Obstetric outcomes and congenital abnormalities in infants conceived with oocytes matured in vitro

Today a key component to infertility treatment with in vitro fertilization (IVF) is controlled ovarian hyper-stimulation (COH), a process whereby supra-physiological amounts of exogenous gonadotropins are administered for the purpose of inducing multi-follicular growth. It is generally accepted that the number of mature oocytes retrieved relates to the number of embryos available for transfer which in turn correlates with the likelihood of treatment success. However, side effects of COH (short and possibly long-term) continue to raise concerns (van Leeuwen et al., 2011). Robert Edwards, the pioneer of IVF believed that recovery of immature oocytes followed by in vitro maturation (IVM) would be one of the potentially useful treatments for women with infertility (Edwards, 2007a,b). IVM of immature eggs has emerged as a gonadotropin-independent treatment alternative to conventional IVF (Chian et al., 2004; 2013). IVM differs from conventional IVF treatment in two major ways. First is the absence of COH and second is the collection of immature oocytes that are cultured in vitro until they reach the metaphase II (mature) stage before IVF is performed. Since the introduction of IVF and other assisted reproductive technologies (ARTs) for infertility treatment, the health of infants born from these techniques has been a major concern. Individual studies have examined the birth weight and major defects in infants born from IVF or other ART procedures, but with conflicting results (Hansen, 2002; Schieve LA et al., 2002; Rimm et al., 2004; Davies et al., 2012). Obstetric outcomes and congenital abnormalities in infants conceived with oocytes matured in vitro