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).     

Maternal body mass index and duration of labor

Objective

To evaluate whether the duration of the active phase of labor is associated with maternal body mass index (BMI), in nulliparous women with spontaneous onset of labor.

Study design

Historical prospective cohort study including 63,829 nulliparous women with a singleton pregnancy and a spontaneous onset of labor, who delivered between January 1, 1995 and December 31, 2009. Data were collected from the Perinatal Revision South registry, a regional perinatal database in Southern Sweden. Women were categorized into six classes of BMI. Overweight and obese women were compared to normal weight women regarding duration of active labor. Adjustments were made for year of delivery, maternal age and infant birth weight.

Results

The median duration of labor was significantly longer in obese women (class I obesity (BMI 30–34.9) = 9.1 h, class II obesity (BMI 35–39.9) = 9.2 h and class III obesity (BMI > 40) = 9.8 h) compared to normal-weight women (BMI 18.5–24.9) = 8.8 h (p < 0.001). The risk of labor lasting more than 12 h increased with increasing maternal BMI: OR 1.04 (1.01–1.06) (OR per 5-units BMI-increase).The risk of labor lasting more than 12 h or emergency cesarean section within 12 h, compared to vaginal deliveries within 12 h, increased with increasing maternal BMI. Duration of the second stage of labor was significantly shorter in obese women: in class III obesity the median value was 0.45 h compared to normal weight women, 0.55 h (p < 0.001).

Conclusion

In nulliparous women with a spontaneous onset of labor, duration of the active phase of labor increased significantly with increasing maternal BMI. Once obese women reach the second stage they deliver more quickly than normal weight women, which implies that the risk of prolonged labor is restricted to the first stage of labor. It is clinically important to consider the prolonged first stage of labor in obese women, for example when diagnosing first stage labor arrest, in order to optimize management of this rapidly growing at-risk group of women. Thus, it might be reasonable to adapt the considered upper limit for duration of labor, according to maternal BMI.     

The effect of relcovaptan (SR 49059), an orally active vasopressin V1a receptor antagonist,on uterine contractions in preterm labor

Relcovaptan (SR 49059) is a non-peptide, orally active vasopressin V_1a receptor inhibitor. The effect on uterine contractions in 18 women with preterm labor in pregnancy weeks 32–36 was assessed in a double-blind investigation. The inclusion criterion was at least four regular uterine contractions over 30?min as measured by external tocodynamometry. Twelve patients received at random a single oral dose of 400?mg relcovaptan and six received placebo, and contractions were monitored up to 6?h thereafter. Rescue medication (β-adrenoceptor-stimulating drug) was allowed after 2?h. Before drug administration a mean (?± SE) of 8.2?±?1.4 and 9.7?±?1.6 contractions/30?min were recorded in the relcovaptan- and placebo-treated groups, respectively. In the former group, the frequency of uterine contractions started to decrease within the first half hour, and 1.5–2?h after dosing it was steady at 3.2?±?0.9 contractions/30?min. Correspondingly, after placebo, 7.8?±?2.2 contractions/30?min were recorded, a statistically significant difference (p?=?0.017). The activity in the relcovaptan-treated women remained low, whereas in the placebo group inhibited uterine contractions were observed only in women receiving ‘rescue’ tocolytic treatment. It is concluded that relcovaptan inhibits preterm labor.     

Obstetrical outcome in women with self-prepared birth plan

Objective: To determine whether introducing a pre-prepared birth plan upon labor admission has an impact on obstetrical outcome.Methods: A retrospective study of all women who prepared an ante-partum birth plan, from 2007–2010. Outcome was compared with a control group consisting of women without a birth plan matched by age, parity and gestational week in a 3:1 ratio. Results: 154 women were compared to a matched control group of 462 women. Women preparing a birth plan, were less likely to undergo an intra partum cesarean section (11.7% vs. 20.3%, p = 0.016). First and second degree perineal tears occurred more frequently in women preparing a birth plan (72.1% vs. 25.5%, p < 0.001). The utilization of birth plan was also associated with a higher rate of epidural administration (81.2% vs. 68.8%, p = 0.004) and a lower rate of intravenous analgesics use (1.3% vs. 10.2%, p < 0.001). Conclusion:Women presenting with a birth plan, compared to an age-, parity- and gestational week- matched control group are less likely to undergo a cesarean section, more likely to have first and second degree perineal tears and more likely to use an epidural. The paucity of data and the mis-concepts of medical staff suggest that larger prospective studies are needed.     

Matched sample comparison of intramuscular versus vaginal micronized progesterone for prevention of preterm birth

Abstract

Objectives: To compare vaginal with intramuscular progesterone administration to prevent preterm labor in women with singleton pregnancies and at increased risk of preterm birth.

