Author Interviews, Fertility, OBGYNE / 19.03.2019 Interview with: Prof. Daniel R Brison PhD, FRCPath Scientific Director Department of Reproductive Medicine Manchester University NHS Foundation Trust Old St. Mary's Hospital Manchester U.K and Catherine M Castillo PhD Maternal & Fetal Health Research Centre Division of Developmental Biology and Medicine School of Medical Sciences, Faculty of Biology, Medicine and Health The University of Manchester What is the background for this study? What are the main findings? Response: IVF conceived children have been known to have poorer birth outcomes when compared to spontaneously conceived children. Even when excluding twins and triplets, which result from more complicated pregnancies, IVF singletons have an increased risk of low birth weight and being born small for “dates” (length of gestation). This is important as studies carried out in non-IVF children show that low birth weight is associated with slightly higher risk of disease in later life. We knew from the literature that birth outcomes differed within the IVF population depending on the type of treatment used; for example, singletons conceived from frozen/thawed embryos are born with higher average birth weights when compared to their fresh embryo conceived counterparts. Our research team wanted to investigate whether IVF practices and technologies per se (which have advanced quite rapidly over the years since 1978 when the first IVF baby was conceived) were associated with differences in singleton birth weight. In attempting to quantify historical changes in laboratory practice going back as far as we could, we discovered that our outcome of interest – birth weight – had indeed increased notably throughout the time period covered by the available data. Besides observing an increase in birth weight of almost 180g over the study period (when accounting for child gender, gestational age and maternal parity), we also observed that frozen embryo transfer was associated with higher birth weight, and spontaneous fetal reduction and longer duration of infertility were associated with lower average birth weight. (more…)
Author Interviews, NEJM, OBGYNE / 06.12.2013 Interview with: Aniket D. Kulkarni, M.B., B.S., M.P.H Women's Health and Fertility Branch Centers for Disease Control and Prevention Atlanta, Georgia What are the main findings of the study? Dr. Kulkarni: Our study estimates the contribution of fertility treatments and natural conception to multiple births. Fertility treatments include IVF and non-IVF treatments. Non-IVF treatments primarily include ovulation induction and ovarian stimulation coupled with timed intercourse or intrauterine insemination (IUI). All estimated proportions were adjusted for maternal age which makes this study unique. The incidence of twin births nearly doubled and the incidence of triplet and higher-order births quadrupled over the last 4 decades. Our study estimates that by 2011, a total of 36% of twin births and 77% of triplet and higher-order births resulted from conception assisted by fertility treatments, after adjusting for maternal age. After initial increase, the incidence of triplet and higher order births decreased by 29% from 1998 to 2011. The decrease in triplet and higher order births has coincided with a 70% reduction in the transfer of 3 or more embryos during IVF and a 33% decrease in the proportion of triplet and higher order births attributable to IVF. The decline in the number of embryos transferred during IVF became possible due to monitoring of ART treatments and outcomes and the work of professional societies, which have repeatedly revised practice guidelines to include recommendations for lowering the number of embryos transferred. In contrast, non-IVF fertility treatments of ovulation induction and ovarian stimulation are estimated to contribute the increasing number of multiple births. Hence there is a need for surveillance of births from non-IVF fertility treatments. (more…)