Satoko Yamashita1, Yuko Ikemoto2, Asako Ochiai2, Satoshi Yamada3, Keiichi Kato4, Motoharu Ohno5, Tomoya Segawa6, Yoshiharu Nakaoka7, Mayumi Toya8, Satoshi Kawachiya9, Yoshiaki Sato10, Toshifumi Takahashi11, Shigeto Takeuchi12, Mari Nomiyama13, Chisa Tabata14, Toshihiro Fujiwara15, Sumihide Okamoto16, Toshihiro Kawamura17, Jun Kawagoe18, Mitsutoshi Yamada19, Yuichi Sato20, Genzo Marumo21, Rikikazu Sugiyama22, Keiji Kuroda23. 1. Juntendo University Faculty of Medicine, Department of Obstetrics and Gynecology, Tokyo 113-8421, Japan; Oita University, Faculty of Medicine, Department of Obstetrics and Gynecology, Oita 879-5593, Japan. 2. Juntendo University Faculty of Medicine, Department of Obstetrics and Gynecology, Tokyo 113-8421, Japan. 3. Hanabusa women's Clinic, Hyogo 650-0021, Japan. 4. Kato Ladies Clinic, Tokyo 160-0023, Japan. 5. Juntendo University Faculty of Medicine, Department of Obstetrics and Gynecology, Tokyo 113-8421, Japan; Saint Mother Obstetrics and Gynecology Clinic, Institute for ART, Fukuoka 807-0825, Japan. 6. Shinbashi Yume Clinic, Tokyo 105-0004, Japan. 7. IVF Namba Clinic, Osaka 550-0015, Japan. 8. Kyono ART Clinic, Miyagi 980-0014, Japan. 9. Kobe Motomachi Yume Clinic, Hyogo 650-0037, Japan. 10. Sophia Ladies Clinic, Kanagawa 252-0233, Japan. 11. Fukushima Medical University, Fukushima Medical Center for Children and Women, Fukushima 960-1295, Japan. 12. ART Reproductive Medical Center, Saiseikai Matsusaka General Hospital, Mie 515-8557, Japan. 13. Takagi Hospital, Department of Obstetrics and Gynecology, Fukuoka 831-0016, Japan. 14. Sanno Hospital, Center for Human Reproduction and Gynecologic Endoscopy, Tokyo 107-0052, Japan. 15. Sanno Hospital, Center for Human Reproduction and Gynecologic Endoscopy, Tokyo 107-0052, Japan; Phoenix ART Clinic, Tokyo 151-0051, Japan. 16. ART Okamoto Women's Clinic, Nagasaki 850-0861, Japan. 17. Denentoshi Ladies Clinic, Kanagawa 227-0062, Japan. 18. Yamagata University Faculty of Medicine, Department of Obstetrics and Gynecology, Yamagata 990-9585, Japan. 19. Keio University School of Medicine, Department of Obstetrics and Gynecology, Tokyo 160-8582, Japan. 20. Tatedebari Sato Hospital, Obstetrics & Gynecology, Gunma 370-0836, Japan. 21. Marumo Ladies Clinic, Department of Obstetrics and Gynecology, Tokyo 106-6004, Japan. 22. Sugiyama Clinic Shinjuku, Center for Reproductive Medicine and Implantation Research, Tokyo 116-0023, Japan. 23. Juntendo University Faculty of Medicine, Department of Obstetrics and Gynecology, Tokyo 113-8421, Japan; Sugiyama Clinic Shinjuku, Center for Reproductive Medicine and Implantation Research, Tokyo 116-0023, Japan. Electronic address: kuroda@sugiyama.or.jp.
Abstract
RESEARCH QUESTION: What is the prevalence of triplet and quadruplet pregnancies after single embryo transfer (SET) in Japan. DESIGN: A retrospective observational study was conducted on 274,605 pregnancies after 937,848 SET cycles in registered assisted reproductive technology (ART) data from the Japanese ART national registry database between 2007 and 2014. A questionnaire survey of ART centres was also conducted. Data on pregnancies with embryo division into three or more after SET were analysed. RESULTS: According to the Japanese ART national registry database, SET resulted in 109 triplet pregnancies (0.04% of pregnancies), and the questionnaire reports from 31 centres revealed 33 triplet and one quadruplet pregnancies. After exclusion of 20 duplicated cases, 122 triplet and one quadruplet pregnancies included 46 monochorionic (one gestational sac [37.4%]), 18 dichorionic (two gestational sacs [14.6%]) and 59 trichorionic pregnancies (three gestational sacs [48.0%]). Compared with singleton pregnancies, patients with monozygotic triplet or quadruplet pregnancies were less frequently diagnosed with unexplained infertility (P = 0.004), more often received gonadotrophin injections for ovarian stimulation in 39 cases with information available (P = 0.021) and underwent more blastocyst transfers and assisted hatching (P = 0.002 and P < 0.001, respectively). The proportion of live birth, defined as at least one baby born, excluding induced abortion, was 64.6% (73/116 pregnancies) of monozygotic triplet or quadruplet pregnancies. CONCLUSIONS: Combined Japanese ART national registry and survey data revealed 122 triplet and one quadruplet pregnancies, the majority after cryopreserved embryo transfer. Most were conceived after blastocyst transfer and often after assisted hatching, which are potential risk factors for zygotic splitting.
RESEARCH QUESTION: What is the prevalence of triplet and quadruplet pregnancies after single embryo transfer (SET) in Japan. DESIGN: A retrospective observational study was conducted on 274,605 pregnancies after 937,848 SET cycles in registered assisted reproductive technology (ART) data from the Japanese ART national registry database between 2007 and 2014. A questionnaire survey of ART centres was also conducted. Data on pregnancies with embryo division into three or more after SET were analysed. RESULTS: According to the Japanese ART national registry database, SET resulted in 109 triplet pregnancies (0.04% of pregnancies), and the questionnaire reports from 31 centres revealed 33 triplet and one quadruplet pregnancies. After exclusion of 20 duplicated cases, 122 triplet and one quadruplet pregnancies included 46 monochorionic (one gestational sac [37.4%]), 18 dichorionic (two gestational sacs [14.6%]) and 59 trichorionic pregnancies (three gestational sacs [48.0%]). Compared with singleton pregnancies, patients with monozygotic triplet or quadruplet pregnancies were less frequently diagnosed with unexplained infertility (P = 0.004), more often received gonadotrophin injections for ovarian stimulation in 39 cases with information available (P = 0.021) and underwent more blastocyst transfers and assisted hatching (P = 0.002 and P < 0.001, respectively). The proportion of live birth, defined as at least one baby born, excluding induced abortion, was 64.6% (73/116 pregnancies) of monozygotic triplet or quadruplet pregnancies. CONCLUSIONS: Combined Japanese ART national registry and survey data revealed 122 triplet and one quadruplet pregnancies, the majority after cryopreserved embryo transfer. Most were conceived after blastocyst transfer and often after assisted hatching, which are potential risk factors for zygotic splitting.