Health of IVM children

Abstract

In vitro maturation (IVM) is an emerging type of assisted reproductive technology (ART), in which immature as opposed to mature oocytes are collected from the ovaries and allowed to mature in vitro prior to fertilisation by either standard in vitro fertilisation (IVF) on intracytoplasmic sperm injection (ICSI). Since the first report of a human birth resulting from IVM in 1991 [1], it is estimated that over 1,300 babies have been born following the technique [2] (in contrast to an estimated 3 million babies conceived by standard IVF and ICSI over the last 30 years). IVM offers a number of potential benefits when compared to standard IVF, principally related to the avoidance of high doses of hormonal stimulation with gonadotrophins and GnRH analogues. In patients with polycystic ovary syndrome (PCOS) this avoids the risk of ovarian hyperstimulation syndrome (OHSS). The high costs of hormonal therapy also make IVM cheaper than conventional alternatives. Immature oocyte retrieval, without the need to wait for hormonal stimulation and in vivo maturation, offers the possibility of expedient oocyte cryopreservation for patients diagnosed with cancers without delaying cancer treatment. However, despite recent improvements, pregnancy rates with IVM remain lower than with conventional IVF, and higher miscarriage rates have been reported with IVM [2]. For these reasons IVM has yet to become widely used in the field of ART. Given that IVM is not yet a mainstream ART technique, it is not surprising that there is very limited follow-up data regarding the health of children conceived following its use. This is in contrast to a significant volume of high quality studies that have followed-up children conceived following standard IVF and ICSI. In this article we discuss hypothetical concerns regarding the health of IVM children, and review the few studies published in this area. Health of IVF & ICSI children High multiple pregnancy rates continue to be the single greatest factor adversely impacting upon the outcome of ART pregnancies [3, 4], with resulting increased risk of preterm delivery, low birth weight, and perinatal mortality. However, evidence regarding the health of ART singletons when compared to spontaneously conceived singletons is generally reassuring. The majority of studies investigating the risk of congenital malformations, neurodevelopmental outcome, physical health, growth, and psychosocial well-being in ART children are reassuring [5, 6]. Concerns have been raised that ART children may exhibit higher rates of cancer [7] and rare imprinting disorders [8] (such as Beckwith-Wiedemann Syndrome and Angelman Syndrome), however larger studies are required to confirm these associations. Risks of infertility and cardiovascular disease in later life remain unexplored areas of concern and require follow-up of cohorts of ART children to continue into adulthood.