Women who use in-vitro fertilization (IVF) to become pregnant appear to be slightly more likely to have a boy, according to a study from Australian researchers. Published September 29, 2010, in the British Journal of Obstetrics and Gynaecology, the study looked at data from 14,000 live births following fertility treatment in clinics in Australia and New Zealand between 2002 and 2006. The likelihood of an IVF birth resulting in a boy appeared to increase depending on how soon the fertilized egg was transferred. More boys seemed to result from embryos that were transferred to the womb four days after fertilization (54.1 percent) compared to two to three days after fertilization (49.9 percent).
This would mean that in every hundred births, up to 56 would be baby boys and 44 would be girls, researchers note. In comparison, there are 51 boys and 49 girls in every hundred births with natural conception.
Undergoing intracytoplasmic sperm injection (ICSI) instead of traditional IVF? You may be more likely to have a girl. According to the same study, in every hundred birth using ICSI, 51 babies were girls and 49 boys.
This news may be intriguing for couples who strongly prefer one gender over the other, but, "patients should certainly not consider using this as a method of trying to have a boy or girl, since the procedure used needs to be selected to try and maximize the chance of pregnancy," cautions Dr Allan Pacey, a fertility expert from the University of Sheffield not involved with the study, in an interview with the BBC.