Corresponding author
Hui Wang, M.D.
Assisted Reproduction Center, Northwest Women’s and Children’s Hospital,
Xi’an, People’s Republic of China.
Mail: 73#, Houzaimen North Street, Xi’an, China
E-mail: wanghuiart@126.com
a Assisted Reproduction Center, Northwest Women’s and
Children’s Hospital, Xi’an, People’s Republic of China.
b Medicine Department, Nursing and Health Sciences,
Monash University, Melbourne, Victoria, Australia.
c University of Melbourne Department of Obstetrics and
Gynaecology, Royal Women’s Hospital, Parkville, Victoria, Australia
d Pregnancy Research Centre, Department of
Maternal-Fetal Medicine, Royal Women’s Hospital, Parkville, Victoria,
Australia
e Leuven Institute for Fertility & Embryology,
Schipvaartstraat 4, 3000 Leuven, Belgium.
Objective: To evaluate if elective single-blastocyst transfer
(eSBT) could be adopted in women aged 36 or older?
Design: Retrospective cohort study.
Setting: Reproductive medicine center at a tertiary hospital.
Population: Women aged ≥36 years received IVF ovarian
stimulation cycles and had ≥ two blastocysts. Out of 429 women, 240
underwent eSBT and 189 double-blastocyst transfer (DBT) in the first
transfer cycle. The subsequent frozen-thawed embryo transfer cycles were
a combination of single- and double- blastocyst transfers.
Methods: Analysis was stratified for patients in age groups
36-37, 38-39 and ≥40, taking into account the quality of the blastocyst
transferred, as graded by morphological examination.
Main outcomes measures: Cumulative livebirth rate (cLBR) from
all transfers (fresh and frozen) accruing from a single oocyte
retrieval.
Results: The cLBR was 74.2% (178/240) versus 63.0% (119/189)
after eSBT versus DBT, respectively (aOR: 1.09 (0.68, 1.75)). Time to
live birth did not vary significantly between the two groups (HR: 0.85
(0.68,1.08)). The total number of children born was 194 after eSBT (162
singletons and 16 pairs of twins) versus 154 (84 singletons and 35
twins) pairs of after DBT. The odds ratios for preterm birth
(<37 weeks’ gestation) (0.37 (0.21-0.64)), and low birthweight
(<2.5 kg) (0.31 (0.16, 0.60)) were all lower in eSBT group
than in DBT group.
Conclusions: In women aged ≥36 years old with at least two
blastocysts, cLBR following single- versus double- blastocyst transfer
was comparable while the odds of multiple livebirths and adverse
perinatal outcomes were reduced.
Keywords : Infertility: Assisted conception; Multiple pregnancy