Induction of labor in twin gestation: lessons from a population based study

Introduction: The route of delivery and the role of induction of labor in twin gestations are controversial. The aim of this study was to determine the efficacy of induction of labor in twin gestations.

Methods: This retrospective population based cohort study included 4605 twin gestations divided into following groups: 1) spontaneous parturition (n?=?2937, 63.78%); 2) induction of labor (n?=?653, 14.2%) and 3) elective cesarean delivery (n?=?1015, 22.04%).

Results: The rate of vaginal delivery in the labor induction group was 81% (529/653). In comparison to the other study groups, induction of labor in twins was independently associated with a 77% reduction in the risk of cesarean delivery (OR 0.23; 95% CI 0.18–0.31) and a 78% reduction in the risk of postpartum death for the second twin (OR 0.22; 95% CI 0.05–0.94). The rate of nulliparity, term delivery and labor dystocia was higher in the induction of labor group (p?<?0.001 in all comparisons).

Conclusions: Our results suggest that induction of labor in twin gestation is successful and is independently associated with substantial reduction in the risk of cesarean delivery and postpartum death of the second twin.     

The association between nitroglycerin use and adverse outcomes in women undergoing cesarean delivery in the second stage of labor

Objective: To identify predictors of hysterotomy extension in women undergoing cesarean delivery (CD) in the second stage of labor, and whether use of nitroglycerin (NTG) during CD has a protective effect.

Methods: We conducted a retrospective cohort study of women undergoing CD in the second stage of labor from 2012 to 2015. Some women received NTG at the obstetrician’s request. Logistic regression was used to examine the relationship between second stage duration and NTG administration on maternal and neonatal outcomes.

Results: Of the 391 women in the sample, 27% had an extension and 12% received NTG. Second stage?≥4?h was associated with a 2.14-fold higher risk of extension (95% CI 1.22–3.75), a 2.00-fold higher risk of hemorrhage (95% CI: 1.20–3.33) and 2.42-fold higher risk of blood transfusion during delivery hospitalization (95% CI: 0.99–5.91). Intravenous (IV) and sublingual-spray (SL-spray) NTG administration were not associated with an increased risk of hemorrhage or extension. SL-NTG was associated with 4.68-fold increased odds of 5-min Apgar?<7 (95% CI 1.42–15.41) and 3.36-fold greater odds of NICU admission (95% CI 1.20–9.41).

Conclusion: We found no evidence that NTG protects against extension, and SL-NTG use was associated with adverse neonatal outcomes. Clinical trials should be conducted to evaluate risk and benefits of NTG use.     

Is induction of labor risky for twins compare to singleton pregnancies?

Abstract

Objective: The aim of this study was to investigate whether induction of labor in twin pregnancies is associated with higher rates of maternal complications as compared to singletons.

Method: A retrospective population-based study was conducted to compare maternal complications following induction of labor in twin pregnancies and singletons at Soroka University Medical Center, Be'er-Sheva, Israel, between 1988 and 2010. Stratified analysis using a multiple logistic regression model was performed to control for confounders.

Results: The study population included 25?913 patients following induction of labor, of these 191 (0.73%) were in twin pregnancies. Induction of labor in twin pregnancies was not associated with adverse maternal outcomes such as cervical tears, third degree perineal tears, uterine rupture, peripartum hysterectomy, post-partum hemorrhage or retained placenta. However, labor induction in twins was significantly associated with cesarean deliveries (31.2% versus 17.1%; p?<?0.001).

Using a multivariable analysis controlling for confounders, induction at twins was an independent risk factor for cesarean delivery (CD; adjusted OR?=?2.2, 95% CI 1.7–2.7, p?<?0.001).

Conclusion: Induction of labor in twin pregnancies does not increase the risk for maternal complications. However, it is an independent risk factor for CD.     

