Public Opinion Regarding Utilization of Assisted Reproductive Technology (ART) in Obese Women

Introduction

More than two-thirds of adult American women meet the criteria of the World Health Organization (WHO) for overweight or obesity. ¹ The deleterious effects of obesity on female reproduction are well recognized and include ovulatory dysfunction, infertility, miscarriage, and obstetric complications. ^2,3 Obesity has also been associated with higher gonadotropin requirements, increased cycle cancellation, and decreased pregnancy and live birth rates in women seeking assisted reproductive technologies (ART) ^{4 –7}

Concern about poor clinical outcomes and increased health risks have led to calls to restrict access to fertility treatment in women above a certain body mass index (BMI), particularly in countries where government-funded healthcare requires allocation of limited resources. ^{8 –12} Others argue that such restrictions violate the principle of patient autonomy, unjustly stigmatize obese women, and limit timely access to effective treatment. ^13,14 Opponents also cite the lack of a consistent standard as to what an appropriate BMI cutoff should be. The European Society of Human Reproduction and Embryology (ESHRE) Task Force on Ethics and Law states that more data are needed to establish whether access to ART should be made conditional upon body weight and, if so, at what limit. ¹⁵ The committee recommends that physicians encourage attempts at weight loss prior to fertility treatment but acknowledges that this should not be required of women approaching the end of their fertile period.

As the American Society of Reproductive Medicine (ASRM) currently has no similar guidelines, reproductive medicine providers in the United States are left to make individual determinations about how to best regulate their practices. Given the inconsistencies in current practice and the increasing prevalence of obesity, it is important to take into account not only the experience of the medical community but also the expectations of the general public before formulating policy on this controversial issue. The objective of this survey was to assess public opinion regarding provision of ART to obese women in the United States.

Materials and Methods

The survey was distributed using Zoomerang Online Surveys & Polls, the professional online survey-distribution service that has previously recruited more than 2 million individuals ages 18–75 from the U.S. general public. Zoomerang members are literate in English, have computer and Internet access, and have agreed to voluntarily complete online surveys in exchange for noncash incentives, including charitable donations or sweepstakes entries. In order to discourage rushing through surveys, members are limited in the number of surveys completed in a given time period. Use of this service for research purposes has been previously described in other publications. ^16,17

For this study, we requested approximately equal ratios of males and females; no other demographic parameters were specified and therefore reflect those of the Zoomerang sample population. No identifying information was collected from participants; the service tracked the total number of surveys sent out in order to reach the target goal of 1000 completed surveys. The study was approved by the Institutional Review Board/Partners Human Research Committee at Brigham and Women's Hospital.

The survey instrument was developed by the investigators and was tested on a pilot sample of individuals for clarity and ease of administration. The survey consisted of a brief introductory page with study contact information, followed by a series of 12 questions regarding the use of ART to help obese women conceive (Supplemental Fig. S1; Supplemental Data are available online at www.liebertpub.com/jwh). An additional 25 questions addressed demographic variables that may be associated with attitudes toward use of ART in obese women. Most questions were single-answer multiple choice. For questions that assessed the reasons for an individual's opinion, participants had the opportunity to select all applicable choices. The demographic section included freehand responses for participants to record height and weight. BMI was calculated as weight in kilograms divided by height in meters squared (kg/m²). BMI was categorized based on the WHO classification into underweight (<18.5 kg/m²), normal weight (18.5–24.9 kg/m²), overweight (25–29.9 kg/m²), and obese (>30 kg/m²) ranges. Reproductive age was considered 18–45, with the upper limit of 45 years selected to reflect the common practice of many fertility programs of limiting ART using autologous gametes to women under 45 years.

Descriptive statistics were used to assess the demographics of the study population. Crude (unadjusted) and multivariate (adjusted) odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression. Age, BMI, and gender were identified as significant predictors of response in unadjusted analyses and were subsequently adjusted for in multivariate models. Tests for linear trend were calculated by assigning the median value, or midpoint, of each category to all participants in the group and then calculating a Wald statistic. All reported p-values are two-sided. SAS statistical software (version 9.2) was used for all analyses.

Results

The survey was sent to a total of 1095 individuals in September 2011. Of the 1049 who completed the survey (95.8% response rate), 138 indicated disagreement with the use of in vitro fertilization (IVF) in normal-weight women and were excluded from all further analyses. These respondents were presumed to have a baseline objection to the use of IVF. The remaining 911 individuals comprised the primary study population and were included in all subsequent analyses.

