Harel Ziv, Park Alison L, Ray Joel G
Division of Nephrology, St. Michael's Hospital, Toronto, ON, Canada.
ICES, Toronto, ON, Canada.
Can J Kidney Health Dis. 2021 Oct 26;8:20543581211035221. doi: 10.1177/20543581211035221. eCollection 2021.
Glomerular hyperfiltration is one physiological adaptation to pregnancy, marked by a decline in serum creatinine (SCr) concentration by 16 weeks' gestation. It is not known whether blunted glomerular hyperfiltration leads to adverse maternal outcomes, including severe maternal morbidity (SMM).
To evaluate the association between blunted glomerular hyperfiltration and subsequent SMM or death.
Population-based cohort study.
Ontario, Canada, from 2008 to 2019.
Included were births among women who had ≥ 1 SCr measured as an outpatient within 10 weeks before conception ("preconception"), and again, at 11 to 20 weeks' gestation ("in-pregnancy"). Excluded were women who died before birth, who had end-stage renal disease or kidney transplantation before conception, or whose pre-pregnancy SCr was 125 μmol/L.
Net glomerular hyperfiltration defined as the preconception minus the in-pregnancy SCr.
The primary study outcome was SMM or death arising from 23 weeks' gestation up to 42 days after the index birth.
Adjusted relative risks (aRRs) were calculated using Modified Poisson regression per 1-SD net blunting of glomerular hyperfiltration adjusting for important covariates.
A total of 10,323 births met all inclusion criteria. The mean (SD) SCr was 61.7 (11.0) μmol/L preconception, 48.0 (9.2) μmol/L in-pregnancy, and the mean net difference 13.6 (8.2) μmol/L. Among these births, the adjusted RR of SMM or death from 23 weeks' gestation up to 42 days post-partum was 1.16 (95% confidence interval 1.14-1.30) per 1-SD (8.2 μmol/L) net blunting of glomerular hyperfiltration.
As SCr assessment is not a routine part of pregnancy care, its measurement could have been for a specific health condition thereby imparting selection bias.
Blunted glomerular hyperfiltration in pregnancy may identify some women at higher risk of SMM. Further prospective research is needed about the implications of glomerular hyperfiltration in early pregnancy.
肾小球高滤过是孕期的一种生理适应性变化，其特征为妊娠16周时血清肌酐（SCr）浓度下降。尚不清楚肾小球高滤过减弱是否会导致不良母体结局，包括严重母体发病（SMM）。
评估肾小球高滤过减弱与随后的SMM或死亡之间的关联。
基于人群的队列研究。
2008年至2019年期间的加拿大安大略省。
纳入在受孕前10周内（“受孕前”）作为门诊患者测量过≥1次SCr，且在妊娠11至20周时（“孕期”）再次测量过SCr的产妇分娩病例。排除在出生前死亡、在受孕前患有终末期肾病或接受过肾移植，或孕前SCr≥125μmol/L的女性。
净肾小球高滤过定义为受孕前SCr减去孕期SCr。
主要研究结局为从妊娠23周直至索引分娩后42天内发生的SMM或死亡。
使用修正泊松回归计算调整后的相对风险（aRRs），对肾小球高滤过每1标准差净减弱进行分析，并对重要协变量进行调整。
共有10323例分娩符合所有纳入标准。受孕前SCr的均值（标准差）为61.7（11.0）μmol/L，孕期为48.0（9.2）μmol/L，平均净差值为13.6（8.2）μmol/L。在这些分娩病例中，从妊娠23周直至产后42天，肾小球高滤过每1标准差（8.2μmol/L）净减弱，SMM或死亡的调整后RR为1.16（95%置信区间1.14 - 1.30）。
由于SCr评估并非孕期护理的常规组成部分，其测量可能是针对特定健康状况，从而产生选择偏倚。
孕期肾小球高滤过减弱可能识别出一些SMM风险较高的女性。需要对妊娠早期肾小球高滤过的影响进行进一步的前瞻性研究。