Daily gentamicin using ideal body weight demonstrates lower risk of postpartum endometritis and increased chance of successful outcome compared with traditional 8-hour dosing for the treatment of intrapartum chorioamnionitis

Background: Clinical chorioamnionitis complicates approximately 1–4% of pregnancies overall. Although universal agreement does not exist regarding the antibiotic regimen of choice, most studies have evaluated intravenous ampicillin dosed at 2?g every 6 hours plus gentamicin dosed every 8 hours. Only three studies have examined daily gentamicin for the treatment of intrapartum chorioamnionitis and thus is insufficiently investigated.

Objective: This study seeks to determine whether daily dosing of gentamicin using ideal body weight for the treatment of intrapartum chorioamnionitis is more or equivalently efficacious when compared to traditional 8-hour dosing regimens.

Materials and methods: We conducted a retrospective cohort study and reviewed charts on all women receiving treatment for intrapartum chorioamnionitis, which included intravenous gentamicin daily dosing calculated using 5?mg/kg ideal body weight or receiving traditional every 8 hours dosing of gentamicin at two large academic centers. Our primary outcomes were resolution of infection following delivery without the development of maternal endometritis and/or neonatal sepsis. Baseline characteristics were compared between dosing groups using Welch two-sample t-tests for continuous variables, uncorrected X² test and exact binomial 95% confidence intervals. We calculated the risk ratios of each outcome in the ideal versus traditional dosing groups using modified Poisson regression, both crude and adjusted. Adjusted models were controlled for variables determined to be potential confounders, which included BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34?y), and parity.

Results: The study included 500 patients with 255 patients receiving daily dosing of gentamicin and 245 receiving traditional dosing of gentamicin. Of the patients receiving daily gentamicin compared to traditional dosing, 95.7% (95% CI 94.9–96.6%) achieved the primary outcome versus 92% (95% CI 90.8???93.2%), 2.4% (95% CI 1.8–3%) developed endometritis versus 5.6% (4.5–6.7%), 1.6% (95% CI 1.1–2.1%) delivered neonates with sepsis versus 3.3% (CI 2.5–4.1%), and 36.9% required cesarean delivery versus 41.4%. In crude analysis, compared to traditional dosing, IDW daily dosing was associated with a lower risk of postpartum endometritis (RR 0.42, 95% CI 0.16–1.10, p?=?.032). After adjusting for BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34?y), and parity, the IDW daily dosing group had a 5% greater chance of successful outcome (RR 1.05, 95% CI 1.00–1.10, p?=?.046) and a 64% lower risk of endometritis (RR 0.35, 95% CI 0.15–0.83, p?=?.017).

Conclusion: Daily dosing of gentamicin using ideal body weight is associated with a lower risk of postpartum endometritis and high chance of a successful outcome in the treatment of intrapartum chorioamnionitis compared with traditional 8-hour dosing in our ethnically diverse, urban population and thus may be considered a superior option to every 8 hours dosing regimens.     

Is low-dose aspirin therapy to prevent preeclampsia more efficacious in non-obese women or when initiated early in pregnancy?

Objective: Late timing of intervention and maternal obesity are potential explanations for the modest effect of aspirin for preeclampsia prevention. We explored whether low-dose aspirin (LDA) is more effective in women at increased risk when initiated before 16 weeks' gestation or given to non-obese women.

Methods: Secondary analysis of a trial to evaluate LDA (60?mg/d) for preeclampsia prevention in high-risk women. Participants were randomized to LDA or placebo between 13 and 26 weeks. We stratified the effect of LDA on preeclampsia by (a) timing of randomization (Results: Of 2503 women, 461 (18.4%) initiated LDA?p value for interaction?=?0.87). Similarly, LDA effect was not better in non-obese (RR: 0.91, 95% CI: 0.7–1.13) versus obese women (RR: 0.89, 95% CI: 0.7–1.13), (p value for interaction?=?0.85).

Conclusion: LDA for preeclampsia prevention was not more effective when initiated 相似文献   

Method of delivery and intraventricular haemorrhage in extremely preterm infants

Objectives.?It has been reported that caesarean delivery (CD) protects against intraventricular haemorrhage (IVH) in the extremely preterm infant, but it is not known whether this effect involve the more severe grades of IVH. Thus, our aim was to confirm the correlation between the occurrence of IVH and the mode of delivery, and to evaluate this correlation for each grade of IVH.

