Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 USA; Department of Anthropology, University of Washington, Box 353100, Seattle, WA 98195 USA.
Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 USA; Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., PO Box 19024, Seattle, WA 98109 USA.
Semin Arthritis Rheum. 2020 Feb;50(1):1-6. doi: 10.1016/j.semarthrit.2019.06.011. Epub 2019 Jun 18.
Rheumatoid arthritis (RA) often ameliorates during pregnancy and flares postpartum, but the relationship of pregnancy and childbirth to RA prognosis is unclear. We examined RA severity for association with parity prior to RA onset and asked whether time from birth (latency) and/or the mother's HLA genotype influenced results.
A cohort study was conducted of 222 women previously identified in a prospective study of newly diagnosed RA, who returned for follow-up evaluation a median of 8 years later. Stratified analyses using Mantel-Haenszel methods were conducted to evaluate 5 RA severity measures based on hand and wrist radiographs, physical exams, and Health Assessment Questionnaires for association with parity.
Overall, we observed little evidence of altered risk of progression to severe RA in relation to pre-onset parity, adjusting for RA onset age and time to follow-up. Stratifying parous women who had only live births by latency (<15 years/15+ years) showed no difference in risk of severe RA compared to nulligravid women. Live birth deliveries were significantly protective for women with 0 but not for those with 1 or 2 copies of the RA risk-associated HLA-DRB1 shared epitope sequence for erosion score (RR 0.26 95% CI 0.09-0.89) and joint count (RR 0.28 95% CI 0.09-0.87).
We observed little evidence of difference in severe RA by pre-onset parity overall. However, among women not predisposed to RA by possessing the risk-associated HLA genotype, parous women who had only live births had lower risk of progression to severe RA as measured by erosion score and joint count.
类风湿关节炎（RA）在妊娠期间通常会缓解，产后会加重，但妊娠和分娩与 RA 预后的关系尚不清楚。我们检查了 RA 严重程度与发病前的生育次数的关系，并询问了分娩时间（潜伏期）和/或母亲的 HLA 基因型是否影响结果。
对 222 名先前在一项新诊断 RA 的前瞻性研究中确定的女性进行了队列研究，这些女性在中位时间为 8 年后返回进行随访评估。采用 Mantel-Haenszel 方法进行分层分析，根据手部和腕部 X 线片、体格检查和健康评估问卷，评估 5 种 RA 严重程度指标与生育次数的关系。
总体而言，我们发现，在调整 RA 发病年龄和随访时间后，发病前生育次数与进展为严重 RA 的风险几乎没有关联。对仅生育活产的多产妇进行分层，与未生育的女性相比，潜伏期<15 年/15 年的女性发生严重 RA 的风险没有差异。对于 HLA-DRB1 共享表位序列为侵蚀评分（RR 0.26 95%CI 0.09-0.89）和关节计数（RR 0.28 95%CI 0.09-0.87）的风险相关 HLA 基因型无差异的女性，活产分娩具有显著保护作用。
我们发现总体上发病前生育次数与严重 RA 无差异。然而，在没有携带风险相关 HLA 基因型而容易发生 RA 的女性中，仅生育活产的多产妇发生严重 RA 的风险较低，这是通过侵蚀评分和关节计数来衡量的。
