Department of Epidemiology, Biostatistics, and Occupational Health, University of British Columbia, Vancouver; Department of Obstetrics & Gynecology, University of British Columbia, Vancouver.
Paediatr Perinat Epidemiol. 2014 Mar;28(2):97-105. doi: 10.1111/ppe.12104. Epub 2013 Dec 20.
Placental weight is an independent predictor of adverse perinatal outcome. However, risk factors for high and low placental weight are poorly understood. The objective of this study was to identify maternal, placental, and umbilical cord determinants of placental weight, before and after accounting for birthweight.
This cohort study of 87,600 singleton births at the Royal Victoria Hospital in Montreal, Canada assessed the relationship between maternal, placental, and umbilical cord characteristics and placental weight (standardised for sex and gestational age). We separately examined risk factors for high (z-score >+1) and low (z-score <-1) placental weight. Multivariable logistic regression was used to study associations after adjusting for confounders and further adjusting for birthweight.
Chronic hypertension was associated with low placental weight {relative risk (RR) 2.1 [95% confidence interval (CI) 1.8, 2.4] and 1.8 [95% CI 1.5, 2.1] before and after accounting for birthweight}, while pre-eclampsia was associated with low placenta weight before, but not after adjustment for birthweight. Anaemia and gestational diabetes were linked with high placental weight (RRs 1.2-1.4, respectively) before and after adjustment for birthweight, while smoking was linked with high placental weight only after adjustment for birthweight (RR 1.4 [95% CI 1.3, 1.5]). Placental and cord determinants of high placental weight included chorioamnionitis, chorangioma/chorangiosis, circumvallate placenta, marginal cord insertion, and other cord abnormalities.
The broad range of risk factors for high placental weight suggests multiple aetiologic pathways. Future work should seek to understand the pathways by which the placenta adapts to unfavourable intrauterine conditions, which may provide insights into potential therapies.
胎盘重量是不良围生结局的独立预测因素。然而，高、低胎盘重量的风险因素知之甚少。本研究的目的是在考虑出生体重后，确定胎盘重量的母体、胎盘和脐带决定因素。
这是一项在加拿大蒙特利尔皇家维多利亚医院进行的 87600 例单胎分娩的队列研究，评估了母体、胎盘和脐带特征与胎盘重量（按性别和胎龄标准化）之间的关系。我们分别检查了高（z 评分>+1）和低（z 评分<-1）胎盘重量的危险因素。多变量逻辑回归用于在调整混杂因素后进一步调整出生体重后研究相关性。
慢性高血压与低胎盘重量相关{相对风险（RR）2.1（95%置信区间（CI）1.8，2.4）和 1.8（95%CI 1.5，2.1），在考虑出生体重之前和之后}，而子痫前期与低胎盘重量相关，仅在调整出生体重后才相关。贫血和妊娠期糖尿病与高胎盘重量相关（分别为 RR 1.2-1.4），而吸烟仅在调整出生体重后与高胎盘重量相关（RR 1.4 [95%CI 1.3，1.5]）。高胎盘重量的胎盘和脐带决定因素包括绒毛膜炎、绒毛血管瘤/绒毛膜病、球拍状胎盘、边缘脐带插入和其他脐带异常。
高胎盘重量的危险因素范围广泛，提示存在多种病因途径。未来的工作应该寻求了解胎盘适应不利宫内环境的途径，这可能为潜在的治疗方法提供见解。
