Prioritising for fertility treatments-should a high BMI exclude treatment?

Effect of weight loss before in vitro fertilization in women with obesity or overweight and infertility: a systematic review and meta-analysis

The effect of weight loss before in vitro fertilization (IVF) procedures on pregnancy outcomes in women with overweight or obesity and infertility remains controversial. In this systematic review and meta-analysis, we investigated whether weight loss before IVF in these women affected the IVF results and reproductive outcomes. PubMed, Embase, and the Cochrane Library databases were searched from the inception dates until December 2022, using combinations of relevant keywords. Only six randomized controlled trials, including 1627 women with obesity or overweight, were analyzed. The weight change in the intensive care group, compared to the control group who underwent IVF without weight loss was - 4.62 kg (mean difference; 95% confidence interval [CI] - 8.10, - 1.14). Weight loss before IVF did not significantly increase the live birth rate in women with obesity or overweight and infertility (odds ratio, 1.38; 95% CI 0.88, 2.10). The clinical pregnancy, miscarriage, ongoing pregnancy, and ectopic pregnancy rates did not differ between the weight loss and control groups before IVF. This meta-analysis demonstrated that even significant weight loss before IVF in women with obesity or overweight and infertility did not improve the live birth, clinical pregnancy, ongoing pregnancy, or ectopic pregnancy rates. PROSPERO Registration Number: CRD42023455800.

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.

Effects of preconception lifestyle intervention in infertile women with obesity: The FIT-PLESE randomized controlled trial

BACKGROUND

Women with obesity and infertility are counseled to lose weight prior to conception and infertility treatment to improve pregnancy rates and birth outcomes, although confirmatory evidence from randomized trials is lacking. We assessed whether a preconception intensive lifestyle intervention with acute weight loss is superior to a weight neutral intervention at achieving a healthy live birth.

METHODS AND FINDINGS

In this open-label, randomized controlled study (FIT-PLESE), 379 women with obesity (BMI ≥ 30 kg/m2) and unexplained infertility were randomly assigned in a 1:1 ratio to 2 preconception lifestyle modification groups lasting 16 weeks, between July 2015 and July 2018 (final follow-up September 2019) followed by infertility therapy. The primary outcome was the healthy live birth (term infant of normal weight without major anomalies) incidence. This was conducted at 9 academic health centers across the United States. The intensive group underwent increased physical activity and weight loss (target 7%) through meal replacements and medication (Orlistat) compared to a standard group with increased physical activity alone without weight loss. This was followed by standardized empiric infertility treatment consisting of 3 cycles of ovarian stimulation/intrauterine insemination. Outcomes of any resulting pregnancy were tracked. Among 191 women randomized to standard lifestyle group, 40 dropped out of the study before conception; among 188 women randomized to intensive lifestyle group, 31 dropped out of the study before conception. All the randomized women were included in the intent-to-treat analysis for primary outcome of a healthy live birth. There were no significant differences in the incidence of healthy live births [standard 29/191(15.2%), intensive 23/188(12.2%), rate ratio 0.81 (0.48 to 1.34), P = 0.40]. Intensive had significant weight loss compared to standard (-6.6 ± 5.4% versus -0.3 ± 3.2%, P < 0.001). There were improvements in metabolic health, including a marked decrease in incidence of the metabolic syndrome (baseline to 16 weeks: standard: 53.6% to 49.4%, intensive 52.8% to 32.2%, P = 0.003). Gastrointestinal side effects were significantly more common in intensive. There was a higher, but nonsignificant, first trimester pregnancy loss in the intensive group (33.3% versus 23.7% in standard, 95% rate ratio 1.40, 95% confidence interval [CI]: 0.79 to 2.50). The main limitations of the study are the limited power of the study to detect rare complications and the design difficulty in finding an adequate time matched control intervention, as the standard exercise intervention may have potentially been helpful or harmful.

CONCLUSIONS

A preconception intensive lifestyle intervention for weight loss did not improve fertility or birth outcomes compared to an exercise intervention without targeted weight loss. Improvement in metabolic health may not translate into improved female fecundity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02432209.

Effect of Excessive Body Weight and Psoriasis in Women Undergoing ICSI Procedure and State of Health of the Newborn

Excessive body weight and some concomitant diseases, such as psoriasis, accompany women treated due to infertility by intracytoplasmic sperm injection (ICSI). This study is aimed to assess effect of obesity and psoriasis on quality of egg cells, embryos, course of pregnancy, and state of a newborn after treatment with ICSI. A total of 140 women were included into the study (110 healthy women and 30 with psoriasis). Among healthy women, BMI negatively correlated with total recovery rate, total oocyte score, blastocyst formation rate (BFR) and amount and quality of blastocysts (r < 0, p < 0.001). The relationships were similar in psoriasis, however apart from average blastocyst quality (p = 0.17) and BFR (p = 0.352). In healthy patients, BMI negatively correlated with gestational age at delivery (r = −0.444, p = 0.010) and APGAR (r = −0.481, p = 0.005). An excess of adipose tissue exerts an unfavourable effect on female reproductive functions, especially with a simultaneous burden of psoriasis. Excessive body weight is conducive to development of gestational diabetes and shortens the duration of pregnancy. The burden of psoriasis in combination with excessive body weight has an impact on the risk of occurrence of intrauterine growth restriction of foetus. Overweight and obesity negatively affect the state of a newborn, measured using APGAR scale.

