Risk of stillbirth following in vitro methods
This systematic review and meta-analysis assessed the risk of stillbirth following in vitro methods of conception (IVF, ICSI, with fresh or frozen embryo transfer) in comparison to non-in vitro methods of conception (which could include spontaneous conceptions, IUI, ovarian stimulation). Multiple subgroup analyses were completed to further define and explore this risk. Definitions of stillbirth after 20 weeks' gestational age were included. The main finding was an increased risk of stillbirth following in vitro methods compared to non-in vitro methods. This risk persisted when assessing in vitro methods vs. spontaneous conceptions only. The risk did NOT persist when assessing in vitro methods vs. patient with a history of infertility, but conceiving without in vitro methods (i.e. conceiving spontaneously with a history of infertility, IUI, ovarian stimulation). This data set includes descriptions of included studies, as well as data extracted from studies. The main estimate of effect was the odds ratio, which was chosen because adjusted odds ratio (from multiple logistic regression) account for important confounders such as maternal age, parity, and other obstetrical or medical conditions that increase the risk of stillbirth. Where adjusted odds ratio were not provided by studies, the numbers of total birth, live births, and stillbirths were extracted to calculate odds ratios. Studies were selected for inclusion in meta-analysis to avoid duplication of data i.e. in studies that overlapped in time and place (i.e. country), the study with the largest number of pregnancies was included in the analysis only.