Twin pregnancies: guidelines for clinical practice from the French College of Gynaecologists and Obstetricians (CNGOF).

The rate of twin deliveries in 2008 was 15.6 per 1000 in France, an increase of approximately 80% since the beginning of the 1970s. It is recommended that chorionicity be diagnosed as early as possible in twin pregnancies (Professional Consensus). The most relevant signs (close to 100%) are the number of gestational sacs between 7 and 10 weeks and the presence of a lambda sign between 11 and 14 weeks (Professional Consensus). In twin pregnancies, nuchal translucency is the best parameter for evaluating the risk of aneuploidy (Level B). The routine use of serum markers during the first or the second trimester is not recommended (Professional Consensus). In the case of a choice about sampling methods, chorionic villus sampling is recommended over amniocentesis (Professional Consensus). Monthly follow-up by a gynaecologist-obstetrician in an appropriate facility is recommended for dichorionic pregnancies (Professional Consensus). A monthly ultrasound examination including an estimation of fetal weight and umbilical artery Doppler is recommended (Professional Consensus). It is recommended to plan delivery of uncomplicated dichorionic diamniotic twin pregnancies from 38 weeks and before 40 weeks (Level C). Monthly prenatal consultations and twice-monthly ultrasound are recommended for monochorionic twins (Professional Consensus). It is reasonable to consider delivery from 36 weeks but before 38 weeks+6 days, with intensified monitoring during that time (Professional Consensus). Prenatal care of monochorionic pregnancies must be provided by a physician working in close collaboration with a facility experienced in the management of this type of pregnancy and its complications (Professional Consensus). The increased risk of maternal complications and the high rate of medical interventions justify the immediate and permanent availability of a gynaecologist-obstetrician with experience in the vaginal delivery of twins (Professional Consensus). It is recommended that the maternity ward where delivery takes place have rapid access to blood products (Professional Consensus). Only obstetric history (history of preterm delivery) (Level C) and transvaginal ultrasound measurement of cervical length (Level B) are predictive factors for preterm delivery. No study has shown that the identification by transvaginal sonography (TVS) of a group at risk of preterm delivery makes it possible to reduce the frequency of such deliveries in asymptomatic patients carrying twins (Professional Consensus). It is important to recognize signs of TTTS early to improve the management of these pregnancies (Professional Consensus). Treatment and counseling must be performed in a center that can offer fetoscopic laser coagulation of placental anastomoses (Professional Consensus). This laser treatment is the first-line treatment (Level B). In the absence of complications after laser treatment, planned delivery is recommended from 34 weeks and no later than 37 weeks (Professional Consensus). For delivery, it is desirable for women with a twin pregnancy to have epidural analgesia (Professional Consensus). The studies about the question of mode of delivery have methodological limitations and lack of power. Active management of the delivery of the second twin is recommended to reduce the interval between the births of the two twins (Level C). In the case of non-cephalic presentation, total breech extraction, preceded by internal version manoeuvres if the twin's position is transverse, is associated with the lowest cesarean rates for second twins (Level C). In the case of high and not yet engaged cephalic presentation and if the team is appropriately trained, version by internal manoeuvres followed by total breech extraction is to be preferred to a combination of resumption of pushing, oxytocin perfusion, and artificial rupture of the membranes, because the former strategy appears to be associated with fewer cesareans for the second twin (Level C).

Vayssière C ，Benoist G ，Blondel B ，Deruelle P ，Favre R ，Gallot D ，Jabert P ，Lemery D ，Picone O ，Pons JC ，Puech F ，Quarello E ，Salomon L ，Schmitz T ，Senat MV ，Sentilhes L ，Simon A ，Stirneman J ，Vendittelli F ，Winer N ，Ville Y ，French College of Gynaecologists and Obstetricians ... -  《-》

Delivery for women with a previous cesarean: guidelines for clinical practice from the French College of Gynecologists and Obstetricians (CNGOF).