Study design: Prospective comparative clinical trial.

Population: One hundred and sixty pregnant women at 20–24 weeks gestation at the risk of preterm labor were classified into: 80 women who received micronized progesterone tablets 200?mg vaginally daily (Group A) and 80 women who received 100?mg progesterone in the form of intramuscular every third day (Group B).

Methods: Estimation of gestational age, assessment of fetal growth and fetal biophysical profile by trans-abdominal ultrasonographic examination was done every 4 weeks till delivery. Measurement of cervical length was achieved by transvaginal ultrasonography, done every 4 weeks till delivery.

Main outcome measures: Incidence of preterm delivery, mean gestational age and the incidence of adverse events of intramuscular versus vaginal route of progesterone administration.

Results: The incidence of preterm delivery in Group A was 20% and in Group B was 27.5%. The difference between both groups was statistically insignificant. In addition, the rate of adverse events reported in women received injectable progesterone was significantly higher than the rate of adverse events reported in women who received vaginal progesterone therapy.

Conclusion: Vaginally administrated progesterone was nearly as equally effective as intramuscular progesterone in the prevention of preterm labor in women at risk and in the meantime has less undesirable events.     

Interleukin-33 in the human placenta

Objective: Interleukin-33 (IL-33) is the newest member of the IL-1 cytokine family, a group of key regulators of inflammation. The purpose of this study was to determine whether IL-33 is expressed in the human placenta and to investigate its expression in the context of acute and chronic chorioamnionitis. Methods: Placental tissues were obtained from five groups of patients: 1) normal pregnancy at term without labor (n = 10); 2) normal pregnancy at term in labor (n = 10); 3) preterm labor without inflammation (n = 10); 4) preterm labor with acute chorioamnionitis and funisitis (n = 10); and 5) preterm labor with chronic chorioamnionitis (n = 10). Immunostaining was performed to determine IL-33 protein expression patterns in the placental disk, chorioamniotic membranes, and umbilical cord. mRNA expression of IL-33 and its receptor IL1RL1 (ST2) was measured in primary amnion epithelial and mesenchymal cells (AECs and AMCs, n = 4) and human umbilical vein endothelial cells (HUVECs, n = 4) treated with IL-1β (1 and 10?ng/ml) and CXCL10 (0.5 and 1 or 5?ng/ml). Results: 1) Nuclear IL-33 expression was found in endothelial and smooth muscle cells in the placenta, chorioamniotic membranes, and umbilical cord; 2) IL-33 was detected in the nucleus of CD14+ macrophages in the chorioamniotic membranes, chorionic plate, and umbilical cord, and in the cytoplasm of myofibroblasts in the Wharton’s jelly; 3) acute (but not chronic) chorioamnionitis was associated with the presence of IL-33+ macrophages in the chorioamniotic membranes and umbilical cord; 4) expression of IL-33 or IL1RL1 (ST2) mRNA in AECs was undetectable; 5) IL-33 mRNA expression increased in AMCs and HUVECs after IL-1β treatment but did not change with CXCL10 treatment; and 6) IL1RL1 (ST2) expression decreased in AMCs and increased in HUVECs after IL-1β but not CXCL10 treatment. Conclusions: IL-33 is expressed in the nucleus of placental endothelial cells, CD14+ macrophages, and myofibroblasts in the Wharton’s jelly. IL-1β can induce the expression of IL-33 and its receptor. Protein expression of IL-33 is detectable in macrophages of the chorioamniotic membranes in acute (but not chronic) chorioamnionitis.     

Waiting for postterm in healthy women,is it an accident waiting to happen?

Abstract

Objective: To establish whether postterm pregnancies are associated with adverse perinatal outcomes in a linear fashion.

Study design: A retrospective cohort study investigating perinatal outcomes in singleton term (≥37 weeks gestation) and postterm pregnancies was conducted. Deliveries occurred between the years 1988 and 2010. Parturients were classified into three groups according to their gestational age: 37–39?+?6, 40–41?+?6 and over 42 weeks’ gestation (postterm). Statistical analysis included multiple logistic regression model to control for possible confounders.

Results: Out of 202?462 deliveries, meeting the inclusion criteria, during the study period, 47.7% occurred at 37–39?+?6 weeks, 47.4% occurred at 40–41?+?6 weeks and 4.9% were postterm. Fertility treatments, diabetes mellitus, hypertensive disorders, intrauterine growth restriction (IUGR) and premature rupture of membranes (PROM) were less likely to be associated with postterm pregnancies. However, postterm was found as a significant risk factor for labor complications and adverse perinatal outcome including perinatal mortality. Using a multivariable logistic regression model, controlling for confounders such as maternal age and macrosomia, postterm was found to be an independent risk factor for perinatal mortality (adjusted OR?=?1.5; 95% CI?=?1.20–2.0; p?<?0.001).

