BACKGROUND: Blastocyst culture became a significant technology now. But it provided not only advantages but also disadvantages. Although prolonged in vitro exposure may cause damage to the embryo, but it would choose better embryo to transfer. Our purpose was to probe neonatal and maternal outcomes after blastocyst transfer versus cleavage stage embryo transfer.
METHODS: This is a retrospective cohort study from a single center (1477 singleton birth).
RESULTS: There was a high risk of preterm birth after blastocyst transfer versus cleavage stage embryo transfer (9.9% vs. 5.7%, p=0.02). But we did not find any difference in low birth weight, small for gestational age, large for gestational age, very preterm birth, very low birth weight, antepartum haemorrhage, placental abruption, placenta previa, post-partum haemorrhage and premature rupture of membranes, birth defects, perinatal mortality, APGAR score <7 at 5 min and gestational diabetes. Binary logistic regression indicated that body mass index is an important factor in small for gestational age (COR 0.86, 95% CI 0.80- 0.92; AOR 0.86, 95% CI 0.80-0.92, P=0.00) and large for gestational age (COR 1.17, 95% CI 1.11-1.22; AOR 1.15, 95% CI 1.10-1.21, P=0.00). And the type of infertility, years of unwanted childlessness and parity also influenced large for gestational age.
CONCLUSION: Neonatal and maternal outcomes after cleavage stage embryo transfer were similar with blastocyst transfer except preterm birth. And body mass index played an important role in large for gestational age. Types of ectopic pregnancies so to preserve the woman’s potential fertility.