Methods.?All infants with gestational age (GA)?≤?28 weeks admitted to the neonatal intensive care unit of a tertiary hospital were studied for each grade IVH and major complications rate.

Results.?We found that vaginally born infants had a higher rate of each grade of IVH, but the increase was statistically significant only for grade 3 IVH (18% vs. 2%, p?<?0.0001) and all grades IVH (45% vs. 20%, p?<?0.0001). Multivariate analysis demonstrated that CD (RR: 0.42, 95% CI 0.28–0.63), birth weight?≥?800?g (RR: 0.48, 95% CI 0.32–0.73), 27–28 weeks of GA (RR: 0.38, 95% CI 0.25–0.60) and antenatal steroids (0.66, 95% CI 0.22–0.46) decrease independently the risk of developing IVH.

Conclusions.?Our study demonstrates that CD decreases the risk of developing IVH in extremely preterm infants including the most severe grades of IVH.     

Is the risk of obstetric anal sphincter injuries increased in vaginal twin deliveries?

Objective: Vaginal twin deliveries have a higher rate of intrapartum interventions. We aimed to determine whether these characteristics are associated with an increased rate of obstetric anal sphincter injuries compared with singleton.

Study design: Retrospective study of all twin pregnancies undergoing vaginal delivery trial was conducted from January 2000–September 2014. Sphincter injury rate compared with all concurrent singleton vaginal deliveries. Multivariable analysis was used to determine twin delivery association with sphincter injuries while adjusting for confounders.

Results: About 717 eligible twin deliveries. Outcome was compared with 33?886 singleton deliveries. Twin pregnancies characterized by a higher rate of nulliparity (54.8% versus 49.5%, p?=?0.005), labor induction (42.7% versus 29.1%, p?<?0.001), and instrumental deliveries (27.5% versus 16.7%, p?<?0.001), lower gestational (34.6?±?3.3 versus 38.8?±?2.3, p?<?0.001), and lower birth weight. Total breech extraction was performed in 29.0% (208/717) of twin deliveries. Overall obstetric sphincter injury rate was significantly lower in the twins group (2.8% versus 4.4%, p?=?0.03, OR?=?0.6, 95% CI 0.4–0.9), due to lower rate of 3rd degree tears in twins versus singletons (2.2% versus 4.0%, p?=?0.02), rate of 4th degree tears similar among the groups (0.6% versus 0.4%, p?=?0.5). In multivariable analysis, sphincter injuries were associated with nulliparity (OR?=?3.9, 95% CI 3.4–4.5), forceps (OR?=?6.8, 95% CI 5.8–7.8), vacuum (OR?=?2.9, 95% CI 2.5–3.3), earlier gestational age (OR?=?0.2, 95% CI 0.1–0.3), episiotomy (OR?=?0.8, 95% CI 0.7–0.9), and birth weight over 3500?g (OR?=?1.8, 95% CI 1.6–2.0). However, the association between twins (versus singletons) deliveries and sphincter injuries was lost after adjustment for delivery gestational age (OR?=?0.7, 95% CI 0.4–1.2).

Conclusion: Despite a higher rate of intrapartum interventions, the rate of sphincter injuries is lower in twins versus singleton deliveries, mainly due to a lower gestational age at delivery.     

Foley catheter with simultaneous oxytocin on labor induction: a meta-analysis of randomized controlled trials

Objective: It is unclear that whether Foley catheter with simultaneous oxytocin could improve the efficacy of induction outcome.

Method: To conduct a meta-analysis of randomized controlled trial (RCT) studies to evaluate the effect of Foley catheter with simultaneous oxytocin on labor induction. PubMed, Embase, and other databases were searched from their inception to July 2017. We included all RCTs comparing Foley catheter with simultaneous oxytocin (i.e. intervention group) with Foley catheter followed by oxytocin (i.e. control group) in the three kinds of women (nulliparas and multiparas/only nulliparas/only multiparas). We estimate summarized relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes, standard mean difference for continuous outcomes. Fixed- and random-effects models were used, depending on heterogeneity.

