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The influence of neonatal birth weight on postpartum pelvic floor function in primiparas
Ying Zhou1,2, Dan Wu3, Qian Zhu2
1Department of Obstetrics and Gynecology, Jiangning Clinical Medical Hospital College, Kangda College of Nanjing Medical University, Nanjing, Jiangsu, China.
Insights
Higher infant birth weight is linked to increased risk of pelvic floor dysfunction (PFD) in new mothers. This impacts bladder control and prolapse, persisting even a year after childbirth.
Area of Science:
- Obstetrics and Gynecology
- Pelvic Floor Health
- Maternal-Fetal Medicine
Background:
- Pelvic floor dysfunction (PFD) is a common postpartum complication affecting women's quality of life.
- Risk factors for PFD are multifactorial, with birth weight emerging as a potential contributor.
- Understanding the impact of infant birth weight on maternal pelvic floor health is crucial for preventative strategies.
Purpose of the Study:
- To investigate the association between infant birth weight and the incidence of PFD in primiparas.
- To evaluate the long-term effects of higher birth weight on pelvic floor function at 42 days and 1 year postpartum.
- To identify specific ultrasound and electromyography parameters indicative of PFD related to birth weight.
Main Methods:
- Retrospective analysis of 200 primiparas with full-term vaginal deliveries.
- Categorization into study (3500-3999g) and control (2500-3499g) groups based on infant birth weight.
- Pelvic floor evaluation using ultrasound and surface electromyography (sEMG) at 6-8 weeks and 1 year postpartum.
Main Results:
- Higher birth weight group showed increased incidence of stress urinary incontinence, bladder prolapse, and uterine prolapse at 42 days postpartum.
- Significant differences in sEMG assessments were observed between groups at both time points.
- Ultrasound revealed impaired bladder neck support and increased levator hiatus area in the higher birth weight group, persisting at 1 year postpartum.
Conclusions:
- Higher infant birth weight is a significant risk factor for developing postpartum pelvic floor dysfunction.
- Elevated birth weight is associated with persistent impairments in pelvic floor function and structural integrity.
- Early identification and management of women with higher birth weight infants may help mitigate PFD risk.
Abstract:
This study aims to investigate the effect of birth weight on the incidence of pelvic floor dysfunction (PFD) in primiparas at 42 days and 1-year postpartum, using pelvic floor ultrasound and surface electromyography (sEMG). A retrospective analysis was conducted on 200 primiparas women who had a full-term vaginal delivery. All participants underwent pelvic floor evaluation at 6 to 8 weeks postpartum, with a follow-up at 1 year. The primiparas were categorized into 2 groups based on infant birth weight: a study group (n = 100, 3500 g ≤ birth weight <4000 g) and a control group (n = 100, 2500 g ≤ birth weight <3500 g). Significant differences were observed in prenatal body mass index, duration of the second stage of labor, incidence of gestational diabetes, perineal laceration, and episiotomy between the 2 groups (P <.05). At 42 days postpartum, the study group had significantly higher incidence rates of stress urinary incontinence, bladder prolapse, and uterine prolapse compared to the control group (P <.05). However, at 1-year postpartum, only the differences in the incidence of bladder prolapse and stress urinary incontinence remained statistically significant (P <.05). The sEMG assessment revealed significant differences in all 5 measured characteristics between the 2 groups at both 42 days and 1-year postpartum (P <.05). Ultrasound findings among PFD primiparas showed that, at 42 days postpartum, the study group had smaller bladder neck-symphaseal distance in the resting state and maximum Valsalva state (R-BSD and V-BSD), and greater bladder neck descent (BND), urethral rotation angle, and 1evator hiatus area in maximum Valsalva state (V-LHA) than the control group (P <.05). At 1 year, differences in V-BSD, BND, urethral rotation angle, and V-LHA remained significant. Among primiparas without PFD, significant differences were only found in V-BSD, BND, and V-LHA at both time points (P <.05). Higher birth weight is associated with impaired postpartum pelvic floor function and may be a significant risk factor for PFD.
