Comparison of implantation and early development of human embryos fertilized in vitro versus in vivo using transvaginal ultrasound.

Abstract

Several reports in the literature suggest delayed implantation of in vitro-fertilized human embryos compared to in vivo-fertilized eggs. The use of high-frequency transvaginal transducers for early detection of pregnancy has allowed the identification of the gestational sac with very low serum human chorionic gonadotropin (beta-hCG) levels. Thus, the present study evaluated whether retarded implantation can be identified using this novel technology. We studied 13 single pregnancies after in vitro fertilization (IVF) and 14 pregnancies after artificial insemination either by husband (n = 6) or donor (n = 8). In the IVF patients, oocytes were retrieved 35 hours after hCG administration. Embryo transfer occurred approximately 48 hours after retrieval. Artificial insemination was performed 24 and 48 hours after hCG administration. Transvaginal ultrasound scans and serum beta-hCG levels were evaluated every 3 days starting day 12 post-hCG administration. Serum beta-hCG levels rose in parallel when in vitro- and in vivo-fertilized embryos were compared. Similarly, there was no difference between groups in the mean time needed to detect early embryonic structures, such as the embryonic sac, yolk sac, and heartbeats, or the growth rate of the gestational sac. In conclusion, there was no difference in detecting implantation and early embryonic development of human embryos fertilized in vivo versus in vitro as ascertained by ultrasound scans and serum beta-hCG levels. An embryonic sac is detected 23-24 days after hCG administration in pregnancies achieved by assisted reproductive techniques.

Earliest ultrasound finding of implantation?

“…2 To whom correspondence should be addressed. similar to an earlier report (5). With this experience, we programmed our U.S. study 18 days after embryo transfer in all IVF/ICSI preembryo recipient women.…”

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“…Implantation is dependent on embryonic age and independent of endometrial maturation during the implantation window (34). There were no significant differences in implantation as judged by early transvaginal ultrasonographic studies between IVF and IUI (35). In vitro, the human embryo culture system is restricted by survival days (up to 14 days after fertilization in recent studies) (27).…”

In vitro fertilisation and gamete intrafallopian transfer: an integrative analysis of research, 1987–1992

“…A possible explanation for the comparability of GnRHa and ∼CC∼ GnRHa protocols once retrieval and transfer had been reached is that, despite the fact that GnRHa produces more mature oocytes per cycle, the fertilisation rate does not appear to improve as a result of the larger harvest (Ron‐El et al 1990; Toner et al 1991). Pellicer et al (1991) have suggested that GnRH agonists may act directly on the ovary to recruit follicles that were undergoing atresia. Such follicles are hypothesised to contain fewer fertile oocytes.…”