Ornaghi Sara, Colciago Elisabetta, Montelisciani Laura, Arienti Francesca, Fernicola Federica, Abbamondi Alessandra, Giani Sofia, Fumagalli Simona, Antolini Laura, Vaglio Tessitore Isadora, Zangheri Giulia, Gatti Elena, Vignali Michele, Callegari Clelia, Sala Andrea, Plevani Cristina, Smid Maddalena, Pozzoni Mirko, Castoldi Maria, Benedetti Sara, Meroni Mario G, Bulfoni Camilla, Catalano Anna, Consonni Sara, Fichera Anna, Fabbri Elisa, Vergani Patrizia, Locatelli Anna
Unit of Obstetrics, Foundation IRCCS San Gerardo dei Tintori, the University of Milan-Bicocca, School of Medicine and Surgery, and the 4 Center of Bioinformatics, Biostatistics, and Bioimaging, School of Medicine and Surgery, University of Milan-Bicocca, Monza, the Unit of Obstetrics and Gynecology, Vittorio Emanuele III Hospital, ASST Brianza, Carate Brianza, the Unit of Obstetrics and Gynecology, Macedonio Melloni Hospital, ASST Fatebenefratelli Sacco, the Unit of Obstetrics and Gynecology, IRCCS San Raffaele Scientific Institute, Vita-Salute San Raffaele University, the Unit of Obstetrics and Gynecology, ASST Grande Ospedale Metropolitano Niguarda, and the Unit of Obstetrics and Gynecology, Vittore Buzzi Hospital, ASST Fatebenefratelli Sacco, University of Milan, School of Medicine and Surgery, Milan, the Unit of Obstetrics and Gynecology, Alessandro Manzoni Hospital, ASST Lecco, Lecco, the Unit of Obstetrics and Gynecology, Poliambulanza Foundation Hospitals, and the Unit of Obstetrics and Gynecology, Spedali Civili Hospital, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
O G Open. 2024 Nov 7;1(4):42. doi: 10.1097/og9.0000000000000042. eCollection 2024 Dec.
To evaluate whether individuals who have a placenta previa or low-lying placenta that resolves before delivery are at increased risk of postpartum hemorrhage and postpartum hemorrhage-related morbidity.
This was a prospective, multicenter, 1:3 matched cohort study of pregnant individuals with singleton gestations diagnosed with low placentation by transvaginal scan at 19 to 23 weeks of gestation between January 2021 and December 2023 at nine academic maternity centers (exposed participants). Unexposed participants were those with a normally located placenta, matched in a 1:3 ratio according to parity. Resolution of low placentation was diagnosed when placenta was at 20 mm or more from the internal os. Individuals with fetal anomalies, hematologic disorders, therapeutic anticoagulation, placenta accreta spectrum disorder, vasa previa, persistent low placentation at birth, and delivery at a nonenrolling center were excluded. Primary outcome was postpartum hemorrhage of 1,000 mL or more. Secondary outcomes included postpartum hemorrhage of 1,500 mL or more, use of second-line uterotonic drugs, blood transfusions, additional procedures to control bleeding, intensive care unit admission, and hospital stay for more than 7 days. Multivariable logistic regression adjusted for confounders was used to estimate independent associations with outcomes.
The study population included 182 exposed and 589 unexposed participants. Individuals with resolved low placentation had higher rates of smoking (=.024), prior dilation and curettage (=.012), posterior placenta (<.001), and induction of labor (=.038). Multivariate logistic regression analysis adjusted for confounders showed that exposed people had higher odds of postpartum hemorrhage of 1,000 mL or more (13.2% vs 4.1%, adjusted odds ratio [aOR] 3.1) compared with unexposed people and of use of second-line uterotonic drugs (28.0% vs 12.4%, aOR 2.69) and tranexamic acid (16.5% vs 7.5%, aOR 2.19), as well as hospital stay longer than 7 days (11.5% vs 3.4%, aOR 2.63).
Individuals with resolved low placentation are at increased risk of postpartum hemorrhage and related complications compared with those who always had a normally located placenta.
