By Will Boggs, MD
Initial success in the first cycle of in vitro fertilisation (IVF) predicts a good chance of subsequent pregnancy and successful delivery in women who are younger than 40 years old, even if the first-cycle pregnancy is lost.
However, the same is not true for women over the age of 40.
"Cumulative live birth rates for women 40 years or older with and without prior pregnancy losses are the same," Dr. Rita Sneeringer told Reuters Health.
Sneeringer from Beth Israel Deaconess Medical Centre, Boston, and associates, explain that pregnancy in the first IVF cycle - even when the pregnancy is lost - is associated with an improved odds of pregnancy in future cycles for women younger than 40 years old.
To investigate the situation in older women, the researchers analysed data on 584 women who underwent an initial IVF cycle when they were older than 40 years. Fifty-seven of these women delivered and were excluded from the analysis, while 49 had a pregnancy loss, and 478 did not become pregnant at all.
There was no significant difference between the women in the prior pregnancy loss group and the women who did not become pregnant. Most women in both groups had unsuccessful results for all subsequent cycles, according to according to the report, which is published in the journal Fertility and Sterility.
Sneeringer concluded: "For younger women, a prior pregnancy loss selects for women most likely to have a successful ongoing pregnancy in a future cycle. However, this is not true for older women over 40 years."
She pointed out that her IVF centre has published a descriptive report on pregnancy rates for women over age 40. "In this analysis of over 2 700 cycles, higher live birth rates were associated with greater number of embryos available for transfer; embryos available for cryopreservation; and twin gestation on initial ultrasound," Sneeringer explained.
The report also shows that fertility rapidly declines in women in their 40s, but IVF can be successful if it is performed before the age of 44.