Efficacy of an Internet-Based Intervention to Promote a Healthy Lifestyle on the Reproductive Parameters of Overweight and Obese Women: Study Protocol for a Randomised Controlled Trial

Background: Infertility is estimated to affect 15% of couples of reproductive age. Weight management problems (being obese or overweight) are among the problems that produce infertility, both in women seeking spontaneous pregnancy and in those undergoing assisted reproduction techniques. Over the last few decades, the prevalence of obesity has increased alarmingly in our society and is now considered one of the most important public health problems. The combination of diet and exercise to achieve weight loss are currently considered an effective intervention for the improvement of reproductive parameters in overweight or obese infertile women. In other population groups, it has been shown that Internet-based interventions are just as effective as traditional ones, and these cover a larger population with a good cost–benefit ratio. However, to the best of our knowledge, no studies so far have analysed any specific online interventions for this group of infertile women. Thus, the objective of this project will be to evaluate the effectiveness of an online program to promote a healthy lifestyle among women who are overweight or obese who also have a diagnosis of infertility and are on the waiting list for in vitro fertilisation treatment. Methods: This will be a randomised controlled clinical trial conducted in 94 women which will compare a self-administered Internet-based intervention promoting a healthy lifestyle in terms of diet and exercise (n = 47) to a control group that will receive standard medical care. The online program will comprise nine modules, will last for 3 months, and will be monitored every 3 months after the intervention until the final follow-up at 12 months. The main outcome will be the spontaneous pregnancy rate. Secondary outcomes will include changes in body composition, dietary and physical exercise habits, glycaemic profiles, lipid profiles, hormonal profiles, and patient quality of life related to their fertility problems. The data analysis will be done on an intention-to-treat basis. Discussion: The aim of this study is to increase our knowledge of the effectiveness of online interventions specifically adapted to infertile women who are overweight or obese in the promotion of healthy lifestyles.

Impact of Women Obesity and Obesity Severity on Live Birth Rate after In Vitro Fertilization

Access to in vitro fertilization (IVF) for obese women varies across centers, and the impact of obesity on IVF outcomes is widely discussed. We assessed the impact of obesity and its severity on live birth rate (LBR) after IVF. We included women treated for IVF in our center. Data were prospectively collected in the BabySentry^TM software. LBR per cycle and cumulative LBR including all attempts of the couple were calculated, considering transfer of both fresh and frozen embryos. Of 1588 included women (2379 controlled ovarian stimulations), 70.2%, 19.5%, 7.9%, and 2.4% were normal-weight, overweight, class I obesity, and class II/III obesity, respectively. For each cycle, LBR did not differ according to BMI category. Adjusted odds ratios (95% confidence intervals) for obtaining a live birth at the first cycle were 1.11 (0.78–1.58) for overweight, 1.17 (0.70–1.95) for class I obese, and 1.05 (0.48–2.31) for class II/III obese women, as compared with normal-weight women. Similarly, no significant associations were found at cycles 2, 3, and 4. Cumulative LBR increased with the number of cycles, independently of the BMI class (p log-rank = 0.91). After adjustment, obesity status did not impact significantly the miscarriage rate, regardless of the cycle. In conclusion, neither women obesity nor its severity impacted the cumulative LBR after IVF.

Obesity and Reproduction

OBJECTIVE

To provide a comprehensive review and evidence-based recommendations for the delivery of fertility care to women with obesity.

OUTCOMES

The impact of obesity on fertility, fertility treatments, and both short and long-term maternal fetal outcomes was carefully considered.

EVIDENCE

Published literature was reviewed through searches of MEDLINE and CINAHL using appropriate vocabulary and key words. Results included systematic reviews, clinical trials, observational studies, clinical practice guidelines, and expert opinions.

VALUES

The Canadian Fertility & Andrology Society (CFAS) is a multidisciplinary, national non-profit society that serves as the voice of reproductive specialists, scientists, and allied health professionals working in the field of assisted reproduction in Canada. The evidence obtained for this guideline was reviewed and evaluated by the Clinical Practice Guideline (CPG) Committee of the CFAS under the leadership of the principal authors.

BENEFITS, HARMS, AND COSTS

The implementation of these recommendations should assist clinicians and other health care providers in counselling and providing reproductive care to women with obesity.

