© Springer Science+Business Media New York 2015
Emily S. Jungheim (ed.)Obesity and Fertility10.1007/978-1-4939-2611-4_1111. Obesity, Reproductive Outcomes, and Access to Infertility Treatments: A Clinical and Ethical Debate
(1)
Department of Reproductive Endocrinology and Infertility, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
(2)
Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
Keywords
ObesityInfertilityAccessFertility treatmentsIn vitro fertilizationBiomedical ethicsIntroduction
The obesity epidemic has significantly impacted risks in obstetrics and gynecology. Pregnancy-related complications in obese pregnant women include increased risk of fetal anomalies, gestational diabetes mellitus, stillbirth, fetal macrosomia, and Cesarean delivery. Obese women also have unique challenges to fertility and fecundity such as increased risk of early miscarriage compared to normal-weight women [1]. Obesity is associated with disordered ovulation and menstrual cycle irregularity, most notably in women with polycystic ovary syndrome (PCOS) which affects 5–10 % of reproductive-age women [2, 3]. While overweight or obese status is not a requisite for the diagnosis of PCOS, 50–75 % of affected individuals are overweight or obese [2, 4] Anovulation is the primary defect leading to infertility in obese women with PCOS.
As with normal-weight women, the treatment of infertility in overweight and obese women must be individualized to maternal factors, paternal factors, and risks and benefits of various treatments. Numerous clinical reports have demonstrated that infertility treatments (regardless of the underlying cause) in overweight and obese women result in lower odds of live birth than in normal-weight women. A major finding of the Cooperative Multicenter Reproductive Medicine Network Trial of Clomiphene, Metformin, or Both for Infertility in the Polycystic Ovary Syndrome was that subjects with a body mass index (BMI) greater than 30 kg/m2 had a significantly lower rate of live birth than those with BMI less than 30 kg/m2 independent of assigned treatment (clomiphene citrate, metformin, or the treatments combined) [5]. The risk of early pregnancy loss has also been shown to be greater in obese women who conceive with fertility treatments compared to nonobese women [2]. Modest weight loss—between 5 and 10 % of total body weight—restores ovulatory cycles in many oligoovulatory women with PCOS [6]. In addition, significant weight loss as occurs with bariatric surgery, drastically reduces perinatal complications that often occur in the pregnancies of obese women [2]. Despite concerns about risks to fetal growth and development following surgical weight loss, pregnancies conceived at least 12 months following bariatric procedures have not been associated with significant perinatal morbidity [7, 8].
Assisted reproductive technologies (ART) such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are often recommended to women with specific infertility diagnoses (i.e., tubal factor, severe oligospermia) or to those who have not achieved a pregnancy with treatments such as ovulation induction or artificial insemination. Obesity has been noted to negatively impact multiple facets of ART such as response to gonadotropins, cycle cancellation rates, clinical pregnancy rates, and live birth rates [9, 10]. Obesity may also diminish live birth rates in IVF when donor oocytes are used and the recipient is obese [11], however, the literature has not consistently supported this association [12].
These data support the fact that obesity challenges fecundity in both natural and assisted attempts at conception. In light of the diminished efficacy of ART in obese women using autologous oocytes, the specific risks of treatment (i.e., ovarian hyperstimulation syndrome, egg retrieval procedure, and conception of multiples) and the known benefits of weight loss to reproductive outcomes, a debate has emerged around the implementation of body mass index (BMI) cutoffs that would restrict obese women from infertility treatments. While formal guidelines that directly address this debate do not exist in the United States, many fertility practices both domestically and abroad currently limit access to infertility treatments for obese women. The goal of this chapter is to summarize the current literature addressing the use of BMI as a criterion for access to infertility treatment and ART. The principles of respect for autonomy, justice beneficence/nonmaleficence will be introduced to develop a bioethical framework within which to consider this debate.
Arguments Supporting a BMI Cut Off
In the United States there are currently no official guidelines advocating a specific BMI above which infertility treatment should be discouraged or refused. Globally, however, the recommendation and enforcement of BMI thresholds is prevalent and growing. Examples of these policies and arguments for their use are discussed below.
The New Zealand System
In New Zealand, a clinical ranking system known as clinical priority access criteria (CPAC) was first introduced in the 1990s with a stated goal of ranking patients for elective, publicly funded procedures. In 2000, this was extended to patients seeking treatment for infertility [13]. Given that obesity is considered to decrease the likelihood of successful infertility treatment, the CPAC ranking system was only applied to women within the BMI range of 18–32 [14, 15]. One retrospective study examined the effect of these criteria on women outside of the BMI range, and reported that while similar proportions of women in different BMI categories would have been eligible for publicly funded ART, the number actually receiving treatment was lower in the higher BMI group [14]. They also found that women with a BMI >32 were less likely to receive private ART [14]. The authors argued that women with BMIs between 32 and 35 were able to modify their lifestyle and achieve a weight loss that then enabled them to receive treatment. Those in support of CPAC claim that this system has allowed for more equitable care and greater access to ART in New Zealand and that most evidence supports the need for weight improvement measurements [14]. Evidence cited includes increased rates of infertility, increased maternal and neonatal complications, and increased costs of treatment in overweight and obese women. Also noted, are the benefits of weight loss in improving fertility outcomes in this population [16].
The United Kingdom
While the United Kingdom does not have an enforced BMI threshold for ART, their reproductive societies have recommended BMI ranges for those undergoing ART. The most recent National Institute for Health and Care Excellence (NICE) guidelines suggest that BMI should be in the range of 19–30 kg/m2 before commencing with assisted reproduction, and that a woman with a BMI outside this range is likely to have a lower chance of successful assisted reproduction [17]. The British Fertility Society (BFS) states that infertility treatment should be deferred if BMI is in excess of 35 and that obese infertile women under the age of 37 should be encouraged to reduce their BMI to less than 30 [18]. The basis for these recommendations include diminished odds of natural conception and successful fertility treatment in obese women, as well as the increased risk of miscarriage, pregnancy complications, and congenital anomalies. The BFS also addresses the decreased safety of fertility treatment in obese women and the potential negative long-term health effects on both mother and child [18]. In accord with these recommendations, it has been reported that two-thirds of clinics in the United Kingdom apply a BMI cutoff to patients being evaluated for infertility treatments [19].
Additional Arguments for BMI Cutoffs
Other reports have proposed that women with a BMI >35 should lose weight prior to conception and not prior to receiving infertility treatment [20]. In this case it is argued that given the significant risks of obesity to both the mother and fetus, the woman should actually be protected against pregnancy during the time of weight loss and that the combination of weight loss, contraception, and folic acid should become the standard in the preconceptual care of obese women [20].
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