Relationships of Risk Factors for Pre-Eclampsia with Patterns of Occurrence of Isolated Gestational Proteinuria during Normal Term Pregnancy

BackgroundIsolated gestational proteinuria may be part of the pre-eclampsia disease spectrum. Confirmation of its association with established pre-eclampsia risk factors and higher blood pressure in uncomplicated pregnancies would support this concept. MethodsData from 11,651 women from the Avon Longitudinal Study of Parents and Children who had a term live birth but did not have pre-existing hypertension or diabetes or develop gestational diabetes or preeclampsia were used. Proteinuria was assessed repeatedly (median 12 measurements per woman) by dipstick and latent class analysis was used to identify subgroups of the population with different patterns of proteinuria in pregnancy. ResultsHigher maternal pre-pregnancy body mass index (BMI), younger age, nulliparity and twin pregnancy were independently associated with increased odds of any proteinuria in pregnancy. Women who experienced proteinuria showed five patterns: proteinuria in early pregnancy only (≤20 weeks gestation), and onset at 21–28 weeks, 29–32 weeks, 33–36 weeks and ≥37 weeks gestation. There were higher odds of proteinuria onset after 33 weeks in obese women and after 37 weeks in nulliparous women compared with normal weight and multiparous women respectively. Smoking in pregnancy was weakly negatively associated with odds of proteinuria onset after 37 weeks. Twin pregnancies had higher odds of proteinuria onset from 29 weeks. In women with proteinuria onset after 33 weeks blood pressure was higher in early pregnancy and at the end of pregnancy. ConclusionsEstablished pre-eclampsia risk factors were related to proteinuria occurrence in late gestation in healthy term pregnancies, supporting the hypothesis that isolated gestational proteinuria may represent an early manifestation of pre-eclampsia.背景 孤立性妊娠期蛋白尿（gestational proteinuria）可能属于子痫前期（pre-eclampsia）疾病谱的范畴。确认其与已确立的子痫前期危险因素，以及无并发症妊娠人群中更高血压水平的关联，将为这一假说提供实证支撑。 方法 本研究使用来自雅芳父母与儿童纵向研究（Avon Longitudinal Study of Parents and Children）的11651名女性的数据，所有研究对象均足月活产，无既往高血压或糖尿病病史，且未发生妊娠期糖尿病或子痫前期。研究采用尿蛋白试纸法对蛋白尿进行反复检测（每名女性的检测次数中位数为12次），并通过潜类别分析（latent class analysis）识别妊娠期间蛋白尿表现存在差异的人群亚组。 结果 产妇孕前更高的体质指数（body mass index, BMI）、更年轻的年龄、初产以及双胎妊娠，均与妊娠期间出现任意类型蛋白尿的更高比值比独立相关。出现蛋白尿的女性可划分为5种发病模式：仅妊娠早期（≤孕20周）出现蛋白尿，以及分别于孕21~28周、29~32周、33~36周、≥37周出现蛋白尿。与体重正常女性相比，肥胖女性在孕33周后出现蛋白尿的比值比更高；与经产女性相比，初产女性在孕37周后出现蛋白尿的比值比更高。妊娠期吸烟与孕37周后出现蛋白尿的比值比呈弱负相关。双胎妊娠女性自孕29周起出现蛋白尿的风险显著升高。在孕33周后出现蛋白尿的女性中，妊娠早期及妊娠末期的血压水平均更高。 结论 在健康足月妊娠人群中，已明确的子痫前期危险因素与妊娠晚期蛋白尿的发生存在关联，这支持了孤立性妊娠期蛋白尿可能为子痫前期早期表现的假说。