VALIDATION

This guideline and its recommendations have been reviewed and approved by the membership, the CPG Committee and the Board of Directors of the CFAS.

SPONSORS

Canadian Fertility & Andrology Society.

RECOMMENDATIONS

Twenty-one evidence based recommendations are provided. These recommendations specifically evaluate the impact of obesity on natural fertility, fertility treatments, and maternal-fetal outcomes. Strategies to lose weight and BMI cut-offs are also addressed.

Recent advances in understanding the relationship between long- and short-term weight change and fertility

The impact of excess body weight on fertility is well recognized among both women attempting to conceive spontaneously and those attempting to conceive with medical assistance. Although many leading societies of reproductive medicine have proposed weight loss as a means to counteract the negative consequences of obesity on fertility, there is limited research on this topic. In this review, we provide a brief overview of the recent advances in the literature focused on how long- and short-term weight change affects fertility among women. Overall, despite initial hope that weight loss may be beneficial for fertility, two large well-conducted randomized controlled trials have consistently shown that short-term weight loss among overweight and obese women undergoing infertility treatment does not improve a woman's probability of live birth. The observational evidence among women attempting to conceive without medical assistance also suggests limited benefits of weight loss on fecundity or pregnancy loss. In contrast, substantial weight gain between consecutive pregnancies, in the year prior to pregnancy attempt, and throughout adulthood appears to be harmful for not only time to pregnancy but also pregnancy maintenance. Future research focused on efforts to prevent weight gain during adulthood is needed to better understand whether these types of interventions may have beneficial effects on fertility.

Neutral effect of body mass index on implantation rate after frozen-thawed blastocyst transfer

OBJECTIVE

To examine the effects of body mass index (BMI) on implantation rate after uniform protocol frozen-thawed blastocyst transfer in women with a homogenous uterine environment.

DESIGN

Retrospective cohort study.

SETTING

Single IVF clinic at a large academic institution.

PATIENT(S)

Four hundred sixty-one infertile women treated at a large academic institution from January 2007 to January 2014.

INTERVENTION(S)

All women underwent standardized slow frozen-thawed blastocyst transfers with good-quality day 5-6 embryos, following an identical hormonal uterine preparation, with comparison groups divided according to BMI category: underweight (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight (25.0-29.9 kg/m²), and obese (≥30.0 kg/m²).

MAIN OUTCOME MEASURE(S)

Implantation rate.

RESULT(S)

There were no statistically significant differences identified when comparing implantation rates among the four BMI cohorts. The implantation rate was 38.2% in normal weight patients, 41.7% in underweight patients, 45.1% in overweight patients, and 34.7% in obese patients. Adjusted odds ratios (OR) demonstrated no association between the main outcome, implantation rate, and BMI. Compared with the normal weight patients, the adjusted OR of implantation was 1.70 (95% confidence interval [CI], 0.40-7.72) for underweight patients, 1.61 (95% CI, 0.97-2.68) for overweight patients, and 0.92 (95% CI, 0.49-1.72) for obese patients. Secondary outcomes, including rates of miscarriage, clinical pregnancy, ongoing pregnancy, and live birth, were not significantly different between cohorts. While powered to detect a 16% difference between overweight and normal weight women, the study was underpowered to detect differences in the underweight and obese women, and no definitive conclusions can be drawn for these small cohorts. Patients with transfers that required the longest amount of time, greater than 200 seconds, had the highest average BMI of 27.5 kg/m².

CONCLUSION(S)

Under highly controlled circumstances across 7 years of data from a single institution, using a uniform uterine preparation, following a precise transfer technique with high-quality day 5-6 slow frozen-thawed blastocysts, a BMI in the overweight range of 25-29.9 kg/m² is not associated with a poorer implantation rate or live-birth rate, nor is it associated with an increased risk of miscarriage when compared with a normal BMI range. The increased length of time required during transfer for women with higher BMI suggests body habitus may contribute to difficult transfers, although this may not translate into poorer implantation rates. By using a standardized protocol for slow freezing and thawing of embryos, using identical hormonal preparation and a uniform ET protocol, a homogenous uterine environment was created in this carefully selected cohort of women, thereby minimizing confounders and uniquely highlighting the neutral effect of overweight BMI on implantation rate.

PCOSMIC: a multi-centre randomized trial in women with PolyCystic Ovary Syndrome evaluating Metformin for Infertility with Clomiphene

BACKGROUND

Ovulation induction treatment with metformin, either alone or in combination with clomiphene citrate (CC), remains controversial even though previous randomized trials have examined this.