Results: After application of our inclusion and exclusion criteria, six RCTs with a total of 1133 participants were identified. We found that only nulliparas had significant RR of delivery within 24?h (RR?=?1.32, 95% CI: 1.12, 1.55, I²?=?46.5%). Meanwhile, there was no statistically significant difference between intervention and control groups in vaginal delivery in 24?h, cesarean delivery, time to delivery, and Apgar score at 5?min less than 7. Foley catheter with simultaneous oxytocin did not increase the risk of side effects, included chorioamnionitis, postpartum hemorrhage, uterine hyperstimulation, and neonatal intensive care unit admission.

Conclusion: The results seem to support the use of oxytocin to a Foley catheter at the initiation of labor induction, as it might lead to increases the rate of delivery within 24?h in nulliparas.     

Efficacy and safety of misoprostol compared with the dinoprostone for labor induction at term: a meta-analysis

Objective: The purpose of this study was to compare the efficacy and safety of intravaginal misoprostol and the dinoprostone vaginal insert for labor induction at term.

Method: PubMed, EMBASE, MEDLINE, CNKI, EBSCO and the Cochrane Library were searched for articles published in English language from 2000 to 2014, Using the keywords misoprostol, dinoprostone, labor induction.

Results: Eight of 436 studies (1669 women) identified met the criteria for meta-analysis. We assigned a quality rating to each included article. The use of misoprostol showed less oxytocin augmentation when compared with dinoprostone (RR?=?0.78, 95% CI?=?0.67–0.90). There was no difference in the risk of tachysystole (RR?=?1.18, 95% CI?=?0.78–1.79), uterine hyperstimulation (RR?=?1.24, 95% CI?=?0.75–2.06), vaginal delivery within 24?h (RR?=?1.10, 95% CI?=?1.00–1.20), cesarean delivery (RR?=?0.84, 95% CI?=?0.56–1.24), Neonatal Intensive Care Unit admission (RR?=?0.86, 95% CI?=?0.58–1.28), Apgar scores <7 in 5?min (RR?=?1.18, 95% CI?=?0.39–3.63) between misoprostol and dinoprostone.

Conclusion: Misoprostol compared with dinoprostone appears to show less oxytocin augmentation for labor induction at term. The other outcomes of both drugs were similar. However, these findings were based on small-scale trials. Further studies assessing the effectiveness and safety of misoprostol and dinoprostone in selected groups of patients are warranted.     

Controlled-release dinoprostone insert versus Foley catheter for labor induction: a meta-analysis

Objective: To compare the effectiveness and safety of controlled-release dinoprostone insert with Foley catheter balloon for cervical ripening and labor induction.

Methods: PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and China Knowledge Resource Integrated Database were searched. Only randomized controlled trials comparing controlled-release dinoprostone insert with Foley catheter balloon were included. Risk ratio (RR) or mean difference (MD) with 95% con?dence interval (CI) was calculated.

Results: Six studies were included with 731 women received dinoprostone insert and 722 Foley catheter. Time from induction to delivery was significantly shortened in dinoprostone insert group compared to Foley catheter group (MD 5.73 h, 95% CI 1.26–10.20). There were no significant differences in vaginal delivery within 24 h (RR 0.75, 95% CI 0.43–1.30) or cesarean section (RR 0.94, 95% CI 0.80–1.12) between two ripening methods. Dinoprostone insert was related with increased rate of excessive uterine contraction (RR 0.07, 95% CI 0.03–0.19), but less oxytocin use (RR 1.86, 95% CI 1.25–2.77) when compared with Foley catheter.

Conclusions: Induction of labor with controlled-release dinoprostone insert seems to be more effective than Foley catheter. However, the former method causes excessive uterine contraction more frequently.     

Models for the prediction of successful induction of labor based on pre-induction sonographic measurement of cervical length

Objective.?To examine the effect of pre-induction cervical length, parity, gestational age at induction, maternal age and body mass index (BMI) on the possibility of successful delivery in women undergoing induction of labor.

