TWIN PREGNANCY AFTER THE TRANSFER OF TWO EMBRYOS
Abstract
Background. Twin pregnancy rates following the transfer of two embryos in in vitro fertilization (IVF) treatment are high. Therefore, the aim of this study was to evaluate twin pregnancy rates in regard to the developmental stage of the embryo, patient age, and cause of infertility.
Methods. A retrospective analysis involved 1222 IVF procedures. Overall pregnancy rates and twin pregnancy rates following the transfer of two blastocysts or two cleavage-stage embryos were assessed. The blastocyst group was divided into four age subgroups, and into four subgroups by the cause of infertility.
Results. After the transfer of two blastocysts or two cleavagestage embryos the overall pregnancy rates (45% vs. 9%) and the twin pregnancy rates (18% vs. 5%) were significantly higher in the blastocyst group. The effects of patient age and the transfer of two blastocysts on the overall pregnancy and twin pregnancy rates were significantly greater in the subgroups of patients aged ≤ 30 years (21%) and 31–34 years (20%) than in older patients (35–38 years = 15.7%; ≥ 39 years = 9%). In the blastocyst group the twin pregnancy rate was significantly higher in patients with tubal (21%) and endocrinological causes of infertility (24.5%) than in patients with endometriosis (7%) and uterine malformations (12.5%).
Conclusions. After the transfer of two blastocysts twin pregnancy rates are significantly higher in patients with tubal factor or endocrinological causes of infertility younger than 34 years. In this population of women the risk of twin pregnancy can be avoided by the transfer of a single embryo – most developed blastocyst.
Downloads
References
Meden-Vrtovec H, Virant-Klun I, Tomaževič T et al. Program zunajtelesne oploditve na Ginekološki kliniki v Ljubljani. Zdrav Vestn 2001; 70: 89–95.
Gardner DK, Vella P, Lane M, Wagle YL, Schlenker T, Schoolcraft WB. Culture and transfer of human blastocysts increases implantation rates and reduces the need for multiple embryo transfers. Fertil Steril 1998: 69: 84–8.
Jones GM, Trounson AO, Gardner DK, Kausche A, Lolatgis N, Wood C. Evolution of a culture protocol for succesful blastocyst development and pregnancy. Hum Reprod 1998; 13: 169–77.
Jones GM, Trounson AO, Lolatgis N, Wood C. Factors affecting the success of human blastocyst development and pregnancy following in vitro fertilization and enbryo transfer. Fertil Steril 1998; 70: 1022–9.
Virant-Klun I, Veble A, Valentinčič B et al. Zamrzovanje in odmrzovanje zarodkov v programu zunajtelesne oploditve. Zdrav Vestn 1998; 67: 495– 9.
Virant-Klun I, Tomaževič T, Bačer Kermavner L, Valentinčič-Gruden B, Mivšek J, Meden-Vrtovec H. Successful freezing and thawing of blastocysts cultured in sequential media. Fertil Steril 2003; 6, v tisku.
Gardner DK, Lane M, Stevens J, Schlenker T, Schoolcraft WB. Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer. Fertil Steril 2000; 73: 1155–8.
Vilska S, Tiltinen A, Hyden-Grankog C and Hovatta O. Elective transfer of one embryo results in an acceptable pregnancy rate and eliminates the risk of multiple birth. Hum Reprod 1999; 14: 2392–5.
The Author transfers to the Publisher (Zdravniški vestnik/Slovenian Medical Journal) all economic copyrights following form Article 22 of the Slovene Copyright and Related Rights Act (ZASP), including the right of reproduction, the right of distribution, the rental right, the right of public performance, the right of public transmission, the right of public communication by means of phonograms and videograms, the right of public presentation, the right of broadcasting, the right of rebroadcasting, the right of secondary broadcasting, the right of communication to the public, the right of transformation, the right of audiovisual adaptation and all other rights of the author according to ZASP.
The aforementioned rights are transferred non-exclusively, for an unlimited number of editions, for the term of the statutory
The Author can make use of his work himself or transfer subjective rights to others only after 3 months from date of first publishing in the journal Zdravniški vestnik/Slovenian Medical Journal.
The Publisher (Zdravniški vestnik/Slovenian Medical Journal) has the right to transfer the rights, acquired parties without explicit consent of the Author.
The Author consents that the Article be published under the Creative Commons BY-NC 4.0 (attribution-non-commercial) or comparable licence.
