Selected single blastocyst transfers maintained pregnancy outcome and eliminated multiple pregnancies.

Abstract

Background: Transfer of more than one embryo following in vitro fertilization/intracytoplasmic sperm injection cycles have increased pregnancy rate at the cost of increasing the incidence of triplets and twins. It has been proposed that prolonged culture to the blastocyst stage would automatically result in the selection of good quality embryos for transfer and minimize the incidence of triplets and twins. Methods and Results: The objectives of the present retrospective analysis were to examine the pregnancy outcome, multiple pregnancy and related data following: (i) single blastocyst transfer (BT) and double BT; (ii) single BT in patients belonging to different age groups; and (iii) good, fair or poor quality of BT. A total of 260 BT were carried out between August 1998 and July 2002 and they are included in the current study. Sixty of the 260 BT patients received a single BT, and 41 of them received selected single good quality BT (SSBT). The implantation rate has no significant difference between following single BT (53.3%) and double BT (42.8%). No multiple pregnancy occurred following single BT, while significantly higher (P<0.05) multiple pregnancy rate was observed following a double BT (45.8%). The clinical pregnancy and implantation rates following a single BT were similar (P>0.05) in patients belonging to <30years (62.5%), 30-34years (57.9%) and 35-39years old (35.8%). Conclusion: Selected single good quality BT maintained pregnancy and avoided multiple pregnancies. It is recommended for patients with a risk for high-order multiple pregnancy. (Reprod Med Biol 2004; 3: 13-18).