The primary cause of uterine scars is a previous cesarean. In women with a previous cesarean, the risks of maternal complications are rare and similar after a trial of labor after cesarean (TOLAC) and after an elective repeat cesarean delivery (ERCD), but the risk of uterine rupture is higher with TOLAC (level of evidence [LE]2). Maternal morbidity in women with previous cesareans is higher when TOLAC fails than when it leads to successful vaginal delivery (LE2). Although maternal morbidity increases progressively with the number of ERCD, maternal morbidity of TOLAC decreases with the number of successful previous TOLAC (LE2). The risk-benefit ratio considering the risks of short- and long-term maternal complications is favorable to TOLAC in most cases (LE3). Globally, neonatal complications are rare regardless of the mode of delivery for women with previous cesareans. The risks of fetal, perinatal, and neonatal mortality during TOLAC are low. Nonetheless, these risks are significantly higher than those associated with ERCD (LE2). The risks of mask ventilation, intubation for meconium-stained amniotic fluid, and neonatal sepsis all increase in TOLAC (LE2). The risk of transient respiratory distress increases in ERCD (LE2). To reduce this risk, and except in particular situations, ERCD must not be performed before 39 weeks (grade B). TOLAC is possible for women with a previous cesarean before 37 weeks, with 2 previous cesareans, with a uterine malformation, a low vertical incision or an unknown incision, with a myomectomy, postpartum fever, an interval of less than 6 months between the last cesarean delivery and the conception of the following pregnancy, if the obstetric conditions are favorable (professional consensus). ERCD is recommended in women with a scar in the uterine body (grade B) and a history of 3 or more cesareans (professional consensus). Ultrasound assessment of the risk of uterine rupture in women with uterine scars has not been shown to have any clinical utility and is therefore not recommended during pregnancy to help decide the mode of delivery (professional consensus). Use of X-ray pelvimetry to decide about TOLAC is associated with an increase in the repeat cesarean rate without any reduction in the rate of uterine rupture (LE2). It is unnecessary for deciding mode of delivery and for managing labor during TOLAC (grade C). TOLAC should be encouraged for women with a previous vaginal delivery either before or after the cesarean, a favorable Bishop score or spontaneous labor, and for preterm births (grade C). For women with a fetus with an estimated weight of more than 4500 g, especially in the absence of a previous vaginal delivery and those with supermorbid obesity (BMI>50), ERCD must be planned from the outset (grade C). For all of the other clinical situations envisioned (maternal age>35 years, diabetes, morbid obesity, prolonged pregnancy, breech presentation and twin pregnancy), TOLAC is possible but the available data do not allow specific guidelines about the choice of mode of delivery, in view of the low levels of proof (grade C). The decision about planned mode of delivery must be shared by the patient and her physician and made by the 8th month, taking into account the individual risk factors for TOLAC failure and uterine rupture (professional consensus). TOLAC is the preferred choice for women who do not have several risk factors (professional consensus). The availability onsite of an obstetrician and anesthetist must be pointed out to the patient. If the woman continues to prefer a repeat cesarean after adequate information and time to think about it, her preference should be honored (professional consensus). Labor should be induced in woman with a previous cesarean only for medical indications (professional consensus). Induction of labor increases the risk of uterine rupture, which can be estimated at 1% if oxytocin is used and 2% with vaginal prostaglandins (LE2). Mechanical methods of induction have not been studied sufficiently. Misoprostol appears to increase the risk of uterine rupture strongly (LE4). Based on the information now available, its use is not recommended (professional consensus). Routine use of internal tocodynamometry does not prevent uterine rupture (professional consensus). The increased risk of uterine rupture associated with oxytocin use is dose-dependent (LE3). In the active phase, it is recommended that the total duration of failure to progress should not exceed 3h; at that point, a cesarean should be performed (professional consensus). Epidural analgesia must be encouraged. The simple existence of a uterine scar is not an indication for a routine manual uterine examination after VBAC (grade C).

Sentilhes L ，Vayssière C ，Beucher G ，Deneux-Tharaux C ，Deruelle P ，Diemunsch P ，Gallot D ，Haumonté JB ，Heimann S ，Kayem G ，Lopez E ，Parant O ，Schmitz T ，Sellier Y ，Rozenberg P ，d'Ercole C ... -  《-》

Instrumental delivery: clinical practice guidelines from the French College of Gynaecologists and Obstetricians.