Methods.?In 822 singleton pregnancies, induction of labor was carried out at 35 to 42^?+?6 weeks of gestation. The cervical length was measured by transvaginal sonography before induction. The effect of cervical length, parity, gestational age, maternal age and BMI on the interval between induction and vaginal delivery within 24?hours was investigated using Cox's proportional hazard model. The likelihood of vaginal delivery within 24?hours and risk for cesarean section overall and for failure to progress was investigated using logistic regression analysis.

Results.?Successful vaginal delivery within 24?hours of induction occurred in 530 (64.5%) of the 822 women. Cesarean sections were performed in 161 (19.6%) cases, 70 for fetal distress and 91 for failure to progress. Cox's proportional hazard model indicated that significant prediction of the induction-to-delivery interval was provided by the pre-induction cervical length (HR?=?0.89, 95 % CI 0.88–0.90, p?<?0.0001), parity (HR?=?2.39, 95% CI 1.98–2.88, p?<?0.0001), gestational age (HR?=?1.13, 95% CI 1.07–1.2, p?= <?0.0001) and birth weight percentile (HR?=?0.995, 95% CI 0.99?– 0.995, p?=?0.001), but not by maternal age or BMI. Logistic regression analysis indicated that significant prediction of the likelihood of vaginal delivery within 24?hours was provided by pre-induction cervical length (OR?=?0.86, 95% CI 0.84–0.88, p?<?0.0001), parity (OR?=?3.59, 95% CI 2.47–5.22, p?<?0.0001) and gestational age (OR =?1.19, 95% CI 1.07–1.32, p?= <?0.0001) but not by BMI or maternal age. The risk of cesarean section overall was significantly associated with all the variables under consideration, i.e., pre-induction cervical length (OR?=?1.09, 95% CI 1.06–1.11, p?<?0.0001), parity (OR?=?0.25, 95% CI 0.17–0.38, p?<?0.0001), BMI (OR?=?1.85, 95% CI 1.24–2.74, p?=?0.0024), gestational age (OR?=?0.88, 95% CI 0.78–0.98, p?=?0.0215) and maternal age (OR?=?1.04, 95% CI 1.01–1.07, p?=?0.0192). The risk of cesarean section for failure to progress was also significantly associated with pre-induction cervical length (OR?=?1.11, 95% CI 1.07–1.14, p?<?0.0001), parity (OR?=?0.26, 95% CI 0.15–0.43, p?<?0.0001), gestational age (OR?=?0.83, 95% CI 0.73–0.96, p?=?0.0097) and BMI (OR?=?2.07, 95% CI 1.27–3.37, p?=?0.0036).

Conclusion.?In women undergoing induction of labor, pre-induction cervical length, parity, gestational age at induction, maternal age and BMI have a significant effect on the interval between induction and delivery within 24?hours, likelihood of vaginal delivery within 24?hours and the risk of cesarean section.     

Use of intracervical balloons and chorioamnionitis in term premature rupture of membranes

Objective: To determine whether ripening and induction in patients with term premature rupture of membranes (PROM) via intracervical balloon placement (ICB) increases the risk of chorioamnionitis when compared to women with term PROM ripened and induced with other methods.

Study design: A retrospective cohort study of term singleton gestations undergoing ripening and induction after PROM between July 2009 and June 2012 was conducted. Exposure of interest was ICB placement. Primary outcome of interest was chorioamnionitis. Statistical analysis included bivariate and multivariate techniques.

Results: Of 124 term PROM patients, 42 were ripened by ICB with or without oxytocin (33.9%) and 82 were ripened and induced with oxytocin (66.1%). More women ripened with an ICB were nulliparous (n?=?35, 83.3% ICB versus n?=?44, 53.7% oxytocin, p?=?0.001). Chorioamnionitis was slightly more common in women ripened with ICB and/or oxytocin versus oxytocin alone but difference did not reach statistical significance (p?=?0.10). The rate of cesarean delivery, intrauterine pressure catheter (IUPC) use, and median lengths of membrane rupture and active labor were higher in the ICB group. After adjustment, chorioamnionitis was not correlated with ICB placement but with nulliparity [AOR 12.5 (1.36, 114.6), p?=?0.03] and IUPC use [AOR 4.39 (1.04, 18.5), p?=?0.04].

