In fertility treatments such as in vitro fertilization (IVF), embryos created in a Petri dish are implanted into a woman’s uterus after 3-5 days of incubation. Until recently, it was assumed that such embryos have a normal development if they successfully implant. A disturbing recent report reveals a higher risk after IVF: 8% of babies with various birth defects, compared with 6% of babies conceived naturally. The defects include cardiac, renal, and muscle problems, as well as cerebral palsy.
Once corrections are made for the health and socioeconomic status of the mothers, the increased risk disappears, except for babies conceived by a special technique called intracytoplasmic sperm injection (ICSI), an increasingly popular method used in fertility clinics around the world.
The study appeared in the New England Journal of Medicine for May 10, 2012, and involved more than 300,000 births in South Australia, including slightly more than 6000 births using assisted reproductive technologies.