Demographic characteristics of the study population are depicted in Table 1. The population comprised approximately equal numbers of men (49%) and women (51%). Fifty-one percent were above the age of 46; a majority (85%), Caucasian. Thirty-one percent of the study population were overweight based on BMI; an additional 35%, obese. More than half of participants (64%) had children of their own.

Among the 911 respondents who supported the use of IVF in normal-weight women, 30% did not support its use in obese women. Support of IVF in obese women was directly correlated with a respondent's BMI and inversely associated with a respondent's age in unadjusted analyses. In the multivariate models, age was negatively correlated with support for use of IVF in obese women (p-value, test for linear trend=0.008). The odds of supporting the use of IVF in obese women was 38% lower in individuals 46 years and older than in younger reproductive-age individuals (OR 0.62, 95% CI 0.45–0.85). BMI remained significantly associated with support of IVF in obese women (p-value, test for linear trend=0.002) in the adjusted model, with morbidly obese participants with a BMI>40 kg/m² being nearly three times as likely to support its use (OR 2.87, 95% CI 1.28–6.44). There was no statistically significant association between an individual's gender, income, education, race, profession, state of residence, or self-reported history of infertility and support of IVF in obese women.

Survey participants were presented with a number of potential reasons to either support or oppose use of ART in obese women; the most commonly selected reasons are depicted in Table 2. Among those respondents supporting the use of IVF for obese women, a majority (66%) cited patient autonomy, followed by a medical obligation to help a woman conceive regardless of body weight (48%). The primary reason for opposing IVF in obese women among respondents was a higher risk of obstetrical complications (46%), although 36% of those opposed identified obesity as a modifiable risk factor that should be addressed prior to treatment.

When asked whether obese women should be encouraged to lose weight before undergoing IVF, an overwhelming majority of respondents (85%) supported attempted weight loss before either IVF or spontaneous conception. By contrast, only 34% of survey respondents stated that obese women should be required to lose weight before proceeding with IVF. Both BMI and education level were negatively correlated with a respondent's support of requiring weight loss before IVF (p-value, test for linear trend <0.03 for both comparisons). Specifically, obese respondents with BMI>40 kg/m² were less likely to state that weight loss should be required (OR 0.38, 95% CI 0.18–0.83) as compared to normal-weight participants, as were participants with graduate-level education (OR 0.54, 95% CI 0.32–0.92) as compared to participants with a high school education or less.

Fifty-five percent of survey participants support the implementation of an upper BMI limit for access to ART services (Table 3). In multivariate models, increasing education level (p-value, test for linear trend=0.02) and BMI (p-value, test for linear trend=0.01) were inversely associated with supporting a BMI limit. Individuals who had themselves used IVF services were also less likely (OR 0.27, 95% CI 0.07–0.99) to support implementation of such a limit as compared to those who had not. There was no significant association between gender, age, income, race, state of residence, parity, or history of infertility and support of a BMI limit for access to ART. Among supporters, 14% preferred that the limit be mandated by national medical societies; 39% preferred that the specific limit be dictated by individual infertility physicians. Thirty percent of supporters indicated a preference for BMI limits to be set with input of both parties.

A sizable proportion (35%) of respondents did not support insurance coverage for IVF in any population. Forty-six percent reported support for insurance coverage for IVF services regardless of a woman's body weight, as compared to 18% who supported coverage for normal-weight women only. No demographic variables were found to be significant predictors of discordant support for insurance coverage between the two populations.

Discussion

This is the first study to assess public opinion regarding the provision of ART to obese women. The demographics of the study respondents were similar to those of the U.S. population with respect to variables, including gender, income, and body weight, with 31% of respondents being obese. A majority of survey participants supports the use of IVF in obese women, based on issues of patient autonomy and nondiscrimination in medical care, although more than half of respondents also advocated the implementation of an upper BMI limit for access to these services. Perhaps not surprisingly, respondents who themselves were of high BMI or had used IVF services in the past were less likely to support such a limit than were those of normal weight or those who had not utilized IVF services. One-third of those who supported a BMI limit indicated that the limit should be set in a cooperative manner between national medical societies and the individual infertility physicians.

