Effect of body mass index on in vitro fertilization outcomes in women with polycystic ovary syndrome

Am J Obstet Gynecol. 2014 Aug;211(2):163.e1-6. doi: 10.1016/j.ajog.2014.03.035. Epub 2014 Mar 18.


Objective: The objective of the investigation was to study the effect of body mass index (BMI) on in vitro fertilization (IVF) outcomes within a polycystic ovary syndrome (PCOS) population.

Study design: This was a retrospective cohort study including 101 cycles from 79 women younger than 40 years old with a clinically documented diagnosis of PCOS by Rotterdam criteria undergoing IVF at a university-based infertility clinic from 2001 through 2010. All participants were stratified by BMI calculated from height and weight recorded within 3 months of cycle start: lean (18.7-24.9 kg/m(2), n = 51), overweight (25-29.9 kg/m(2), n = 19), and obese (≥30 kg/m(2), n = 31). Linear, logistic, and Poisson regressions were used as appropriate to estimate the effect of a range of BMIs on IVF outcomes while adjusting for potential confounders.

Results: Obese PCOS women had 69% lower odds of clinical pregnancy per cycle start (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.11-0.86; P = .02) and 77% lower odds of clinical pregnancy per embryo transfer (OR, 0.23; 95% CI, -0.08 to 0.68; P = .008) compared with lean PCOS women. Among obese PCOS women, the odds of live birth were 71% lower per cycle start (OR, 0.29; 95% CI, 0.10-0.84; P = .02) and 77% lower per embryo transfer (OR, 0.23; 95% CI, 0.07-0.71; P = .01) compared with lean PCOS women. There was a trend toward decreased ovarian hyperstimulation syndrome incidence with increasing BMI among women with PCOS: 19.6% in lean, 10.5% in overweight, and 3.2% in obese.

Conclusion: PCOS is a broad syndrome, with our results demonstrating 2 distinct populations, lean and obese, which have different IVF outcomes including ovarian hyperstimulation syndrome risk profiles. This information is important for clinicians because it informs treatment decisions.

Keywords: assisted reproduction; body mass index; in vitro fertilization; polycystic ovary syndrome; weight.

MeSH terms

  • Adult
  • Body Mass Index*
  • Cohort Studies
  • Embryo Transfer
  • Female
  • Fertilization in Vitro*
  • Humans
  • Infertility, Female / epidemiology
  • Infertility, Female / etiology
  • Infertility, Female / therapy
  • Linear Models
  • Live Birth / epidemiology*
  • Obesity / epidemiology
  • Oocyte Retrieval / statistics & numerical data
  • Ovarian Hyperstimulation Syndrome / epidemiology*
  • Polycystic Ovary Syndrome / epidemiology*
  • Pregnancy
  • Pregnancy Rate*
  • Retrospective Studies
  • Young Adult