Conclusion: Although postterm pregnancies were less likely to be associated with obstetrical risk factors and complications such as fertility treatments, diabetes mellitus, hypertensive disorders, IUGR and PROM, postterm is an independent risk factor for perinatal mortality.     

Comparative study of the outcome of induction of labor using 25 µg and 50 µg of vaginal misoprostol

Objective: To compare the safety and effectiveness of vaginal misoprostol 25 μg with those of 50 μg in induction of labor. Method: One hundred and sixty eligible women of low parity with indications for induction of labor at term were enrolled for the study. The subjects were randomized into two groups of vaginal misoprostol 25 µg and 50 µg dose regimens. Maternal characteristics, labor and newborn outcome were compared. Results: The total duration of labor was significantly shorter in the 50 µg group (8.24?±?1.5?h) than 25 µg group (9.09?±?2.7?h), p = 0.02. Oxytocin augmentation was significantly higher in the 25 µg group (18.75%) than in the 50 µg group (7.5%), p = 0.04. The indications for caesarean section were significantly different, (p = 0.02) between the two groups although the incidence was similar. The intrapartum adverse effects like fetal distress, meconium stained liquor, and tachysystole were significantly higher in the 50 µg group, p = 0.003. Similarly, the postpartum adverse effects such as cervical and vaginal tears were significantly higher in 50 µg group, p = 0.01. Conclusion: The two dose regimens were both effective in induction of labor, but 50 µg dose regimen resulted in significantly shorter duration of labor but with higher rate of labor complications than the 25 µg dose regimen.     

Scavenger receptor for hemoglobin in preterm prelabor rupture of membranes pregnancies complicated by histological chorioamnionitis

Objective: We sought to evaluate the distribution of scavenger receptor for hemoglobin positive (CD163⁺) cells in the placenta and fetal membranes from pregnancies complicated by preterm prelabor rupture of membranes with respect to the presence and absence of histological chorioamnionitis. Methods: Sixty-two women with singleton pregnancies with a gestational age between 24+0 and 36+6 weeks were included in a prospective cohort study. CD163 was evaluated by immunohistochemistry in the placenta and fetal membranes. The number of CD163⁺ cells and neutrophils was counted in the following locations: fetal membranes’ amnion, chorion, and decidua, as well as the placenta’s amnion, chorionic plate, subchorionic fibrin, stem villi, terminal villi, and decidua. Results: CD163⁺ cells were found in all compartments of the placenta and the fetal membranes regardless of the inflammatory status. A positive correlation between the number of CD163⁺ cells and neutrophils in the subchorionic fibrin and the chorionic plate was found. The number of CD163⁺ cells was higher in the placental subchorionic fibrin and chorionic plate when histological chorioamnionitis was present. Conclusion: The presence of histological chorioamnionitis affected the number of CD163⁺ cells in the placental chorionic plate and in the subchorionic fibrin but not in the fetal membranes.     

The effect of inflatable obstetric belts in nulliparous pregnant women receiving patient-controlled epidural analgesia during the second stage of labor

Abstract

Objective: The aim of this study was to evaluate the effect of inflatable obstetric belts on uterine fundal pressure in the management of the second stage of labor.

Method: Between July 2009 and December 2010, 188 nulliparous women with a singleton pregnancy at term were enrolled and only one dropped. The participants were randomized to receive either standard care (control group, n?=?91) or uterine fundal pressure by the Labor Assister? (Baidy M-520/Curexo, Inc., Seoul, Korea; active group, n?=?97) during the second stage of labor in addition to standard care. The Labor Assister is an inflatable obstetric belt that is synchronized to apply constant fundal pressure during a uterine contraction. The primary endpoint was duration of the second stage of labor in women who delivered vaginally (control, n?=?80 versus active, n?=?93). It was not analyzed in women who delivered by cesarean section (n?=?14) and delivered precipitously (n?=?1). The secondary outcomes are perinatal outcomes and perineal laceration. Participants received patient-controlled epidural analgesia.

Results: The 93 women in the active group spent less time in the second stage of labor when compared to the 80 women in the control group (46.51?±?28.01?min versus 75.02?±?37.48?min, p?<?0.001). There was no significant difference in perinatal outcomes and perineal laceration between the two groups.

Conclusion: The uterine fundal pressure exerted by the inflatable obstetric belt reduces the duration of the second stage of labor without complications in nulliparous women who receive patient-controlled epidural analgesia.