New Infertility Research

According to the medical journal, Fertility and Sterility:

The health of infants born through in vitro fertilization (IVF) is linked to specific techniques used and the parents’ infertility diagnoses. More specifically, researchers have found a link between the uterine environment and outcomes, namely the baby’s birth weight and length of gestation.

We have known that IVF babies tend to have lower birth weights and shorter gestation periods (affecting mortality and infant health rates) compared with naturally conceived infants. Now further studies have revealed that that factors relating to the underlying infertility, more than the means of conception (articifical or natural), adversely affect infant health.

When a doctor used the couple’s own gametes (eggs, sperm), as compared with donor gametes, researchers found no negative effect on birth weight or gestational age. Yet infants born to surrogate mothers had better birth weights and gestational ages. Infertility patients with a “uterine” cause for her infertility tended to have babies with lowest birth weights and gestational ages. What does this suggest? Probably that the uterine environment is more important than the quality of gametes.

But what about different types of IVF? The embryo may be transferred to “drugged-up” uterus vs. one with a natural environment. Typically with IVF, an embryo is transferred immediately to a woman who has received medications for controlled ovarian hyperstimulation. But in the case of IVF with a donor egg or a surrogate mother, the embryo is transferred to an un-stimulated uterus (no meds).

Scientists found that frozen-embryo transfers (no drugs for uterus) did better than standard IVF embryos. While in the past we've thought the egg quality mattered most, now we're considering the uterine quality.

So what’s the next step? To look at how different types of female infertility affect the uterine environment, and how we can use this data to predict IVF success.