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J Assist Reprod Genet (2011) 28:517524 DOI 10.1007/s10815-011-9592-y
REVIEW
The impact of obesity on egg quality
Scott H. Purcell & Kelle H. Moley
Received: 26 April 2011 /Accepted: 23 May 2011 /Published online: 28 May 2011 # Springer Science+Business Media, LLC 2011
Abstract Obesity in women is a concern in many countries. This causes numerous health issues; however, this review focuses on the impact of obesity on womens reproduction, and in particular the oocyte. Data from infertility clinics and experimental animal models that address the effects of obesity are presented. Bidirectional communication and metabolic support from the surrounding cumulus cells are critical for oocyte development, and the impact of obesity on these cells is also addressed. Both oocyte maturation and metabolism are impaired due to obesity, negatively impacting further development. In addition to reproductive hormones, obesity induced elevations in insulin, glucose, or free fatty acids, and changes in adipokines appear to impact the developmental competence of the oocyte. The data indicate that any one of these hormones or metabolites can impair oocyte developmental competence in vivo, and the combination of all of these factors and their interactions are the subject of ongoing investigations.
Keywords Oocyte . Cumulus cell . Obesity. Metabolism . Infertility
Introduction
Maternal obesity is a growing problem in many parts of the world. It is generally defined using the body mass index (BMI) measurement in the units kg/m2. Based on World Health Organization (WHO) standards, a BMI of 18.524.9 is considered normal, 2529.9 overweight, and 30 as obese. In the US it is estimated that almost a quarter of reproductive-age women have a body mass index (BMI) 30 [1] and obesity is estimated to affect more than one-third of all US adults [2]. This has consequences for reproductive health. Obese women are almost three times more likely than non-obese women to have some degree of infertility and may take longer to conceive, even if cycling regularly [3, 4]. Studies have shown that obese women who do become pregnant have an increased risk of miscarriage, preeclampsia, gestational diabetes, and congenital defects in offspring [5]. In addition to obesity alone, polycystic ovarian syndrome (PCOS) is a common metabolic disorder in reproductive-aged women commonly associated with luteinizing hormone (LH) hypersecretion, hyperandrogenism, insulin resistance, and anovulation...