Birth rates similar for ART, natural conception

• Analysis of SART data shows hope for ART outcomes

• Use of donor eggs reduced negative impact of advancing age on ART

Not only do live-birth rates with assisted reproductive technology (ART) approach those with spontaneous conception, but success rates do not diminish with advancing maternal age if donor oocytes are used.  So says an analysis of data on more than 250,000 women.

Researchers from around the United States set out to determine cumulative live-birth rates across multiple cycles of ART, rather than per cycle pregnancy rates, in an effort to provide women and their physicians with more meaningful information about which methods provide the greatest success for each woman individually.

To do so, they used the Society for Assisted Reproductive Technology’s database to look at outcomes for women undergoing treatment between 2004 and 2009. With information on almost 500,000 cycles of ART and more than 140,000 live births, the authors linked cycles to individual women, thereby estimating cumulative live-birth rates per cycle.

Published in The New England Journal of Medicine, the findings show that live births occurred in about one-third (30%) of cycles and in just over half (57%) of the women. Rates were highest in women younger than age 31 and fell with advancing age. In women younger than age 31, after 3 cycles “conservative” and “optimal” live-birth rates  were 63.3% and 74.6%, respectively. (In women who did not return for subsequent treatment, conservative rates assumed no live births, whereas optimal rates assumed the opposite.)  These rates fell to 18.6% and 27.8%, respectively, in women aged 41 or 42, and to 6.6% and 11.3%, respectively, in women aged 43 and older. In women who used donor oocytes, conservative and optimal rates remained at >60% and >80%, respectively, regardless of maternal age.

In comparison, the researchers point out, the estimated natural fertility rate for the population at large is about 20% monthly. Approximately 45%, 65%, and 85% of women will conceive after 3, 6, and 12 months, respectively, of unprotected intercourse.

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