IVF or In-Vitro Fertilization is a fertility treatment where the woman is given ovulation inducing hormones to produce multiple eggs. These eggs are retrieved and fertilized with the partner’s sperm. Once they begin to grow, these embryos are transferred back to the woman’s uterus. However, as IVF is expensive, physically and emotionally taxing, and success rate is not very high with only one embryo transfer, multiple embryos are placed back to give the parents a higher chance of success.
Although placing more than one embryo back into the uterus increases the likelihood of a pregnancy, it also increases the chances of twin and triplet births. As opposed to a normal fertilization, where only one egg is released during ovulation and if fertilized leads to a singleton birth, couples opting for IVF are more likely to have twin or multiple births.
During the initial years when IVF gained popularity, the twin and triplet birth ratios were very high. However, as multiple gestations are more likely to result in premature deliveries and other pregnancy complications, doctors are trying to cut back on placing a large number of embryos back to minimize these risks. Regardless of these practices, even today, twin births after fertility treatments are much more common than normal conception.
These modern day medical advances provide a number of infertile couples the chance of having children. Many parents choose to get a larger number of embryos transferred back in hopes of having twins the first time around, as they cannot afford to go through IVF treatment repeatedly!