Routine use of a partograph is associated with a reduction in the use of forceps, but is not associated with a reduction in the use of vacuum extraction (Level A). Early artificial rupture of the membranes, associated with oxytocin perfusion, does not reduce the number of operative vaginal deliveries (Level A), but does increase the rate of fetal heart rate abnormalities (Level B). Early correction of lack of progress in dilatation by oxytocin perfusion can reduce the number of operative vaginal deliveries (Level B). The use of low-concentration epidural infusions of bupivacaine potentiated by morphinomimetics reduces the number of operative interventions compared with larger doses (Level A). Placement of an epidural before 3-cm dilatation does not increase the number of operative vaginal deliveries (Level A). Posterior positions of the fetus result in more operative vaginal deliveries (Level B). Manual rotation of the fetus from a posterior position to an anterior position may reduce the number of operative deliveries (Level C). Walking during labour is not associated with a reduction in the number of operative vaginal deliveries (Level A). Continuous support of the parturient by a midwife or partner/family member during labour reduces the number of operative vaginal deliveries (Level A). Under epidural analgesia, delayed pushing (2h after full dilatation) reduces the number of difficult operative vaginal deliveries (Level A). Ultrasound is recommended if there is any clinical doubt about the presentation of the fetus (Level B). The available scientific data are insufficient to contra-indicate attempted midoperative delivery (professional consensus). The duration of the operative intervention is slightly shorter with forceps than with a vacuum extractor (Level C). Nonetheless, the urgency of operative delivery is not a reason to choose one instrument over another (professional consensus). The cup-shaped vacuum extractor seems to be the instrument of choice for operative deliveries of fetuses in a cephalic transverse position, and may also be preferred for fetuses in a posterior position (professional consensus). Vacuum extraction deliveries fail more often than forceps deliveries (Level B). Overall, immediate maternal complications are more common for forceps deliveries than vacuum extraction deliveries (Level B). Compared with forceps, operative vaginal delivery using a vacuum extractor appears to reduce the number of episiotomies (Level B), first- and second-degree perineal lesions, and damage to the anal sphincter (Level B). Among the long-term complications, the rate of urinary incontinence is similar following forceps, vacuum extraction and spontaneous vaginal deliveries (Level B). Anal incontinence is more common following forceps delivery (Level B). Persistent anal incontinence has a similar prevalence regardless of the mode of delivery (caesarean or vaginal, instrumental or non-instrumental), suggesting the involvement of other factors (Level B). Rates of immediate neonatal mortality and morbidity are similar for forceps and vacuum extraction deliveries (Level B). It appears that difficult instrumental delivery may lead to psychological sequelae that may result in a decision not to have more children (Level C). The rates of neonatal convulsions, intracranial haemorrhage and jaundice do not differ between forceps and vacuum extraction deliveries (Levels B and C). Rapid sequence induction with a Sellick manoeuvre (pressure to the cricoid cartilage) and tracheal intubation with a balloon catheter is recommended for any general anaesthesia (Level B). Training must ensure that obstetricians can identify indications and contra-indications, choose the appropriate instrument, use the instruments correctly, and know the principles of quality control applied to operative vaginal delivery. Nowadays, traditional training can be accompanied by simulations. Training should be individualized and extended for some students.

Vayssière C ，Beucher G ，Dupuis O ，Feraud O ，Simon-Toulza C ，Sentilhes L ，Meunier E ，Parant O ，Schmitz T ，Riethmuller D ，Baud O ，Galley-Raulin F ，Diemunsch P ，Pierre F ，Schaal JP ，Fournié A ，Oury JF ，French College of Gynaecologists and Obstetricians ... -  《-》

Prenatal screening for and diagnosis of aneuploidy in twin pregnancies.

Audibert F ，Gagnon A ，Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada ，Prenatal Diagnosis Committee of the Canadian College of Medical Geneticists ... -  《-》

Prolonged and post-term pregnancies: guidelines for clinical practice from the French College of Gynecologists and Obstetricians (CNGOF).

