Trying for a Baby—Two Embryos are better than Three, IVF
Assisted reproduction is a costly, emotional, and time-consuming cycle for families. Increasing the odds of conception is however a case of less is more, in relation to how many embryos should be transferred into a woman’s womb. A new fertility study published in Lancent , United Kingdom (UK) found that the odds are no better implanting three or more embryos than just two.
Dr. Scott Nelson, head of reproductive and maternal medicine at the University of Glasgow co-authored the published study. Dr. Nelson, along with Debbie Lawlor of the University of Bristol analyzed data involving 124,000 in vitro fertilization (IVF) cycles in the UK within a 5 year span. What they discovered was in keeping with their established fertility policies.
In the study, women under 40 years old who transferred 2 embryos had a 33 percent success rate overall. When 3 embryos were included, the success rate, represented by the total live birth-rate, dropped to a significant 25 percent.
Women over 40, experienced a more dismal outcome at 13 percent, whether they had 2 or 3 embryos transferred.
The implications of the study are far-reaching and speak volumes to a number of issues related to fertility practices and policies in the United States (U.S.). Currently, the “jury is out” on the debate regarding how many embryos should be transferred, a common question asked by families, with the magic number of four transfers implicitly applied in fertility procedures.
Another element coming out of the study is the belief that more is better. A woman’s hope is raised with the expectation that the odds are in her favor with each additional embryo. As such, the psychological stress and emotional conflicts are rife with these procedures, more so when IVF is unsuccessful.
The last point associated with the findings is the increased risks associated with multiples in pregnancy, an unknown factor, which plague all assisted reproductive procedures. Case in point, the much publicized mother, Nadya Sulemon, labeled the “octomom.” She had 12 embryos implanted, which resulted in octuplets.
The American Society for Reproductive Medicine has policies governing fertility practices, but enforcement rules are lax.
In the UK transferring 3 embryos in women, under 40, is banned. In Western Europe many authorities recommend a single embryo transfer for women under 37 and a maximum of 2 embryos for women 37 to 40. “For women over 40, three is often the limit by law.”