Kist Willem J, Janssen Nard G, Kalk Jakoba J, Hague William M, Dekker Gustaaf A, de Vries Johanna I P
Department of Obstetrics and Gynaecology, VU University Medical Centre, Amsterdam, The Netherlands.
Thromb Haemost. 2008 Jan;99(1):77-85. doi: 10.1160/TH07-05-0373.
It was the objective of this study to analyse the influence of confounders, such as ethnicity, severity of illness and method of testing, in articles concerning the still moot relationship of thrombophilias to adverse pregnancy outcome (APO). Relevant case-control studies were identified using Medline and EMBASE databases between 1966 and 2006. Search terms were recurrent fetal loss, intrauterine fetal death, preeclampsia, HELLP-syndrome, eclampsia, fetal growth restriction, abruptio placentae, combined with maternal thrombophilias. Data was extracted from the articles per subgroup of APO regardless of confounder. These subgroups were tested if they fulfilled the heterogeneity testing criterion (I(2) > 35%) to weigh the influence of the confounder. Confounders were selected and examined with Mantel-Haenszel method. Increased thrombophilia prevalence was confirmed in most adverse pregnancy outcomes. Ethnicity, genetic testing only and severity of illness were confounders in the various forms of APO. Stronger relationships between factor V Leiden and severity of disease were found in 2(nd) and 3(rd) trimester than 1(st) trimester recurrent fetal loss, in preeclampsia with: blood pressure > or =160/110 mmHg than > or =140/90 mmHg; proteinuria > or =5 grams per day than <5 grams; onset before than after 28 weeks, in fetal growth restriction <3(rd) percentile than <5(th), than <10(th), and in earlier occurrence of abruptio placentae than 3(rd) trimester. In conclusion, reports on the prevalence of maternal thrombophilias and APO are influenced by various confounders, which are not always appropriately analysed. The differences we have identified reflect the differential impact of these confounders. These data emphasise the importance of more uniform research.
本研究的目的是分析混杂因素（如种族、疾病严重程度和检测方法）对有关血栓形成倾向与不良妊娠结局（APO）之间仍有争议关系的文章的影响。利用1966年至2006年间的Medline和EMBASE数据库识别相关病例对照研究。检索词为复发性胎儿丢失、宫内胎儿死亡、先兆子痫、HELLP综合征、子痫、胎儿生长受限、胎盘早剥，并与母亲血栓形成倾向相结合。无论混杂因素如何，均从APO的每个亚组文章中提取数据。对这些亚组进行检验，看其是否符合异质性检验标准（I(2)>35%），以权衡混杂因素的影响。选择混杂因素并用Mantel-Haenszel方法进行检验。在大多数不良妊娠结局中，血栓形成倾向患病率增加得到证实。种族、仅基因检测和疾病严重程度是各种形式APO的混杂因素。在孕中期和孕晚期发现因子V Leiden与疾病严重程度之间的关系比孕早期复发性胎儿丢失更强，在先兆子痫中：血压≥160/110 mmHg比≥140/90 mmHg；蛋白尿≥5克/天比<5克；发病在28周之前比之后；在胎儿生长受限中，低于第3百分位数比低于第5百分位数、低于第10百分位数，以及在胎盘早剥较早发生比孕晚期。总之，关于母亲血栓形成倾向患病率和APO的报告受到各种混杂因素的影响，而这些因素并不总是得到适当分析。我们所确定的差异反映了这些混杂因素的不同影响。这些数据强调了更统一研究的重要性。