Conclusion: Nulliparity and IUPC, not ICB placement, were associated with chorioamnionitis.     

An elevated amniotic fluid prostaglandin F2α concentration is associated with intra-amniotic inflammation/infection,and clinical and histologic chorioamnionitis,as well as impending preterm delivery in patients with preterm labor and intact membranes

Objective: To determine whether an elevated amniotic fluid concentration of prostaglandin F_2α (PGF_2α) is associated with intra-amniotic inflammation/infection and adverse pregnancy outcomes in patients with preterm labor and intact membranes.

Materials and methods: The retrospective cohort study included 132 patients who had singleton pregnancies with preterm labor (<?35 weeks of gestation) and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for genital mycoplasmas. Intra-amniotic inflammation was defined by an elevated amniotic fluid matrix metalloproteinase-8 (MMP-8) concentration (>23?ng/mL). PGF_2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF_2α concentration was considered elevated when it was above the 95th percentile among pregnant women at 15–36 weeks of gestation who were not in labor (≥170?pg/mL).

Results: (1) The prevalence of an elevated amniotic fluid PGF_2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF_2α concentration had a significantly higher rate of positive amniotic fluid culture [19% (10/53) versus 5% (4/79); p?=?0.019], intra-amniotic inflammation/infection [49% (26/53) versus 20% (16/79); p?=?0.001], spontaneous preterm delivery, clinical and histologic chorioamnionitis, and funisitis, as well as a higher median amniotic fluid MMP-8 concentration and amniotic fluid white blood cell count and a shorter amniocentesis-to-delivery interval than those without an elevated concentration of amniotic fluid PGF_2α (p?<?0.05 for each); and (3) an elevated amniotic fluid PGF_2α concentration was associated with a shorter amniocentesis-to-delivery interval after adjustment for the presence of intra-amniotic inflammation/infection [hazard ratio 2.1, 95% confidence interval (CI) 1.4–3.1; p?=?0.001].

Conclusion: The concentration of PGF_2α was elevated in the amniotic fluid of 40.2% of patients with preterm labor and intact membranes and is an independent risk factor for intra-amniotic inflammation/infection, impending preterm delivery, chorioamnionitis, and funisitis.     

The influence of obstetric intervention on trends in twin stillbirths: United States, 1989–99

Objective: Although twin stillbirth rates have declined substantially over the past two decades, the contribution of changes in obstetric interventions to reducing twin stillbirths has not been quantified.

Methods: We carried out a retrospective cohort study of twin live births and stillbirths in the United States between 1989 and 1999 (n?=?1?102?212). Changes in the rate of stillbirth (???22 weeks) before and after adjustment for changes in labor induction, Cesarean delivery and sociodemographic factors were estimated through ecological logistic regression analysis. This analysis was based on aggregating data by each state within the United States.

Results: Between 1989 and 1999, rates of labor induction and Cesarean delivery among twin live births increased by 138% (from 5.8% to 13.8%) and 15% (from 48.3% to 55.6%), respectively. These changes were accompanied by a 43% decline in the stillbirth rate between 1989 and 1999 (from 24.4 to 13.9 per 1000 fetuses at risk). After excluding births weighing <?500?g, rates of labor induction among twins at 22–27 weeks', 28–33 weeks' and ??34 weeks' gestation increased by 95%, 131% and 127%, respectively, between 1989 and 1999. Cesarean delivery rates also increased by 55%, 29% and 2% in these same gestational age categories. The 48% (relative risk (RR) 0.52, 95% confidence interval (CI) 0.49–0.55) decline in stillbirth rate between 1989–91 and 1997–99 was reduced to a 25% (RR 0.75, 95% CI 0.72–0.79) decline after adjustment for changes in labor induction and Cesarean delivery. The decline in the rate of twin stillbirths was larger at later gestational ages (at ??32 and ??34 weeks) where the largest absolute increases in labor induction rates were observed.

