Influence d’une forte diminution du recours à l’épisiotomie appliquée à une situation à haut risque périnéal : le dégagement en occipito-sacré

Risk factors for obstetric anal sphincter injuries (OASIS) and the role of episiotomy: A retrospective series of 496 cases

OBJECTIVE

The objective of this study was to determine the prevalence and identify risk factors for obstetric anal sphincter injuries (OASIS), and to determine the prevalence of episiotomy and whether it is protective for the posterior perineum.

STUDY DESIGN

This is a retrospective case-control study carried out in a level 2 maternity unit and a level 3 maternity unit between 1 January 2006 and 31 December 2015. The sample population included all vaginal deliveries at term of a living singleton foetus in cephalic presentation. The case group comprised patients with an OASIS. The control group comprised patients without OASIS. Statistical analysis was subdivided into descriptive and inferential parts.

RESULTS

42,626 patients were included in the study of whom 496 were cases of OASIS, i.e. a rate of 1.2%. The overall episiotomy rate was 10.0%, which reflects a restrictive practice. Episiotomy doesn't appear to be a statistically significant protective factor for OASIS (OR=0.89-95%CI [0.68-1.16]). The principal independent risk factors for OASIS were nulliparity (ORa=4.19-95%CI [3.03-5.84] - p<0.001), previous caesarean (ORa=5.59-95%CI [3.68-8.44] - p<0.001), uterine fundal height greater than 32cm (ORa=1.35-95%CI [1.03-1.77] - p=0.03), gestational or pre-pregnancy diabetes (ORa=1.76-95%CI [1.22-2.46] - p=0.002), birthweight of more than 3500g (ORa=1.48-95%CI [1.17-1.87] - p=0.001), assisted delivery (ORa=1.81-95%CI [1.18-2.86] - p=0.007), and use of a second instrument or obstetrical manoeuvre (ORa=1.93-95%CI [1.05-3.30] - p=0.02).

CONCLUSION

Episiotomy doesn't appear to be a statistically significant protective factor on the perineal prognosis. A deeper understanding of the factors which promote OASIS and greater awareness of them would improve the perineal prognosis of parturient women.

[Fetal expulsion: Which interventions for perineal prevention? CNGOF Perineal Prevention and Protection in Obstetrics Guidelines]

OBJECTIVE

The objective for all obstetricians and midwifes who intervene during the release of the fetal presentation is to prevent at best the perineal lesions. This work consisted in analyzing the literature, researching and evaluating interventions that reduce this perineal risk during the release.

METHODS

A keyword search for each medical intervention during the expulsion phase was conducted by selecting studies assessing perineal risk. Interventions during pregnancy and during delivery before the expulsion phase were specifically addressed in other sections of the recommendations.

RESULTS

Firstly, the degree of perineal stretching during the second stage of labour does not appear to be a risk factor for OASIS, postpartum incontinence, or sexual disorders (LE3) and that a substantial stretching of the perineum is not an indication of episiotomy (Professional consensus). Then, manual control of the expulsion of the fetus at the end of the second stage of labour and support of the posterior perineum during this time appear to reduce the rate of OASIS (LE3). The crowning of the baby's head should be manually controlled and the posterior perineum manually supported manually to reduce the risk of OASIS (GradeC). There is no recognised benefit to episiotomy in normal deliveries (LE1); the liberal practice of episiotomy results in fewer intact perineums than its restrictive practice, and the latter does not result in increasing the number of cases of OASIS. No evidence indicates that an episiotomy for women with a breech presentation, twin pregnancy, or posterior position prevents OASIS (LE3). Indication for episiotomy during delivery depends on individual risk factors and obstetric conditions (Professional consensus). It is recommended that the indication for episiotomy be explained and the woman's consent received before its performance. The performance of an episiotomy during normal deliveries is not recommended to reduce the risk of OASIS (Grade A). The liberal practice of episiotomy to prevent OASIS is not recommended for women with a breech presentation, twin pregnancy, or posterior position (GradeC). Episiotomy during an instrumental delivery appears to be associated with a reduction of the risk of OASIS (LE3). The vacuum extractor appears to induce fewer cases of OASIS than other instruments (LE3). Episiotomy may be indicated in instrumental deliveries to avoid OASIS (GradeC). Training in perineal protection in obstetrics is recommended (Grade B). In operative vaginal deliveries when several instruments can be used, a vacuum extractor is preferentially recommended to reduce the risk of OASIS (GradeC). When forceps or spatulas are used, it is preferable that they be withdrawn just before cephalic deflexion so that the fetal head is not "capped" with these instruments at birth (Professional consensus). Couder's maneuver, which consists of lowering the forearm during the release of the fetal shoulders, appears to decrease the rate of second-degree perineal tears and increase the rate of intact perineum (LE3).

CONCLUSION

Manual control of the expulsion and perineal support reduce the risk of perineal injury. There is no benefit to episiotomy in normal delivery, nor in special cases such the breech presentation for example. On the other hand, in case of instrumental delivery, an episiotomy may be indicated to avoid OASIS (GradeC), and it is recommended if it is possible to use the ventouse preferentially. The Couder's maneuver seems to reduce the rate of 2^nd degree perineal lesions (LE3). Finally, training in perineal obstetric protection is recommended (Grade B).

[Can the rate of episiotomy still be lowered? Status update in PACA region (south of France)]

OBJECTIVE

To evaluate professional practices relative to episiotomies in the Provence Alpes Côte d'Azur (PACA) region by analysing their incidence in maternity hospitals, by type and by sector of activity. Following this, to analyse maternal and obstetric characteristics associated with episiotomies and the occurrence of perineal tears in Marseille's university hospitals (CHU).

METHODS

Data were extracted from the database for the period from 1st January 2012 to 31 December 2014. The sample included 41 maternity hospitals: 13 private and 28 public. Twenty of the maternity hospitals were level 1, 15 were level 2, and 2 were level 3 (Nice and AP-HM).

RESULTS

In the PACA region, 176,573 patients gave birth by vaginal delivery. The incidence of episiotomy over the 3 years was 21.6% (0.50% - 76.13%) with a statistically significant reduction in the incidence between 2012 and 2014 (P<0.001). There was a significant difference by sector (P<0.001) and level (P<0.001) of maternity hospitals. In the Marseille CHU, 21.6% of women had an episiotomy (66.4% in primiparas - 33.6% in multiparous) and 43% had perineal tears (62.3% in primiparas - 37.7% in multiparous). After multivariate analysis, gender, weight of the newborn, presentation, gestational age, and mode of delivery were shown to be factors significantly associated with occurrence of episiotomy and occurrence of perineal tear (P<0.001).

CONCLUSION

A significant decrease in the incidence of episiotomy was observed in the PACA region from 2012 to 2014, associated with a wide variation in rates depending on the maternity hospitals, their types and their sectors.