1074 Cervical length nomogram in hispanic patients

Abstract

Most of the studies have been done on the general population and none targeted special populations. The studies on transvaginal ultrasound cervical length (TVUCL) included patients with various ethnicities. There are reports that CL differs by race and ethnicity. The aim of this study was to develop a TVUCL normogram in low risk pregnant Hispanic women. All TVUCL measurements performed between December 2016 and December 2018 at a single tertiary care institution were reviewed. We included all patients who self-identified as Hispanic, were between the ages of 18 to 45 years, had singleton pregnancies, and underwent universal TVUCL between 16-24 weeks of gestation. We excluded patients with twin or higher order pregnancies, uterine anomalies or cerclage placement at time of screening or with history of preterm birth. We collected demographic data, gravidity, parity, gestational age at time of cervical length screen and cervical length. Cervical length across gestation was analyzed by the LMS method. A thousand patients were included in the analysis (Table 1). Nomogram is shown in Figure 1A. The 50th, 10th and 5th percentiles TVUCLs were 4.01 cm, 3.23 cm, and 3 cm, respectively (Table 2). Compared with those who delivered at term (>37 weeks), patients who had spontaneous preterm birth (sPTB) had shorter TVUCL (mean difference (MD): 0.57cm, 95%CI 0.25-0.89; Figure 1B), but those with medically indicated preterm delivery did not (MD: -0.06cm, 95%CI -0.25-0.13; Figure 1C). Among preterm deliveries, only deliveries below 28 weeks had significantly shorter cervix (MD: 0.99cm, 95%CI (0.21- 1.77)) compared to patients who delivered more than 28 weeks. Receiver operating characteristic curve analysis revealed that for a clinically relevant positive likelihood ratio, a TVUCL cutoff of 3.08cm was best in predicting sPTB (Table 3). The nomogram for TVUCL in Hispanic low risk pregnant women shows longer CL than previously reported. If validated in other studies, a higher cutoff may need to be used to define short cervix in Hispanics.View Large Image Figure ViewerDownload Hi-res image Download (PPT)