Bagandanshwa Kenneth, Mchome Bariki, Kibona Upendo, Gaffur Raziya, Salum Ibrahim, Kavishe Adelaida, Mushi Cecilia, Mlay Pendo, Masenga Gileard, Egenberg Signe, Eggebø Torbjørn Moe
Department of Obstetrics and Gynecology, Kilimanjaro Christian Medical University College, Moshi, Tanzania.
Department of Obstetrics and Gynecology, Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
Acta Obstet Gynecol Scand. 2025 Jan;104(1):225-234. doi: 10.1111/aogs.15013. Epub 2024 Nov 20.
Occiput posterior (OP) position rates at birth are 5%-8% in studies mainly comprising white European women. The anthropoid pelvis is common in black African women. This pelvic shape has a narrow anterior segment and an ample room posteriorly. The fetal head is wider posteriorly, and the OP position may be favorable in women with an anthropoid pelvic shape. We aimed to examine the fetal rotation with ultrasound longitudinally during the active phase of labor in a sub-Saharan population. We also aimed to examine associations between fetal position, delivery mode, and duration of labor.
The study was conducted at Kilimanjaro Christian Medical Centre in Moshi, Tanzania from the 19th of November 2023 to 13th of April 2024. Women with a single fetus in cephalic presentation, gestational age >37 weeks, without previous or pre-labor cesarean section were eligible. Fetal position was classified as occiput anterior (OA) from 10 to 2 o'clock, occiput transverse (OT) at 3 or 9 o'clock, and OP position from 4 to 8 o'clock.
The study participants comprised 215 women. Fetal positions at admission, in the first and second stage of labor and at birth are presented in the graphical figure. In all, 65/215 (30.2%) fetuses were in OP position at admission, 59/204 (28.9%) in the first stage, 38/210 (18.1%) in the second stage and 35/215 (16.3%) were delivered in OP position. The OP rates at birth were 25/92 (27.2%) in nulliparous and 10/123 (8.1%) in parous women. The operative delivery rate was 10/157 (6.4%) in women with ultrasound assessed fetal position as OA in the second stage (six cesarean section and four vacuum extractions), and 28/48 (58.3%) in the non-OA group (27 cesarean section and one vacuum extraction) (p < 0.01). The hazard ratio for delivery in the second stage was 0.26 (95% CI 0.13-0.52) for the non-OA vs the OA group in nulliparous women and 0.25 (95% CI 0.12-0.52) in parous women.
The persistent OP position rate at birth was higher than previously reported, and the operative intervention rate was nine time higher in women with the fetus in non-OA vs OA position in the second stage.
在主要纳入欧洲白人女性的研究中，枕后位（OP）的出生发生率为5%-8%。类人猿型骨盆在非洲黑人女性中较为常见。这种骨盆形状前侧狭窄而后侧空间充足。胎儿头部后侧较宽，因此类人猿型骨盆的女性可能更有利于枕后位。我们旨在纵向超声检查撒哈拉以南地区人群分娩活跃期的胎儿旋转情况。我们还旨在研究胎儿位置、分娩方式和产程之间的关联。
该研究于2023年11月19日至2024年4月13日在坦桑尼亚莫希的乞力马扎罗基督教医疗中心进行。单胎头先露、孕周>37周、既往无剖宫产史或临产前未行剖宫产的女性符合纳入标准。胎儿位置分类如下：枕前位（OA）为10点至2点，枕横位（OT）为3点或9点，枕后位为4点至8点。
研究参与者包括215名女性。入院时、第一产程和第二产程以及出生时的胎儿位置情况见图表。总体而言，215例中有65例（30.2%）胎儿入院时为枕后位，204例中有59例（28.9%）在第一产程为枕后位，210例中有38例（18.1%）在第二产程为枕后位，215例中有35例（16.3%）以枕后位分娩。初产妇的出生枕后位发生率为25/92（27.2%），经产妇为10/12（8.1%）。超声评估第二产程胎儿位置为枕前位的女性手术分娩率为10/157（6.4%）（6例剖宫产和4例真空吸引助产），非枕前位组为28/48（58.3%）（27例剖宫产和1例真空吸引助产）（p<0.01）。初产妇中，第二产程非枕前位组与枕前位组相比的分娩风险比为0.26（95%CI 0.13-0.52），经产妇为0.25（95%CI 0.12-0.52）。
出生时持续枕后位发生率高于先前报道，第二产程胎儿为非枕前位与枕前位的女性相比，手术干预率高出9倍。