METHODS

A double blinded multi-centre randomized trial was undertaken including 171 women with anovulatory or oligo-ovulatory polycystic ovary syndrome. Women with high body mass index (BMI) > 32 kg/m(2) received placebo ('standard care') or metformin; women with BMI < or = 32 kg/m(2) received CC ('standard care'), metformin or both. Treatment continued for 6 months or until pregnancy was confirmed. Primary outcomes were clinical pregnancy and live birth.

RESULTS

For women with BMI > 32 kg/m(2), clinical pregnancy and live birth rates were 22% (7/32) and 16% (5/32) with metformin, 15% (5/33) and 6% (2/33) with placebo. For women with BMI < or = 32 kg/m(2), clinical pregnancy and live birth rates were 40% (14/35) and 29% (10/35) with metformin, 39% (14/36) and 36% (13/36) with CC, 54% (19/35) and 43% (15/35) with combination metformin plus CC.

CONCLUSIONS

There is no evidence that adding metformin to 'standard care' is beneficial. Pregnancy and live birth rates are low in women with BMI > 32 kg/m(2) whatever treatment is used, with no evidence of benefit of metformin over placebo. For women with BMI < or = 32 kg/m(2) there is no evidence of significant differences in outcomes whether treated with metformin, CC or both. ClinicalTrials.gov number NCT00795808; trial protocol accepted for publication November 2005: Johnson, Aust N Z Journal Obstet Gynaecol 2006;46:141-145.

Should access to fertility treatment be determined by female body mass index?

Resource allocation towards fertility treatment has been extensively debated in countries where fertility treatment is publicly-funded. Medical, social and ethical aspects have been evaluated prior to allocation of resources. Analysis of cost-effectiveness, risks and benefits and poor success rates have led to calls of restricting fertility treatment to obese women. In this debate article, we critically appraise the evidence underlying this issue and highlight the problems with such a policy. Poor success rate of treatment is unsubstantiated as there is insufficient evidence to link high body mass index (BMI) to reduction in live birth. Obstetric complications have a linear relationship with BMI but are significantly influenced by maternal age. The same is true for miscarriage rates which are influenced by the confounding factors of polycystic ovary syndrome and age. Studies have shown that the direct costs per live birth are no greater for overweight and obese women. With changing demographics over half the reproductive-age population is overweight or obese. Restricting fertility treatment on the grounds of BMI would cause stigmatization and lead to inequity, feelings of injustice and social tension as affluent women manage to bypass these draconian restrictions. Time lost and poor success of conventional weight loss strategies would jeopardize the chances of conception for many women.

Should access to fertility-related services be conditional on body mass index?

Guidelines for the clinical management of obese, reproductive age women with reduced fertility in the USA are limited. Clinical professional organizations have yet to publish practice guidelines on this topic. Thus, treatment decisions are made at the provider and/or clinic level and the variation in clinic policy regarding fertility treatment for obese women is not readily available. Globally, there is an ongoing discussion among reproductive endocrinologists that practice in countries with government-funded health care about whether treatment should be restricted to women under a certain body mass index. Our analysis of a representative US population identified that differences exist in the utilization of fertility-related services according to female body mass. Women with class II/III obesity were the group reporting the highest percentage seeking medical attention to become pregnant, but the lowest percentage receiving medical or surgical fertility-related services, although these differences were not statistically significant. As the prevalence of obesity among women of reproductive age increases both in the USA and abroad, it is critical to consider the medical, social and ethical issues involved in allocating resources for fertility treatment. Ongoing monitoring of trends in service utilization in light of the obesity epidemic and delayed childbearing will provide further insight into this clinical health policy issue.

Impact of obesity on female fertility and fertility treatment

Obesity and overweight are common conditions that have consequences not only on general health but also to a great extent on reproductive health. There is a high prevalence of obese women in the infertile population and numerous studies have highlighted the link between obesity and infertility. Obesity contributes to anovulation and menstrual irregularities, reduced conception rate and a reduced response to fertility treatment. It also increases miscarriage and contributes to maternal and perinatal complication. Reduction of obesity, particularly abdominal obesity, is associated with improvements in reproductive functions; hence, treatment of obesity itself should be the initial aim in obese infertile women before embarking on ovulation-induction drugs or assisted reproductive techniques. While various strategies for weight reduction, including diet, exercise, pharmacological and surgical intervention exist, lifestyle modification continues to be of paramount importance.

Reproductive endocrinology and clinical aspects of obesity in women

Obesity is a growing worldwide problem and is associated with a wide range of adverse effects on the female reproductive system. The endocrinological changes in obesity that may cause these adverse effects are complex and include changes in circulating adipokines and sex steroids as well as insulin resistance. Considerable evidence suggests an adverse effect of obesity on the risk of miscarriage and other maternal and fetal complications. Obese patients are also more prone to infertility. The most important single method to improve reproductive performance in obese women is weight loss that can be achieved with lifestyle changes and diet. Antiobesity drugs may also be used and, in severe cases, bariatric surgery.