Fetal descent in nulliparous women assessed by ultrasound: a longitudinal study.

• Published in: American Journal of Obstetrics and Gynecology
• Main Authors: Hjartardóttir, Hulda, Lund, Sigrún H, Benediktsdóttir, Sigurlaug, Geirsson, Reynir T, Eggebø, Torbjørn M
• Other Authors: 1Department of Obstetrics and Gynecology, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland; Faculty of Medicine, University of Iceland, Reykjavik, Iceland. Electronic address: [e-mail]. 2deCODE genetics, Reykjavik, Iceland. 3Department of Obstetrics and Gynecology, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland; Faculty of Medicine, University of Iceland, Reykjavik, Iceland. 4National Center for Fetal Medicine, Department of Obstetrics and Gynecology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; Department of Obstetrics and Gynecology, Stavanger University Hospital, Stravanger, Norway; Institute of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: angle of progression; cesarean delivery; fetal head position; fetal head station; head-perineum distance; transabdominal ultrasound; transperineal ultrasound; Fæðingarlækningar; Ómskoðun; Labor Presentation; Ultrasonography; Iceland
• Online Access: http://hdl.handle.net/2336/621827; https://doi.org/10.1016/j.ajog.2020.10.004

To access publisher's full text version of this article click on the hyperlink below Background: Ultrasound measurements offer objective and reproducible methods to measure the fetal head station. Before these methods can be applied to assess labor progression, the fetal head descent needs to be evaluated longitudinally in well-defined populations and compared with the existing data derived from clinical examinations. Objective: This study aimed to use ultrasound measurements to describe the fetal head descent longitudinally as labor progressed through the active phase in nulliparous women with spontaneous onset of labor. Study design: This was a single center, prospective cohort study at the Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland, from January 2016 to April 2018. Nulliparous women with a single fetus in cephalic presentation and spontaneous labor onset at a gestational age of ≥37 weeks, were eligible. Participant inclusion occurred during admission for women with an established active phase of labor or at the start of the active phase for women admitted during the latent phase. The active phase was defined as an effaced cervix dilated to at least 4 cm in women with regular contractions. According to the clinical protocol, vaginal examinations were done at entry and subsequently throughout labor, paired each time with a transperineal ultrasound examination by a separate examiner, with both examiners being blinded to the other's results. The measurements used to assess the fetal head station were the head-perineum distance and angle of progression. Cervical dilatation was examined clinically. Results: The study population comprised 99 women. The labor patterns for the head-perineum distance, angle of progression, and cervical dilatation differentiated the participants into 75 with spontaneous deliveries, 16 with instrumental vaginal deliveries, and 8 cesarean deliveries. At the inclusion stage, the cervix was dilated 4 cm in 26 of the women, 5 cm in 30 of the women, and ≥6 ...