Clinical outcomes and placental pathological characteristics
We retrieved data on the following aspects:
1.Basic characteristics: maternal age, fertilization method, height, prepregnancy body mass index (BMI), and mode of delivery.
2.Pregnancy outcomes and complications: gestational age, preterm birth, preeclampsia, gestational hypertension, gestational diabetes mellitus (GDM), postpartum haemorrhage, placenta increta, placenta previa, placental accreta, premature rupture of membranes, placental abruption , placenta weight, position of cord attachment (velamentous placenta, battledore placenta, circumvallate placenta, etc.), and placenta morphology (placenta multipartita, pseudoleaf placenta).
3. Placental pathology: All placentas that met the inclusion criteria and submitted for pathological examination were analysed. The observation indicators included placental calcification, chorioamnionitis, chorionic infarction, haemorrhage, syncytiotrophoblastic nodules hyperplasia, and cellulose deposition.
4. Neonatal outcomes: neonatal malformations, macrosomia (birth weight greater than 4000 g), large for gestational age (a birth weight more than the 90th percentile for gestational age), small for gestational age (a birth weight less than the 10thpercentile for gestational age), neonatal asphyxia, neonatal intensive care unit (NICU) referral rate.