The duration of pregnancy varies between 40(+0) and 41(+3) weeks. Conventionally, and essentially arbitrarily, a pregnancy is considered to be "prolonged" after 41(+0) weeks, but the infant is not considered "post-term" until 42(+0) weeks (Professional consensus). A term birth thus occurs during the period from 37(+0) to 41(+6) weeks. In France, prolonged pregnancies (≥41(+0)weeks) involve 15-20% of pregnant women, and post-term pregnancies (≥42(+0) weeks) approximately 1%. The frequency of post-term pregnancies is very heterogeneous: in Europe and the United States, it ranges from 0.5% to 10% according to country. In prolonged pregnancies, the cesarean section rate-especially the emergency cesarean rate-is multiplied by approximately 1.5 (grade B). From 37(0-6) to 43(0-6) weeks, the risk of perinatal mortality increases regularly, from 0.7‰ to 5.8‰. Meconium aspiration syndrome is responsible for substantial morbidity and mortality, and its incidence increases regularly between 38(+0) and 42(+6) weeks, from 0.24‰ to 1.42‰ (grade B). Similarly, the risks of neonatal acidosis (grade B), 5-min Apgar scores less than 7 (grade B) and admissions to neonatal intensive care (grade B) increase progressively between 38(+0) and 42(+6) weeks. These risks appear to double for post-term growth-restricted newborns (grade C). Ultrasound dating of the pregnancy makes it possible to reduce the risk that it will be incorrectly considered prolonged and that labor will therefore be induced unnecessarily. To harmonize practices, if the crown-rump length (CRL) is correctly measured (this measurement should be taken between 11(+0) and 13(+6) weeks, when CRL should measure from 45 to 84mm), ultrasound dating based on it should be used to determine the official date pregnancy began, regardless of its difference from the date assumed by the patient or estimated based on the date of the last menstrual period. This rule does not apply to pregnancies by IVF, for which the date pregnancy began is defined by the date of oocyte retrieval (Professional consensus). From 37(0-6) to 43(0-6) weeks, the risk of perinatal mortality increases regularly and there is no threshold at which a clear increase in perinatal mortality becomes visible. Fetal monitoring by cardiotocography (CTG) that begins at 41(+0) weeks would cover approximately 20% of women and reduce perinatal morbidity compared with monitoring that begins at 42(+0) weeks (grade C). The frequency recommended for this monitoring ranges between two and three times a week (Professional consensus). For ultrasonography assessment, measurement of the largest fluid pocket is recommended, because measurement of the amniotic fluid index (that is, the sum of the four quadrants) is accompanied by more diagnoses of oligohydramnios, inductions of labor, and cesareans for fetal distress without any improvement in neonatal prognosis (grade A). The practice of assessing the Manning biophysical score increases the number of diagnoses of oligohydramnios and fetal heart rage (FHR) abnormalities and generates an increase in the rates of inductions and cesareans without improving neonatal prognosis. The use of this biophysical score in monitoring prolonged pregnancies is therefore not recommended (grade B). In the absence of a specific disorder, induction of labor can be proposed in patients between 41(+0) and 42(+6) weeks (grade B). Nonetheless, the choice of prolongation beyond above 42(+0) weeks appears to involve an increase in fetal risk, which must be explained to the patient and balanced against the potential disadvantages of induction (Professional consensus). Stripping the membranes can reduce the duration of pregnancy by increasing the number of patients going into labor spontaneously during the week afterward (grade B). Compared to an expectant approach, it does not increase the cesarean section rate (grade A). It reduces recourse to induction by 41% at 41(+0) weeks and by 72% at 42(+0) weeks (grade B), without increasing the risk of either membrane rupture or maternal or neonatal infection (grade B). Used as a tampon or vaginal gel, prostaglandins E2 (PGE2) are an effective method of inducing labor (grade A). They can be used to induce labor successfully, regardless of cervical ripeness (grade A). If misoprostol is chosen, the lowest dose is to be preferred, starting with a vaginal dose of 25μg every 3-6h (grade A). For misoprostol, more powerful studies remain necessary for better defining the doses, routes of administration, tolerance and indications. Misoprostol at any dose is contraindicated in women with uterine scars (grade B). Placement of an intracervical Foley catheter is an effective mechanical means of inducing labor, with less uterine hyperstimulation than prostaglandins and no increase in the cesarean section rate (grade A). Nonetheless, as the risk of infection might be increased, this technique requires more robust evaluation before entering general practice (grade B). In cases of meconium-stained amniotic fluid, pharyngeal aspiration before delivery of the shoulders is not recommended (grade A). The team managing a post-term newborn with meconium-stained amniotic fluid at birth must know how to perform intubation and, if the intubation is not helpful, endotracheal aspiration (grade C) and ventilation with a mask. Routine endotracheal intubation of a vigorous newborn is not recommended (grade A).

Vayssière C ，Haumonte JB ，Chantry A ，Coatleven F ，Debord MP ，Gomez C ，Le Ray C ，Lopez E ，Salomon LJ ，Senat MV ，Sentilhes L ，Serry A ，Winer N ，Grandjean H ，Verspyck E ，Subtil D ，French College of Gynecologists and Obstetricians (CNGOF) ... -  《-》