Carbon monoxide disposition and permeability-surface area product in the foetal circulation of the perfused term human placenta

In order to estimate the placental barrier to gas transfer, a novel carbon monoxide (CO) wash-in method was used to estimate the permeability-surface area (PS) product for the transfer of gas across the foetal circulation in the perfused human term placenta. The PS product for CO was 0.0096+/-0.006 ml/s/g or 0.012+/-0.007 ml/s/g using compartmental or Crone-Renkin analysis, respectively. Using this result and a published estimate of the placental capillary surface area, the permeability coefficient to CO across the foetal circulation was found to be approximately 4 x 10(-5)cm/s. This result is compatible with the hypothesis that the foetal circulation of the human placenta imposes a potentially significant barrier to gas transfer.

Prevalence of anal incontinence and other anorectal symptoms in women

We studied the prevalence of anal incontinence and other anorectal symptoms in women and evaluated the proportion of those who had sought medical help. A structured questionnaire was distributed to 1228 women attending the obstetrics and gynecology outpatient clinics (general, antenatal, urogynecology) of our university hospital. We also screened an additional sample of 984 women, representative of the general population aged 35-74. The prevalence of anal incontinence was 5.6% in the general outpatient clinic, 6.7% in the antenatal clinic, 15.9% in the urogynecology clinic and 4.4% in the general population. Only 20% of women affected by anal incontinence from the general outpatient clinic had reported their symptoms to a medical practitioner. Anal incontinence affects many women, but only a minority seek help. Obstetriciangynecologists should systematically inquire about the presence of this symptom.

Does a second delivery increase the risk of anal incontinence?

OBJECTIVE

To evaluate the prevalence of anal incontinence and anal sphincter defects after a first vaginal delivery and assess the effect of a second delivery.

DESIGN

Prospective cohort study using postal questionnaires assessing incontinence to flatus and stools at three and thirty months postnatally and anal endosonography at three months following delivery.

SETTING

Recruitment was from the antenatal clinic at the University Hospitals of Geneva, Switzerland.

POPULATION

One hundred women with a vaginal delivery of their first child.

MAIN OUTCOME MEASURES

Prevalence of anal incontinence and anal sphincter defects.

RESULTS

Anal incontinence was reported by 16/92 (17%) of women at three months after delivery and by 11/77 (14%) at 30 months. At that time, 5/54 (9%) with no further delivery reported incontinence, compared with 6/ 23 (26%) of those who had had another delivery (RR 2.8, 95% CI 1.0-8.3). Anal sphincter defects were diagnosed by endosonography in 46/87 (53%) women and were associated with reported incontinence at both three months (RR 1.9; 95% CI 1.4-2.6) and 30 months (RR 1.9: 95% CI 1.3-2.8) after delivery. The prevalence of anal incontinence at 30 months was highest (5/13, 39%) among those in whom a sphincter defect was diagnosed by endosonography after their first delivery and with a second delivery.

CONCLUSION

Anal incontinence after childbirth is associated with defects of the anal sphincter diagnosed by endosonography. Subsequent deliveries increase the risk of incontinence, particularly among women with a sphincter defect diagnosed after the first delivery.

Anal incontinence in women with third or fourth degree perineal tears and subsequent vaginal deliveries

We contacted 208 women 13 years after they suffered an obstetrical anal sphincter tear in order to estimate the effect of subsequent vaginal deliveries on anal continence. Among the 177 eligible responders, 129 sustained a partial or complete 3rd degree and 48 a 4th degree tear; 114 women had subsequent vaginal deliveries. Anal incontinence was more common in women with 4th (25.0%) than with 3rd degree tears (11.5%, p = 0.049). Subsequent vaginal deliveries were associated with a higher prevalence of severe incontinence in women with 4th degree tears (p = 0.023). No aggravation or increase in prevalence of incontinence was observed in women with 3rd degree tears. These results suggest that in a subsequent pregnancy, careful evaluation is necessary and an abdominal delivery may be advisable for women with previous major sphincter trauma.

Results of sphincter repair in postobstetric fecal incontinence

BACKGROUND

Postobstetric fecal incontinence is a rare and severe complications of vaginal delivery. Most often, it is the result of a tear of the anal sphincter, pudendal neuropathy, or a combination of the two.

STUDY DESIGN

Thirty-six patients operated upon at our institution for postobstetric fecal incontinence during a ten year period (1983 to 1992) were questioned (score) and examined to assess the operative results.

RESULTS

Preoperatively, all 36 patients (mean age of 37 years, range of 24 to 70 years) had sphincter tears and 32 patients were totally incontinent (score of 16 to 18). Three patients were moderately incontinent (score of 9) and one patient was incontinent of flatus only (score of 3). Eighty percent of the patients were referred with delay. Thirty-six sphincteroplasties with various degrees of rectovaginal and perianal reconstructions were performed. Twenty-eight women (78 percent) are continent (score of zero to 3), seven patients (19 percent) are partially incontinent (score of 4 to 6), and one patient (3 percent) is totally incontinent (score of 18). There was no mortality. Among the six postoperative complications, there were two sphincter breakdowns with persistent incontinence and four minor local complications.

CONCLUSIONS

Careful assessment and operative management of sphincter damage at the time of delivery as well as counseling of all women at risk for fecal incontinence are essential. Sphincteroplasty is a simple and safe procedure that offers symptomatic relief in almost all patients with sphincter lesions and cure in 80 percent.