Why do nulliparous teenagers have the highest rate of unassisted vaginal deliveries compared to their older counterparts?
Objectives To establish why teenagers (13–19 years old) primiparas have higher rates of unassisted vaginal deliveries compared with their older counterparts.Methods University’s maternity, 24.5-year-observational population-based cohort study (2001–2024). All consecutive nulliparous singleton pregna...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2025-12-01
|
| Series: | The Journal of Maternal-Fetal & Neonatal Medicine |
| Subjects: | |
| Online Access: | https://www.tandfonline.com/doi/10.1080/14767058.2025.2503509 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Objectives To establish why teenagers (13–19 years old) primiparas have higher rates of unassisted vaginal deliveries compared with their older counterparts.Methods University’s maternity, 24.5-year-observational population-based cohort study (2001–2024). All consecutive nulliparous singleton pregnancies. Analysis of the main indications for cesarean sections (c-sections) and also need for operative vaginal procedures of all nulliparous pregnant women with an age range from 14 to 40+ yrs.Results Out of 33,785 singleton primiparous livebirth pregnancies, vaginal births represented 91% at the ages 14–15 dropping to just 55% at ≥40 yrs. The rate of c-sections was 9% at the ages 14–15, increasing to a rate of 45% at ≥40 years. Operative vaginal delivery rate was 12.1% at the ages 14–15 years, versus 29.8% at ≥ t 40 years (both χ2 for trend, p < .0001). Two-thirds of the indications for c-sections were “abnormal fetal monitoring” (AFM) and “Obstructed Labor” (OL). The indication AFM had a χ2 for a negative linear trend p = .0004: a high rate of 39% for the ages 14–15, and 25% for the ages over 40 years. The indication OL had a positive trend with maternal ages but not linear (p = .13): 17% for the ages 14–15 years, 25% for the ages 16–19, followed by a plateau around 32% between 20 and 40 years.Conclusions Vaginal births in primiparas without obstetrical assistance occur preferably at younger ages with a regular negative linear trend, p < .001 until the ages 40+. The indication AFM for c-sections also had a negative linear trend, p = .0004, while OL as indication for c-sections represented a minority in teenagers (below breech presentation). In teenagers, the higher rate of unassisted vaginal births may be due to an intrinsic biologic cause (uterine contractility). |
|---|---|
| ISSN: | 1476-7058 1476-4954 |