Worth the wait? Preconception weight reduction in women and men with obesity and infertility: a narrative review

Impact of bariatric surgery, lifestyle change, and pharmacotherapy on fertility in men with obesity: a systematic review protocol

OBJECTIVE

This review will determine whether various health interventions designed to reduce weight (lifestyle change, bariatric surgery, pharmacotherapy) in men with obesity are associated with improved fertility markers. The review will also establish whether the degree of weight loss achieved through these methods is associated with improvement.

BACKGROUND

Current preconception guidelines provide limited information for men with obesity. Small studies implementing lifestyle changes in men are associated with improvement in sperm quality, whereas bariatric surgery has not been associated with improvements in sperm quality. Determining the benefit of different interventions and the relationship to weight lost is necessary to optimize male fertility.

INCLUSION CRITERIA

The population will be men < 50 years who are either overweight (BMI > 25 kg/m2) or obese (BMI > 30 kg/m2). The exposure of interest will be an intervention undertaken to improve health or reduce weight, categorized as lifestyle change, bariatric surgery, or pharmacotherapy. Outcomes will include time to conception, fecundity rate, assisted reproduction outcomes, and semen quality measures. Secondary analysis will determine whether degree of weight loss achieved is associated with degree of improvement.

METHODS

This review will follow the JBI methodology for systematic reviews of etiology and risk. Databases to be searched will include PubMed, Embase (Ovid), Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. Articles not translated into English will be excluded. Methodological quality will be assessed using the JBI critical appraisal tools. Data will be extracted using a standardized tool developed by the reviewers. Statistical meta-analysis will be performed where possible to synthesize outcomes of similar methods.

REVIEW REGISTRATION NUMBER

PROSPERO CRD 42022349665.

Association of overweight and obesity with cumulative live birth rates according to women's age: A cohort study of 26 567 treatment cycles

OBJECTIVE

To evaluate the effect of age on the association between maternal body mass index (BMI) and cumulative live birth rates (CLBRs) following in vitro fertilization treatment.

METHOD

We retrospectively analyzed the data of 26 567 women undergoing in vitro fertilization/intracytoplasmic sperm injection from 2016 to 2019. We conducted multivariate regression analysis of the association between CLBRs and maternal BMI and age category.

RESULTS

A total of 16 626 (62.58%) patients achieved a live birth. Women with obesity had significantly decreased CLBRs compared with women who had normal weight (odds ratio [OR] 0.73 [95% confidence interval (CI), 0.66-0.80]). The significant interaction between age and BMI suggested that the impact of BMI on CLBRs was moderated by women's age (P interaction <0.001). The association between obesity and CLBRs was inverse among women aged <30 years (OR, 0.63 [95% CI, 0.54-0.73]), 30 to 34 years (OR, 0.79 [95% CI, 0.67-0.93]), and 35 to 37 years (OR, 0.71 [95% CI, 0.52-0.98]); however, decreases in CLBRs with obesity were not observed in women aged 38 to 40 years (OR, 1.17 [95% CI, 0.70-1.94]) and ≥ 41 years (OR, 1.25 [95% CI, 0.53-2.96]).

CONCLUSION

Maternal obesity was significantly associated with a lower likelihood of having a live birth, but the risk differed according to women's age. A higher BMI might have a less-pronounced detrimental effect with increasing age.

Moderate and increased physical activity is not detrimental to live birth rates among women with unexplained infertility and obesity

Objective

To determine if moderate physical activity is associated with live birth rates in women with unexplained infertility and obesity.

Design

Secondary analysis of the Improving Reproductive Fitness through Pretreatment with Lifestyle Modification in Obese Women with Unexplained Infertility trial.

Setting

US fertility centers, 2015-2019.

Patients

A total of 379 women participated in Improving Reproductive Fitness through Pretreatment with Lifestyle Modification in Obese Women with Unexplained Infertility trial, a lifestyle modification program with increased physical activity (phase I, 16 weeks) and up to three cycles of clomiphene citrate treatment and intrauterine insemination (phase II).

Interventions

Participants were instructed to add 500 steps/day weekly until a maximum of 10,000 steps/day was reached and maintained. Participants were stratified as active (top third, N = 125) and less active (lower third, N = 125) on the basis of the average number of steps per day recorded using a FitBit activity tracker.

Main Outcome Measures

Live birth rate.

Results

Active participants were more physically active at the time of enrollment than less active participants (average baseline steps per day, 8,708 [7,079-10,000] vs. 4,695 [3,844-5,811]; P ≤ 0.001) and were more likely to reach 10,000 steps/day than less active participants (average steps per day, 10,526 [9,481-11,810] vs. 6,442 [4,644-7,747]; P ≤ 0.001), although both groups increased their average steps per day by a similar amount (1,818 vs.1,747; P = 0.57). There was no difference in live birth rates (24/125 [19.2%] vs. 25/125 [20%]; P = 0.87) between active and less active participants nor were there differences in clinical pregnancy rates (P = 0.45) or miscarriage rates (P = 0.49) between the two groups.

Conclusions

Active participants were more likely to achieve the physical activity goal, although this was not associated with benefit or harm with respect to live birth.

Clinical Trial Registration Number

ClinicalTrials.gov (NCT02432209), first posted: May 4, 2015.

Obesity and In Vitro Fertilization

Obesity is a highly prevalent chronic disease with a significant effect on reproductive-age women. The clinical implications of obesity on fertility and pregnancy are well studied citing ovulatory dysfunction, hormonal imbalances, higher miscarriage rates, and increased maternal and neonatal risks. For this reason, many patients with obesity seek reproductive specialists to help build their families. Despite this literature base, the effect of weight loss interventions prior to assisted reproductive technology (ART) is lacking. This review aims to outline the impact of obesity on ART, specifically in vitro fertilization (IVF). Response differences to treatment protocols compared with normal weight counterparts, limitations of access to care, and the mixed results of weight-reduction strategies prior to fertility treatment will be addressed. The known data surrounding benefits of lifestyle modification, pharmacologic therapies, and surgical interventions for obesity prior to IVF are outlined and found to emphasize a need for further research to determine the optimal approach for infertility patients with obesity.

Navigating the Role of Anti-Obesity Agents Prior to Pregnancy: A Narrative Review

Utilization of anti-obesity agents is rising in reproductive-age females with some planning for future pregnancy. Lifestyle-induced weight loss has been shown to increase spontaneous conception rate, improve rates of fertility intervention complications, and decrease pregnancy comorbidities. However, the definitive role of assisting weight loss with medication prior to pregnancy remains to be established. The implications of anti-obesity agent used prior to pregnancy are explored in this narrative review, considering benefits of weight loss as well as available evidence for use and risks of anti-obesity agents prior to pregnancy.

Fertility outcomes following bariatric surgery

Obesity impacts human health in more than one way. The influence of obesity on human reproduction and fertility has been extensively examined. Bariatric surgery (BS) has been used as an effective tool to achieve long-term weight loss in both sexes. BS improves hormonal profiling, increasing the odds of spontaneous pregnancy and success rates following assisted reproductive techniques in infertile females. For obese males, BS does improve sexual function and hormonal profile; however, conflicting reports discuss reduced sperm parameters following BS. Although the benefits of BS in the fertility field are acknowledged, many areas call for further research, like choosing the safest surgical techniques, determining the optimal timing to get pregnant, and resolving the uncertainty of sperm parameters.