Intrauterine fertilization capsules--a clinical trial

First pregnancies and livebirths from transfer of sodium alginate encapsulated embryos in a rodent model

OBJECTIVE

To determine the effect of sodium alginate encapsulation of rodent embryos on in vitro embryonic cleavage rates, implantation rates, and livebirth rates, and to find the in vivo degradation time for the capsules.

DESIGN

Studies were conducted using both CB6F1 mice and Golden Syrian hamsters.

RESULTS

Capsules made with 3.0% sodium alginate degraded in vivo within 24 to 48 hours after transfer. In vitro embryonic cleavage of encapsulated embryos was not impaired, nor were implantation rates in CB6F1 mice. Finally, 8.6% of transferred encapsulated embryos resulted in livebirths.

CONCLUSIONS

Encapsulation of rodent embryos in 3.0% sodium alginate is not detrimental to embryonic development, implantation rates, or fetal development. Because the capsule degrades within 48 hours after transfer, encapsulating embryos may be beneficial for human in vitro fertilization and embryo transfer.

Gamete intrauterine transfer

Gamete intrauterine transfer has been performed at a very limited scale until now. The main target group of patients for such a treatment would be women with infertility due to the tubal factor, but other infertile patients could benefit also, as the procedures reduce incubation time in the laboratory and implies fertilization in vivo. Few studies have been reported from 1982 to 1990 on the transfer of oocytes and spermatozoa directly to the uterus, and only five clinical pregnancies have been achieved. Transfer of oocytes and spermatozoa inside a biodegradable capsule has only been performed in one study comprising 26 cycles with no ensuing pregnancies. A critical evaluation and a status is carried out.