BACKGROUND AND PURPOSE:

• Epidemiology studies have demonstrated associations between pelvic floor disorders and childbirth
  • More common with higher parity in vaginal vs cesarean delivery
• Less well known is relationship between maternal/obstetrical history and pelvic disorders over time
• Blomquist et al. (JAMA, 2018) sought to identify an association between maternal/obstetrical characteristics and pelvic floor disorders in the decades after delivery

METHODS:

• Data were derived from the Mother’s Outcome after Delivery (MOAD) study
  • Cohort study (longitudinal) of women after their first delivery (index birth)
  • Follow-up yearly for up to 9 years
  • Recruitment was based on mode of delivery and age matched controls
• Participants were divided in to one of the following exposures
  • Cesarean birth
  • Spontaneous vaginal birth
  • Operative vaginal birth (vacuum or forceps)
• Data on covariates were also collected to adjust risk
• The primary outcome
  • Stress urinary incontinence (SUI)
  • Overactive bladder (OAB)
  • Anal incontinence (AI)
  • pelvic organ prolapse (POP)
• In addition, the researchers assessed genital hiatus size using POP-Q
  • Distance (cm) from the middle of the external urethral meatus to the posterior midline hymen
  • Measured during the maximal Valsalva maneuver

RESULTS:

• 1,528 women were included
  • 778 cesarean group | 565 spontaneous vaginal group | 185 operative vaginal group
  • The median age at delivery: 30.6 years

Spontaneous vaginal delivery

• Estimated 5-year cumulative incidences following first delivery
  • SUI: 11.1% (95% CI, 8.7%-13.5%)
  • OAB: 4.8% (95% CI, 3.3%-6.3%)
  • AI: 8.5% (95% CI, 6.4%-10.5%)
  • POP: 1.6% (95% CI, 0.9%-2.3%)

Spontaneous vaginal delivery

• Estimated 15-year cumulative incidences after first delivery
  • SUI: 34.3% (95% CI, 29.9%-38.6%)
  • OAB: 21.8% (95% CI, 17.8%-25.7%)
  • AI: 30.6% (95% CI, 26.4%-34.9%)
  • POP: 30.0% (95% CI, 25.1%-34.9%)

Compared with spontaneous vaginal delivery

• Cesarean delivery was associated with significantly lower risk for
  • SUI: Adjusted hazard ratio (aHR) 0.46 (95% CI, 0.32-0.67)
  • OAB: aHR 0.51 (95% CI, 0.34-0.76)
  • POP: aHR, 0.28 (95% CI, 0.19-0.42)
• Operative vaginal delivery was associated with significantly higher risk for
  • AI: aHR 1.75 (95% CI, 1.14-2.68)
  • POP: aHR 1.88 (95% CI, 1.28-2.78)
• Compared to a genital hiatus size ≤2.5 cm
  • Genital hiatus size of 3cm: POP aHR was 3.0 (95% CI, 1.7-5.3)
  • Genital hiatus size ≥3.5 cm: POP aHR was 9.0 (95% CI, 5.5-14.8)

CONCLUSION:

• Compared to spontaneous vaginal delivery
  • Ceserean delivery was associated with reduced risk for pelvic floor disorders over time
  • Operative vaginal delivery was associated with a higher risk of anal incontinence and pelvic organ prolapse
• A larger genital hiatus was linked to increased risk of pelvic organ prolapse independent of delivery mode
• POP, compared to SUI and AI, will take longer to manifest following delivery
  • The authors suggest this is in keeping with possible mechanism of levator ani muscle injury which will ‘evolve over decades’
  • Urethral sphincter injury may occur with vaginal delivery and therefore SUI would have a shorter latency period from time of delivery

Learn More – Primary Sources:

Association of Delivery Mode With Pelvic Floor Disorders After Childbirth

Related ObG Topics:

Urinary Incontinence – How to Make the Diagnosis in Your Office and When to Refer

In Twin Pregnancies, Does Cesarean vs Vaginal Delivery Impact Postpartum Urinary Incontinence?

Mesh and Pelvic Organ Prolapse: ACOG Practice Advisory & ACOG/AUGS Recommendations