足月新生儿胎盘形态学指标与出生体重关联出生队列研究

Relationship between placental morphological parameters and birth weight in term newborns: a birth cohort study

目的探讨足月新生儿中胎盘各形态学指标对出生体重的影响作用。方法于2013年5月-2014年9月,对来自马鞍山优生优育队列(MABC)中妊娠8~14周期间纳入的3474名孕妇,于孕早、中、晚期收集其社会人口学信息和妊娠并发症等,在胎儿分娩后测量并记录新生儿体格发育数据和胎盘形态学指标数据,计算2604名足月、单胎儿的胎盘表面积及体积,采用方差分析或χ^2检验描述各指标的基本分布特征,logistic回归模型分析胎盘形态学指标和出生体重的可能关联以及性别差异。结果在2064名研究对象中,各胎盘形态学指标的均数分别为胎盘长径18.95 cm、宽径16.61 cm、厚径2.35 cm、表面积248.67 cm^2以及体积390.72 cm^3,均随新生儿出生体重的增加而增大。控制混杂因素进行logistic回归分析表明,胎盘长径较小(OR=2.15,95%CI=1.46~3.15)、宽径较小(OR=1.71,95%CI=1.17~2.50)、表面积较小(OR=2.94,95%CI=2.08~4.16)、体积较小(OR=3.84,95%CI=2.01~4.01)均是小于胎龄儿(SGA)危险因素;而胎盘长径较大(OR=0.48,95%CI=0.25~0.95)和表面积较大(OR=0.54,95%CI=0.29~0.99)是SGA的保护因素;胎盘长径较大(OR=2.23,95%CI=1.66~2.99)、宽径较大(OR=1.54,95%CI=1.14~2.09)、厚径较大(OR=2.60,95%CI=1.92~3.54)、表面积较大(OR=3.54,95%CI=2.69~4.65)和体积较大(OR=4.34,95%CI=3.28~5.75)均是大于胎龄儿(LGA)的危险因素;而胎盘宽径较小(OR=0.38,95%CI=0.24~0.61)、表面积较小(OR=0.43,95%CI=0.27~0.70)和体积较小(OR=0.48,95%CI=0.29~0.78)是LGA的保护因素。按新生儿性别分层后得出,胎盘宽径较小对SGA发生风险的影响仅存在于男婴中,胎盘宽径较大对LGA发生风险的影响仅存在于女婴中,胎盘体积较小对LGA发生风险的影响仅存在于男婴中。结论胎盘形态学大小与胎儿宫内生长密切相关,同时受胎儿性别的影响。

Objective To explore the effect of various morphological indexes of placenta on birth weight in full-term neonates.Methods From the Ma′anshan-Anhui Birth Cohort(MABC)–a study on eugenics in Anhui province,we consecutively recruited 3474 women at 8–14 gestation weeks between May 2013 and September 2014.Information on sociodemographics and pregnancy complication at first,second,and third trimester were collected among the pregnant women;physique of the newborns and morphological parameters of placentae were measured at the deliveries of the women.Placental surface area and volume were calculated for 2604 pregnant women with full-term singleton.Analysis of variance and chi-square test were used to describe distribution characteristics of the data collected.Logistic regression model was used to analyze the relationship between placental morphological indicators and birth weight.Results The means of placenta morphological indicators were 18.95 cm for length,16.61 cm for width,2.35 cm for thickness,248.67 cm^2 for surface area,and 390.72 cm^3 for volume and all the indicators increased with the increment of newborn birth weight.After adjusting for confounding factors,the results of logistic regression indicated that smaller placenta length(odds ratio[OR]=2.15,95%confidence interval[95%CI]:1.46–3.15),width(OR=1.71,95%CI:1.17–2.50),surface area(OR=2.94,95%CI:2.08–4.16),and volume(OR=3.84,95%CI:2.01–4.01)were risk factors of small for gestational age(SGA);while greater placenta length(OR=0.48,95%CI:0.25–0.95)and surface area(OR=0.54,95%CI:0.29–0.99)were protective factors for SGA.In contrary,greater placenta length(OR=2.23,95%CI:1.66–2.99),width(OR=1.54,95%CI:1.14–2.09),thickness(OR=2.60,95%CI:1.92–3.54),surface area(OR=3.54,95%CI:2.69–4.65),and volume(OR=4.34,95%CI:3.28–5.75)were risk factors of large for gestational age(LGA);but smaller placenta width(OR=0.38,95%CI:0.24–0.61),surface area(OR=0.43,95%CI:0.27–0.70),and volume(OR=0.48,95%CI:0.29–0.78)were protective factors of LGA.The effect of smaller placenta width on the risk of SGA,greater placenta width on the risk of LGA,and smaller placenta volume on the risk of LGA were only observed among the pregnant women giving birth to male,female,and male infants.Conclusion The size of the placenta is closely related to intrauterine growth and is influenced by the sex of the fetus.