A number of editorials have presented arguments both in favor of and opposition to restricting access to ART based on body weight. ^10,12,14 Proponents cite the poorer success rates of fertility treatment with increased body weight, associated obstetrical and childhood health risks, and maximizing resource allocation in countries with publicly funded healthcare. Participants in the present study were more likely to oppose the use of IVF in obese women, based on the obstetrical and pediatric health risks rather than decreased likelihood of success. Indeed, obesity has been shown to increase the relative risk of adverse obstetric outcomes, including gestational hypertension, pre-eclampsia, gestational diabetes, cesarean delivery, and fetal macrosomia. ¹⁸ Survey participants opposed to restricting IVF in obese women cited concerns regarding patient autonomy and nondiscrimination in medical care. This viewpoint is reinforced in a 2010 review by Pandey et al., who argue that the risk of complications does not typically prevent obese women from receiving other types of medical or surgical treatment. ¹⁴ The authors also state that with the increasing global prevalence of obesity, restricting access to care may eliminate infertility services from a growing majority of the eligible population. As an illustration, 65.5% of our study population reported a BMI>25.0 kg/m², reflective of the estimated two-thirds of American adults who are overweight or obese. ¹ This may be even more relevant in light of emerging data concerning the potentially detrimental impact of male BMI on fertility outcome; the few existing studies have variably demonstrated an adverse impact on blastocyst development, ¹⁹ clinical pregnancy rates after IVF, ²⁰ and live birth rates after IVF with intracytoplasmic sperm injection (ICSI). ²¹

Any discussion regarding the specifics of restricting access to infertility treatment based on BMI requires an understanding of current practices in offering treatment to obese women. A 2009 analysis by Vahratian et al. revealed that, in the United States, 42.7% of infertile women with class II or III obesity (BMI>35 kg/m²) reported receiving medical or surgical treatment as compared with 64.0% of women with class I obesity (BMI 30.0–34.9 kg/m²), 47.4% of overweight women (BI 25.0–29.9 kg/m²), and 58.9% of normal-weight women (BMI 81.5–24.9 kg/m²). ¹³ Although not statistically significant, the data suggest a disparity in infertility treatment with increasing BMI. A 2006 survey of infertility clinics in the United Kingdom revealed a large degree of variation in the clinics' practice standards for treatment of obese infertile women. Sixty-five percent of surveyed centers reported restricting access to IVF based on a woman's BMI, with the majority reporting an upper limit that ranged between 25 kg/m² and 30 kg/m². ¹¹ In 2011, Harris et al. conducted a similar survey of 43 medical directors of infertility clinics in the United States. ²² Although 82.9% of medical directors believed that a BMI cutoff should exist, only 54.8% of clinics had implemented one, with the majority employing a cutoff of 40 kg/m². It appears that, for fear of being considered discriminatory, many physicians remain reluctant to develop BMI restrictions in the absence of national policy.

Our study is the first of its kind to report the opinion of a large cross-section of men and women in the United States regarding the utilization of ART in obese women. The large sample size enabled us to conduct multivariate analyses to determine what demographic factors, if any, are associated with an individual's support or opposition. A significant limitation of the study is the inability to generalize the results to the entire U.S. population, given the inherent bias of Internet-based surveys toward English-literate individuals who have access to a computer. A second limitation is the inherent difficulty of creating a survey of public opinion regarding a medical issue in that participants must be offered sufficient introductory information about the topic to form an educated opinion but must simultaneously not be biased by the information that is given. Although we strove to ensure that our introductory paragraph regarding the impact of maternal obesity on offspring health was brief, unbiased, and easy to understand (Supplementary Fig. S1), it is possible that the results would have differed if participants had been offered different or additional information on the topic prior to completing the survey.

Conclusion

The ESHRE Task Force on Ethics and Law recommends that, because the available evidence suggests that weight loss confers a positive reproductive effect, fertility physicians should insist that a serious effort at achieving these results be made. The task force states that more data are required to establish whether assisted reproduction should be made conditional on body weight and if so, where the line should be drawn. ¹⁵ The absence of a similar guideline in the United States leaves clinics to make individual determinations about how best to regulate their practices. Results from the present Internet-based survey indicate that individuals who are in favor of ART are also likely to support its use among obese women while expressing a concurrent desire for professional oversight and regulation of these services.