Vanderbilt Epidemiology Center, Institute for Medicine and Public Health, Vanderbilt University Medical Center, 2525 West End Avenue, Nashville, TN, 37203, USA.
Women's Health Research at Vanderbilt, Vanderbilt University Medical Center, 2525 West End Avenue, Nashville, TN, 37203, USA.
BMC Pregnancy Childbirth. 2021 Aug 17;21(1):560. doi: 10.1186/s12884-021-03968-2.
Fibroids are present in approximately one in ten pregnancies and are inconsistently linked with preterm birth. We sought to determine the association between fibroids and preterm birth in a prospective cohort with standardized research ultrasounds for characterizing fibroids in early pregnancy while accounting for the clinical paths that precede preterm birth.
Participants who were pregnant or planning a pregnancy were recruited from communities in three states between 2000 and 2012. Members of this prospective cohort had a research ultrasound in the first trimester to establish pregnancy dating and to record detailed information about the presence, size, number, and location of fibroids. Baseline information from time of enrollment and a detailed first trimester interview contributed key information about candidate confounders. Birth outcomes, including clinical classification of type of preterm birth (preterm labor, preterm premature rupture of membranes, and medically indicated preterm birth) were cross-validated from participant report, labor and delivery records, and birth certificate data.
Among 4,622 women with singleton pregnancies, 475 had at least one fibroid (10.3%) and 352 pregnancies resulted in preterm birth (7.6%). Prevalence of fibroids was similar for women with preterm and term births (10.2% vs. 10.3%). Fibroids were not associated with increased risk of preterm birth after taking into account confounding (risk ratio adjusted for race/ethnicity and maternal age, 0.88; 95% confidence interval, 0.62-1.24) nor any clinical subtype of preterm birth. No fibroid characteristic or combination of characteristics was associated with risk.
If fibroids increase risk of preterm birth, the effect is substantially smaller than previous estimates. Given lack of effect in a large population of women from the general population, rather than higher risk academic tertiary populations previously most studied, we encourage a reconsideration of the clinical impression that presence of fibroids is a major risk factor for preterm birth.
子宫肌瘤在大约十分之一的妊娠中存在，与早产的关系不一致。我们旨在通过前瞻性队列研究来确定子宫肌瘤与早产之间的关联，该队列研究在妊娠早期进行了标准化的研究超声检查，以描述子宫肌瘤的特征，同时考虑到导致早产的临床路径。
该前瞻性队列的参与者于 2000 年至 2012 年期间在三个州的社区招募，在妊娠早期进行研究超声检查以确定妊娠日期，并记录子宫肌瘤的存在、大小、数量和位置的详细信息。在招募时的基线信息和详细的早孕访谈为候选混杂因素提供了关键信息。分娩结局，包括早产的临床分类（早产临产、早产胎膜早破和医学指征性早产），通过参与者报告、分娩和分娩记录以及出生证明数据进行交叉验证。
在 4622 名单胎妊娠妇女中，有 475 名妇女至少有一个子宫肌瘤（10.3%），有 352 例妊娠导致早产（7.6%）。患有早产和足月产的妇女的子宫肌瘤患病率相似（10.2%与 10.3%）。在考虑混杂因素后，子宫肌瘤与早产风险增加无关（经种族/民族和产妇年龄调整的风险比为 0.88；95%置信区间为 0.62-1.24），也与任何类型的早产无关。没有子宫肌瘤特征或特征组合与风险相关。
如果子宫肌瘤增加早产的风险，其影响远小于之前的估计。鉴于在来自普通人群的大量妇女中没有影响，而不是以前研究最多的风险更高的学术三级人群，我们鼓励重新考虑子宫肌瘤存在是早产的主要危险因素的临床印象。
