biostudies-literatureCostantine MMEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Center for Research ResourcesNICHD NIH HHSNCATS NIH HHSNCRR NIH HHSNational Institutes of Health181.e1-181.e11https://www.ebi.ac.uk/biostudies/studies/S-EPMC8328864biostudies-literatureUnknown225(2)<h4>Background</h4>Short cervix at midgestation, the presence of intraamniotic debris, and cervical funneling are risk factors for preterm birth; however, cervical length measurements and cutoffs are not well documented among pregnant patients of different gestational ages and self-reported races and ethnicities.<h4>Objective</h4>This study aimed to describe the distribution of cervical length and frequency of funneling and debris at midgestation in nulliparous women by gestational age and race/ethnicity.<h4>Study design</h4>This secondary analysis of screening data from a multicenter treatment trial of singleton nulliparous patients with short cervix was conducted at 14 geographically distributed, university-affiliated medical centers in the United States. Singleton nulliparous patients wAmerican journal of obstetrics and gynecologyCervical length distribution and other sonographic ancillary findings of singleton nulliparous patients at midgestation.PMC8328864U10 HD040485HD40485U10 HD040560U24 HD036801HD40560HD34208U10 HD053118U10 HD034208UL1 RR025764HD27915HD21410HD27917U10 HD027869UL1 RR024153U10HD36801HD40512U10 HD027915U10 HD027917HD34116UL1 TR002548UL1 TR000005U10 HD034116UG1 HD053097HD53097UG1 HD040544UG1 HD040500UG1 HD040545U10 HD021410HD27869U10 HD040512HD40544HD40500HD40545UG1 HD027869U10 HD036801UG1 HD034116U10 HD053097UG1 HD040512U10 HD040500U10 HD040544U10 HD040545UG1 HD027915M01 RR00080M01 RR000080UL1 RR024989P2C HD050924HD53118UG1 HD0342085UL1RR025764UG1 HD040485UG1 HD040560Duquette CSenka JGerwig LClark KRusso JFlores CPena-Centeno KTolosa JEHauff NDinsmoor MBlackwell SCBenezue RIams JCline DGilbert SSegel SNowinski DHoffman MHill KHunt JKingsbery JMoran CZubic RButcher SBirkland MHLatimer CWeaver ADotson TThorp JMLake MTocci CSorokin YMoseley LLynch SRicon MMilluzzi CAcosta RFrantz SRech BMyers SNorthen ATita ATNVanDorsten JPShubert PPeaceman ALozitska ATillinghast JBousleiman SSpong CFyffe SOrtiz FMallett GRouse DJAlexander SMiller JGrobman WAEunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units NetworkGrant JMiller RReed PBethelemy MKing MUgwu LThom EDalton WNorman GVarner MWCotroneo PCaritis SNJohnson FAndrews WRanzini ARouse DWapner RJGardner DGivens PBludau VDorman KWaters TPereira LDashe JAllen DPlante LEsplin MSMercer BMSimhan HAllard DSmith TSheppard JThompson-Garbrecht DTimlin STolivaisa SLeveno KSmith WCostantine MMfalseCervical length distribution and other sonographic ancillary findings of singleton nulliparous patients at midgestation.<h4>Background</h4>Short cervix at midgestation, the presence of intraamniotic debris, and cervical funneling are risk factors for preterm birth; however, cervical length measurements and cutoffs are not well documented among pregnant patients of different gestational ages and self-reported races and ethnicities.<h4>Objective</h4>This study aimed to describe the distribution of cervical length and frequency of funneling and debris at midgestation in nulliparous women by gestational age and race/ethnicity.<h4>Study design</h4>This secondary analysis of screening data from a multicenter treatment trial of singleton nulliparous patients with short cervix was conducted at 14 geographically distributed, university-affiliated medical centers in the United States. Singleton nulliparous patients w2021-01-01T00:00:00Z2021 Aug2025-04-22T11:32:47.508Z2025-04-05T23:58:49.345ZS-EPMC83288643361779710.1016/j.ajog.2021.02.017