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There is an epidemic of obesity among women and men of reproductive age.
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Numerous epidemiologic and translational studies demonstrate adverse effects of obesity on various stages of the reproductive process, although the underlying mechanisms are largely unknown.
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Of all the evidence linking obesity to adverse reproductive function and outcomes, the most concerning is the evidence demonstrating links between preconceptional maternal obesity and long-term disease in the offspring.
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Weight loss
Obesity and Reproductive Function
Section snippets
Key points
Measuring obesity and reproductive risk
Disentangling the individual components of obesity associated with poor health outcomes is difficult.1, 2 Body mass index (BMI), calculated as the weight in kilograms divided by the height in meters squared, or overall body size adjusted for height, is obviously, the most accessible measure of obesity because tools for measuring BMI are readily available. On the other hand, adiposity (regional or total body fat), adipokine production, and lifestyle components may also contribute individually or
The Central Nervous System (CNS)
As mentioned previously, obese women exhibit decreased LH pulse amplitude and decreased excretion of progesterone metabolites.12 In addition to causing anovulation, abnormal LH pulsatility may affect ovarian follicular steroidogenesis, leading to abnormal oocyte recruitment and poor oocyte quality and/or altered endometrial development, and it could affect the function of the corpus luteum in the luteal phase. How decreased LH pulse amplitude specifically affects subsequent reproductive
An Opportunity for Intervention
Obesity-related anovulation and subfertility may provide an important opportunity for preconceptional intervention and improvements in reproductive function and outcomes. These opportunities go beyond interventions for obesity because they include opportunities to screen for pregestational diabetes mellitus and optimization of glucose control in women who are diabetic, opportunities to screen for preconceptional rubella and varicella vaccination, counseling regarding healthy diet and lifestyle
Competing risks in the setting of infertility: obesity versus age
As discussed, for obese women with infertility, weight loss may offer improved fertility. On the other hand, after the age of 35 years, there may be less of an effect of obesity on fertility rates with IVF,108, 109 although the obstetric risks that obesity poses remain. Furthermore, after the age of 35 years, there is a decrease in success of IVF in all women undergoing IVF, regardless of the infertility diagnosis or BMI.109 These issues make for a difficult clinical scenario because age and
Fertility treatment of obese women
Numerous studies have demonstrated decreased efficacy of fertility treatments in obese women.33, 43 As a result, some centers offering fertility treatments have put BMI limits on who they will treat and what types of treatment they will offer. In fact, in New Zealand, where fertility treatments are covered under the national health care plan, there is a BMI cutoff of 32 kg/m2 that limits access to IVF. In the United States, some fertility treatment centers have BMI restrictions; however, these
The need for transdisciplinary research and novel approaches
The authors propose that obesity research as it relates to reproduction requires a transdisciplinary approach because both obesity and reproduction are complex systems affected by social, environmental, biologic, economic, and genetic influences to name a few. Tackling the problem of reproduction in obese women will require cooperative efforts among experts in all these fields of study. Ultimately, this type of research may help inform models of shared decision making in which physicians and
Summary
There are many components of obesity that may affect the different steps of the reproductive process leading to adverse reproductive outcomes. Clearly, there is good data demonstrating that weight loss improves ovulatory function in obese women and improves pregnancy outcomes. On the other hand, female fertility is limited by time, the reproductive phenotype of obesity is variable, and current measures of obesity are not reliable predictors of these phenotypes. Because of the complex nature of
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2023, Fertility and SterilityPreconception hemoglobin A1c concentration in healthy women is not associated with fecundability or pregnancy loss
2022, F and S ReportsCitation Excerpt :In contrast, a study in patients with PCOS undergoing IVF found that impaired glucose tolerance using an OGTT, but not isolated impaired fasting glucose, was associated with a lower rate of conception than in those with normoglycemia (12). Based on these limited data, coupled with our findings that increasing A1c in the normal range was not associated with reduced fecundability after BMI adjustment, the glycemic status may not be an important marker for fecundability independent of the well-known impact of obesity (22, 23). Increasing A1c concentration was associated with a nonsignificant reduction in early pregnancy loss, as our loss rates per A1c tertile were relatively similar with 24.5%, 25.1%, and 20.1% for tertiles 1, 2, and 3, respectively, and are consistent with previously published loss rates in healthy populations (9).
The association of maternal pre-pregnancy Body Mass Index and gestational weight gain with pregnancy and neonatal outcomes
2024, Irish Journal of Medical Science
Disclosures: This work was supported by grant K12HD063086 from the National Institutes of Health (NIH), Bethesda, Maryland. The contents of this work are the responsibility of the authors and do not necessarily represent the official views of the NIH.