Conclusions: The use of Cesarean delivery and especially labor induction for twin pregnancies has increased substantially in the United States over the last decade and these changes have been associated with a large decline in the rate of stillbirth among twins.     

Does dystocia during labor pose a risk factor for another non-progressive labor during the subsequent delivery?

Objective: To establish whether failure to progress during labor poses a risk factor for another non-progressive labor (NPL) during the subsequent delivery.

Methods: A retrospective cohort study including singleton pregnancies that failed to progress during the previous labor and resulted in a cesarean section (CS) was conducted. Parturients were classified into three groups for both previous and subsequent labors: CS due to NPL stage I, stage II and an elective CS as a comparison group.

Results: Of 202?462 deliveries, 10?654 women met the inclusion criteria: 3068 women were operated due to NPL stage I and 1218 due to NPL stage II. The comparison group included 6368 women. Using a multivariable logistic regression models, NPL stage I during the previous delivery was found as an independent risk factor for another NPL stage I in the subsequent labor (adjusted odds ratio [OR]?=?2.9; 95% confidence interval [CI]?=?2.4–3.7; p?p?=?0.033; adjusted OR?=?5.3; 95% CI?=?3.7–7.5; p?Conclusion: A previous CS due to a NPL is an independent risk factor for another NPL in the subsequent pregnancy and for recurrent cesarean delivery.     

Postdates induction with an unfavorable cervix and risk of cesarean*

Objective: To determine the risk of cesarean delivery associated with postdates induction (≥41 weeks) compared to term induction (37–40w6d) among women with an unfavorable cervix, and to examine the risk factors associated with cesarean among women undergoing postdates induction.

Methods: A planned secondary analysis of a large prospective cohort study on induction (n?=?854) was performed. Women with a singleton gestation, intact membranes, and an unfavorable cervix (Bishop score of ≤6 and dilation ≤2?cm) who were undergoing a term (≥37 weeks) induction for any indication were included. Women with a prior cesarean were excluded. The primary outcome was cesarean delivery. Relative risk of cesarean was estimated using a modified Poisson’s regression model.

Results: There was a significantly increased risk of cesarean for women undergoing postdates induction (n?=?154) compared to women 37–40w6d (n?=?700), (46.8 versus 26.0%, p?p?Conclusions: Women ≥41 weeks undergoing an induction with an unfavorable cervix are at a significantly increased risk of cesarean compared to women 37–40w6d, with nulliparity, obesity, and cervical dilation <1?cm being independent risk factors. These data can be used to augment patient counseling and support the ongoing discussion regarding the risk of post dates induction.     

Association of smoking with wound complications after cesarean delivery

Objective: To determine whether smoking is an independent risk factor for wound dehiscence after cesarean delivery. Methods: In this case–control study, medical records were reviewed for all patients with wound dehiscence after cesarean delivery during a 7-month period. Wound dehiscence was defined as separation of wound edges requiring treatment. Three control patients without such complications were randomly selected for each case patient. Univariate associations were assessed using t test or Fisher’s exact test; univariate odds ratios (OR) and 95% confidence intervals (CI) were calculated with logistic regression. Multivariate associations were assessed with logistic regression on variables with a univariate association significant at p?≤?0.10. Results: Of 597 cesarean deliveries, 30 cases (5 %) with wound dehiscence were identified. As individual variables, smoking (46.7 vs. 21.1%, p?<?0.01, cases vs. controls), histological chorioamnionitis (27.6 vs. 6.7%, p?<?0.01) and preoperative hematocrit (34.0?±?3.2 vs. 35.4?±?3.4, p?<?0.05) were significantly associated with wound complications. In a multivariate logistic regression model, only smoking (OR 5.32; 95% CI 1.77–15.97, p?<?0.01) and histological chorioamnionitis (OR 5.62; 95% CI 1.43–22.11, p?<?0.01) were independently associated with wound dehiscence. Conclusions: Smoking and histological chorioamnionitis are independently associated with wound dehiscence after cesarean delivery.     

