Effect of overweight and obesity on assisted reproductive technology—a systematic review

Abstract

Obesity is known to be associated with sub-optimal reproductive performance but its direct effect on the outcome of assisted reproduction techniques (ART) is less clear. This present study aimed to perform a systematic review of the available evidence to assess the effects of obesity on the outcome of ART. A number of observational studies were identified. Interpretation of the results was compromised by variations in the methods used to define overweight and obese populations and inconsistencies in the choice and definition of outcome measures. Compared with women with a BMI of 25 kg/m 2 or less, women with a BMI 25 kg/m 2 have a lower chance of pregnancy following IVF [odds ratio (OR) 0.71, 95% CI: 0.62, 0.81], require higher dose of gonadotrophins (weighed mean differences 210.08, 95% CI: 149.12, 271.05) and have an increased miscarriage rate (OR 1.33, 95% CI: 1.06, 1.68). There is insufficient evidence on the effect of BMI on live birth, cycle cancellation, oocyte recovery and ovarian hyperstimulation syndrome. Further studies with clear entry criteria and uniform reporting of outcomes are needed to investigate the true impact of weight on the outcome of ART.

Association of angiogenic cytokines (VEGF-A and VEGF-C) and clinical characteristic in women with unexplained recurrent miscarriage

“…Overweight women have a higher incidence of pregnancy complication and miscarriage (39). The prevalence of obesity in infertile women is high and some studies showed that BMI was associated with RPL (40).…”

Associations between IVF outcomes and essential trace elements measured in follicular fluid and urine: a pilot study

“…Using multivariable regression approaches, we explored associations between trace elements and IVF outcomes, adjusted for confounders selected a priori based on the literature, including age (years), BMI (kg/m 2 ), race (Bother^/ BAsian^), and current or past cigarette smoking (Bnever^/ Bever^) [25][26][27][28]. Trace element data were natural logtransformed after adding a constant to accommodate negative values and zeros, as were continuous study outcomes to satisfy distributional assumptions and to stabilize variances.…”

Metabolic Syndrome and Infertility in Women

“…Consequently, obese women have been shown to require higher doses of gonadotropins and longer durations of ovarian stimulation. Higher incidence of follicular synchrony and higher cancellation rates has also been reported (55). The lower number of oocytes retrieved in obese women about normal weight women could be attributed technical difficulties or lower number of follicles (56).…”