P1-18 Studying early pregnancy during infertility treatment may identify novel risk factors for congenital malformations

Introduction The study of early pregnancy risk is generally very difficult, but potentially feasible in women during clinical infertility treatment with gamete and embryo data, known gestation, routine ultrasound in early pregnancy, and detailed recording of birth outcomes. Methods All treatment cycles of assisted reproductive technology (ART) for the period January 1986 to December 2002 in South Australia were linked to both the routine State perinatal collection and the registries for birth defects and cerebral palsy (coded to ICD-9 BPA). Fetal loss was assessed by comparing routine 6 week ultrasound data and babies delivered. ORs for birth defects were calculated for deliveries with an empty fetal sac at 6 weeks, or subsequent fetal loss and a baby delivered, compared to singleton pregnancies without loss. Results The prevalence of congenital malformations was 14.6% in pregnancies in which there had been an empty sac at a 6 week ultrasound. The presence of an empty sac was associated with both an increased risk of any malformation (OR=1.93, CI 1.10 to 3.39) and with multiple malformations (OR=2.78, CI 1.27 to 6.03). Multiple pregnancy without fetal loss was not associated with an overall increased prevalence of malformation (OR=1.01, CI 0.81 to 1.25). Conclusions The presence of an empty fetal sac at 6 weeks gestation constitutes a significant risk factors for congenital malformations in the surviving baby. Subsequent work identifying upstream factors influencing embryo development and loss have significant potential for advancing our understanding of the aetiology of congenital malformations, particularly after infertility treatment

Congenital malformations · Fetus · Gestation · Gynecology · Infertility · Live birth · Obstetrics · Pregnancy · Assisted Reproductive Technology and Twin Pregnancy · Ectopic Pregnancy Diagnosis and Management · Medicine · Prenatal Screening and Diagnostics