mass index) one year onwards post-surgery, from 47.1kg/mto 28.9kg/m2. This improvement in BMI was still significantly lower 10 years later at 32.1kg/m2.

Unsurprisingly regular menstrual cycles also improved from 52.9% to 72.9%, one year post surgery for the entire group, along with a significant reduction in common comorbidities (type 2 diabetes, hypertension, obstructive sleep apnoea).

Next, analysis of reproductive outcomes for the entire group showed the proportion of women, with a time to pregnancy less than or greater than 12 months, did not change significantly post-surgery.

On the other hand, the proportion of women who achieved at least one pregnancy was significantly higher in the preoperative period (47.9% vs 37.3%) culminating in a higher mean number of live-births per couple pre-surgery (0.74 vs 0.40) compared to post-surgery. However, the rate of macrosomia in newborns did decrease significantly from 21.4% to 2.2% post-surgery.

Bariatric surgery
Bariatric surgery
Number of patients11293
Regular menstrual cycles54.2%79.5%
Irregular menstrual cycles38.3%15.9%
Under hormonal treatment7.5%4.5%
Time to pregnancy < 1 year76.8%76.3%
Time to pregnancy > 1 year23.2%23.7%
Mean no. pregnancies per couple1.030.54
Mean no. live-births per couple0.740.40
Mean no. spontaneous miscarriages0.290.15
Delivery at term89.2%86.0%
Mean birth weight (grams)32933078
Before and after bariatric surgery outcomes of only patients seeking pregnancy

Next, advanced (IPTW) analysis of anthropometric and reproductive data found that a higher proportion of patients, who underwent laparoscopic sleeve gastrectomy (LSG), had a time to pregnancy greater than 12 months post-surgery.

Time to pregnancy < 1 year39.7%26.6%
Time to pregnancy > 1 year7.1%17.8%
No desire53.2%53.2%
Post-surgery outcomes for the entire group according to surgical procedure

Similar (IPTW) analysis of PCOS and non-PCOS women confirmed that irregular menstrual cycles was more prevalent among women with PCOS (56.3% vs. 35.3%) pre-surgery. However this improved significantly post-surgery down to a similar rate as non-PCOS women (13.0% vs. 15.1%).

Interestingly when analysing reproductive outcomes between the 2 groups, no statistically significant differences were found (P>0.2). 

Time to pregnancy < 1 year31.7%38.9%
Time to pregnancy > 1 year11.1%9.7%
No desire57.2%51.4%
Post-surgery outcomes for the entire group according to PCOS diagnosis

Although the mean number of miscarriages per couple, was significantly higher pre-surgery for women with PCOS.

Pre-surgey miscarriages0.250.45
Post-surgery miscarriages0.150.13
Mean number of miscarriages per couple before and after surgery according to PCOS diagnosis

Further studies are now required to determine if different bariatric surgical techniques impact the reproductive health of women long term.


  1. Self-reporting of information via survey.


No external funding was declared for this study.


Proportional measurements of the human body.

Inverse Probability of the Treatment Weights.

Larger than average newborn (≥4000 g).

Period of time from birth of baby up to 1 years of age.

Similar studies

Benito E, et al. (2020). Fertility and pregnancy outcomes in women with polycystic ovary syndrome following bariatric surgery. https://doi.org/10.1210/clinem/dgaa439

Kominiarek M A, et al. (2017). American Society for Metabolic and Bariatric Surgery position statement on the impact of obesity and obesity treatment on fertility and fertility therapy Endorsed by the American College of Obstetricians and Gynecologists and the Obesity Society. https://doi.org/10.1016/j.soard.2017.02.006

Butterworth J, et al. (2016). Bariatric Surgery, polycystic ovary syndrome, and infertility. https://doi.org/10.1155/2016/1871594

Edison E, et al. (2016). Bariatric surgery in obese women of reproductive age improves conditions that underlie fertility and pregnancy outcomes: retrospective cohort study of UK National Bariatric Surgery Registry (NBSR). https://doi.org/10.1007/s11695-016-2202-4


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