OBJECTIVE: To evaluate the effect of embryo stage at transfer on placental histopathology and perinatal outcome in singleton live births resulting from fresh embryo transfers (ETs). DESIGN: Retrospective cohort study. SETTING: Not applicable. PATIENT(S): The study population included all live births after fresh ETs during the period from 2009 to 2017. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Primary outcomes included anatomic, inflammatory, vascular malperfusion, and villous maturation placental features. Secondary outcomes included fetal, maternal, and perinatal complications. RESULT(S): A total of 677 live births were included in the final analysis and were allocated to the cleavage-stage (n = 252) and blastocyst (n = 425) ET groups. After the adjustment for confounding factors, the blastocyst group was found to be associated with a higher incidence of circummarginate membranes insertion (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.2-3.4), delayed villous maturation (OR 8.5, 95% CI 1.2-69.3), chorangiosis (OR 2.0, 95% CI 1.2-3.8), parenchymal calcifications (OR 10.6, 95% CI 1.4-80.2), and intrapartum nonreassuring fetal heart rate tracing (OR 2.4, 95% CI 1.3-4.5). Compared with cleavage-stage ETs, live births resulting from the blastocysts were associated with a lower incidence of velamentous cord insertion (OR 0.5, 95% CI 0.3-0.9), retroplacental hematoma (OR 0.3, 95% CI 0.1-0.8), subchorionic thrombi (OR 0.3, 95% CI 0.1-0.8), and avascular villi (OR 0.2, 95% CI 0.03-0.7). CONCLUSION(S): Live births resulting from fresh cleavage-stage and blastocyst ETs have different placental histopathology features, with a higher rate of intrapartum nonreassuring fetal heart rate tracing in the blastocyst group.
OBJECTIVE: To evaluate the effect of embryo stage at transfer on placental histopathology and perinatal outcome in singleton live births resulting from fresh embryo transfers (ETs). DESIGN: Retrospective cohort study. SETTING: Not applicable. PATIENT(S): The study population included all live births after fresh ETs during the period from 2009 to 2017. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Primary outcomes included anatomic, inflammatory, vascular malperfusion, and villous maturation placental features. Secondary outcomes included fetal, maternal, and perinatal complications. RESULT(S): A total of 677 live births were included in the final analysis and were allocated to the cleavage-stage (n = 252) and blastocyst (n = 425) ET groups. After the adjustment for confounding factors, the blastocyst group was found to be associated with a higher incidence of circummarginate membranes insertion (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.2-3.4), delayed villous maturation (OR 8.5, 95% CI 1.2-69.3), chorangiosis (OR 2.0, 95% CI 1.2-3.8), parenchymal calcifications (OR 10.6, 95% CI 1.4-80.2), and intrapartum nonreassuring fetal heart rate tracing (OR 2.4, 95% CI 1.3-4.5). Compared with cleavage-stage ETs, live births resulting from the blastocysts were associated with a lower incidence of velamentous cord insertion (OR 0.5, 95% CI 0.3-0.9), retroplacental hematoma (OR 0.3, 95% CI 0.1-0.8), subchorionic thrombi (OR 0.3, 95% CI 0.1-0.8), and avascular villi (OR 0.2, 95% CI 0.03-0.7). CONCLUSION(S): Live births resulting from fresh cleavage-stage and blastocyst ETs have different placental histopathology features, with a higher rate of intrapartum nonreassuring fetal heart rate tracing in the blastocyst group.