OBJECTIVETo investigate the relationship between pathological abnormalities of placenta and small-for-gestational-age neonates.

METHODSOne hundred placentas of small-for-gestational-age (SGA group) and 200 appropriate-for-gestational-age (AGA group) with single living birth in third trimester were investigated by gross and microscopic examination. The AGA placentas were collected from 2 cases following every SGA placenta. All cases were collected from Shanghai Changning District Maternity and Infant Health Hospital from January 2010 to December 2011.

RESULTSThe gestational week, neonatal birth weight, full-term neonatal birth weight, the preterm birth rate and vaginal spontaneous delivery rate were significantly lower in SGA group than that in AGA group (P < 0.002). Full-term placental volume, placental weight and fetal placental weight ratio were lower in SGA group than that in AGA group (P < 0.05). Unusual insertion and torsion of umbilical cord were more common in SGA group (P < 0.05). Syncytial knots increase, avascular villi and villous infarcts were significantly higher in SGA group (P < 0.005), but there were no significant difference between SGA group and AGA group in intervillous thrombi, chronic villitis and chorangiosis (P > 0.05). Gestational hypertension disease and abnormality of fetal monitoring were more common in SGA group (P < 0.05).

CONCLUSIONSGestational hypertension disease is the main clinical cause of SGA. Some placental abnormality can affect the growth and development of intrauterine fetus.