Maternal obesity is associated with chorioamnionitis and earlier indicated preterm delivery among expectantly managed women with preterm premature rupture of membranes

Objective: To determine the association between maternal obesity and delivery due to chorioamnionitis prior to labor onset, among expectantly managed women with preterm premature rupture of membranes (pPROM).

Methods: This was a secondary analysis of a multicenter randomized trial of magnesium sulfate versus placebo to prevent cerebral palsy or death among offspring of women with anticipated delivery at 24–31-week gestation. After univariable analysis, Cox proportional hazard evaluated the association between maternal obesity and chorioamnionitis, while Laplace regression investigated how obesity affects the gestational age at delivery of the first 20% of women developing the outcome of interest.

Results: A total of 164 of the 1942 women with pPROM developed chorioamnionitis prior to labor onset. Obese women had a 60% increased hazard of developing such complication (adjusted HR 1.6, 95%CI 1.1–2.1, p?=?.008), prompting delivery 1.5 weeks earlier, as the 20th survival percentile was 27.2-week gestation (95%CI 26–28.6) among obese as opposed to 28.8 weeks (95%CI 27.4–30.1) (p?=?.002) among nonobese women.

Conclusions: Maternal obesity is a risk factor for chorioamnionitis prior to labor onset. Future studies will determine if obesity is important enough to change the management of latency after pPROM according to maternal BMI.     

Mode of delivery and other pregnancy outcomes of patients with documented scoliosis

The aim of this study was to explore whether scoliosis is a risk factor for adverse obstetric outcomes and specifically for cesarean delivery (CD) and labor dystocia. Association between scoliosis and pregnancy outcome was studied before. Confounding conclusions prevent proper counseling of patients. Appropriate statistical analysis of a suitable cohort is helpful in resolving this issue. A retrospective population-based study comparing all singleton pregnancies of women with and without documented scoliosis was conducted. Deliveries occurred between the years 1988 and 2009. Multiple logistic regression models were used to control for confounders. Out of 229,116 patients which were included in our cohort, 0.043% (n?=?98) had a documented scoliosis. These patients had higher rates of fertility treatments (7.1% vs. 1.6%; p?<?0.001). Scoliosis was found to be significantly associated with labor induction (36.7% vs. 26.3 %; p?=?0.02) and cesarean deliveries (21.4% vs. 13.1%; p?=?0.014). Using multiple logistic regression models, with CD as the outcome variable, controlling for confounders such as nulliparity, labor induction and maternal age, scoliosis was not found to be an independent risk factor for CD (OR?=?1.56, 95% CI 1.9–2.7; p?=?0.121). Scoliosis is not a risk factor for adverse pregnancy outcome, and specifically for labor dystocia.     

Mode of delivery in nulliparous women with gestational hypertension undergoing early term induction of labor

Objective: To evaluate perinatal outcomes in nulliparous women undergoing induction of labor for gestational hypertension at term.

Study design: Retrospective cohort study of nulliparous women with gestational hypertension undergoing induction of labor ≥37 weeks. Mode of delivery and perinatal outcomes were compared for women who delivered at 37^0–6/7, 38^0–6/7, and ≥39^0/7 weeks gestation.

Results: The cohort included 320 women: 67 (21%) at 37^0–6/7, 76 (24%) at 38^0–6/7, and 177 (55%) at ≥39^0/7. There was no increase in cesarean delivery (CD) in women delivering earlier, with 26.9% (37^0–6/7), 19.7% (38^0–6/7) and 29.9% (≥39^0/7) requiring CD (p values?=?0.39). Compared to ≥39 weeks, composite maternal morbidity was lowest in women delivering at 38^0–6/7 (adjusted odds ratio [aOR] 0.45, 95% confidence interval (CI) 0.24–0.84). Composite neonatal morbidity was similar among the groups. When compared to women delivering at ≥39^0/7 weeks, women delivered at 38^0–6/7 were less likely to experience any adverse maternal or neonatal outcome (aOR 0.50, 95% CI 0.28–0.90).

Conclusions: Compared to induction of labor at ≥39 weeks, early term induction of labor was not associated with an increased risk of CD in nulliparous women with gestational hypertension.