Risk of uterine rupture with a trial of labor in women with multiple and single prior cesarean delivery

OBJECTIVE: To determine whether the risk for uterine rupture is increased in women attempting vaginal birth after multiple cesarean deliveries. METHODS: We conducted a prospective multicenter observational study of women with prior cesarean delivery undergoing trial of labor and elective repeat operation. Maternal and perinatal outcomes were compared among women attempting vaginal birth after multiple cesarean deliveries and those with a single prior cesarean delivery. We also compared outcomes for women with multiple prior cesarean deliveries undergoing trial of labor with those electing repeat cesarean delivery. RESULTS: Uterine rupture occurred in 9 of 975 (0.9%) women with multiple prior cesarean compared with 115 of 16,915 (0.7%) women with a single prior operation (P = .37). Multivariable analysis confirmed that multiple prior cesarean delivery was not associated with an increased risk for uterine rupture. The rates of hysterectomy (0.6% versus 0.2%, P = .023) and transfusion (3.2% versus 1.6%, P < .001) were increased in women with multiple prior cesarean deliveries compared with women with a single prior cesarean delivery attempting trial of labor. Similarly, a composite of maternal morbidity was increased in women with multiple prior cesarean deliveries undergoing trial of labor compared with those having elective repeat cesarean delivery (odds ratio 1.41, 95% confidence interval 1.02-1.93). CONCLUSION: A history of multiple cesarean deliveries is not associated with an increased rate of uterine rupture in women attempting vaginal birth compared with those with a single prior operation. Maternal morbidity is increased with trial of labor after multiple cesarean deliveries, compared with elective repeat cesarean delivery, but the absolute risk for complications is small. Vaginal birth after multiple cesarean deliveries should remain an option for eligible women. LEVEL OF EVIDENCE: II-2.     

Uterine rupture and risk factors for caesarean delivery following induced labour in women with one previous lower segment caesarean section

Objective: To determine the outcome of induction of labor, specifically incidence of uterine rupture and reliable predictors of repeat caesarean delivery, in women undergoing induction of labor after previous caesarean section. Methods: A review of obstetric and perinatal records of 167 women who had their labor induced after one transverse lower uterine incision performed at previous caesarean delivery in a referral tertiary hospital in Nigeria between January 2006 and December 2009. Results: The incidence of uterine rupture was 2.4%. Independent risk factors for repeat caesarean delivery were absence of prior vaginal delivery (OR 3.7; 95% CI 1.9–7.1), duration of latent phase >2?h (OR 4.3; 95% CI 1.7–11.2), postdated pregnancy (OR 2.2; 95% CI 1.1–4.0) and previous caesarean for non-recurrent indication (OR 2.1; 95% CI 1.1–4.0). Conclusion: Choice of appropriate delivery option for this cohort of women based on the identified risk factors is essential to minimize the incidence of failed vaginal birth and its associated adverse maternal and neonatal outcome.     

Short-term maternal and neonatal outcomes by mode of delivery. A case-controlled study

OBJECTIVE: Side-by-side comparisons of short-term maternal and neonatal outcomes for spontaneous vaginal delivery, instrumental vaginal delivery, planned caesarean section and caesarean section during labor in patients matched for clinical condition, age, and week of gestation are lacking. This case-controlled study was undertaken to evaluate short-term maternal and neonatal complications in a healthy population at term by mode of delivery. STUDY DESIGN: Four groups of healthy women, with antenatally normal singleton pregnancies at term, who underwent instrumental vaginal delivery (no. 201), spontaneous delivery (no. 402), planned caesarean section without labor (no. 402) and caesarean section in labor (no. 402) have been retrospectively selected. Outcome measures were maternal and neonatal short-term complications. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Maternal complications were mostly associated with forceps-assisted and vacuum-assisted instrumental deliveries (OR: 6.9; 95% CI: 2.9-16.4 and OR 3.0; 95% CI 1.1-8.8, respectively, versus spontaneous deliveries). No significant differences in overall complications were observed between spontaneous vaginal deliveries and caesarean sections, whether planned or in labor. By comparison with caesarean sections in labor, instrumental deliveries significantly increased the risk of complications (OR: 3.2; 95% CI: 1.6-6.5). Neonatal complications were also mostly correlated with forceps-assisted and vacuum-assisted instrumental deliveries (OR: 3.5; 95% CI: 1.9-6.7 and OR 3.8; 95% CI 2.0-7.4, respectively, versus spontaneous deliveries). By comparison with caesarean sections in labor, instrumental vaginal deliveries significantly increased the risk of complications (OR: 4.2; 95% CI: 2.4-7.4). CONCLUSIONS: In healthy women with antenatally normal singleton pregnancies at term, instrumental deliveries are associated with the highest rate of short-term maternal and neonatal complications.     

Fertility outcomes of IVF/ICSI after Caesarean section: a cohort study

Research questionThe study objective was to evaluate the impact of a previous Caesarean section on fertility outcomes in women undergoing IVF/intracytoplasmic sperm injection (ICSI).DesignA retrospective cohort study was designed that included 1793 women undergoing IVF/ICSI who had had a previous delivery from January 2015 to December 2016. The primary outcome was live birth. Secondary outcomes were implantation, clinical pregnancy, miscarriage, ectopic pregnancy, multiple pregnancy and perinatal complications.ResultsOf the 1793 women included, 796 had had a previous Caesarean section and 997 a previous vaginal delivery. Propensity score matching in a 1:1 ratio resulted in 538 women per group. Compared with women with a previous vaginal delivery, women with a previous Caesarean section had a lower live birth rate (30.1% versus 38.1%, odds ratio [OR] 0.70, 95% confidence interval [CI] 0.54–0.90) and a higher miscarriage rate (25.9% versus 17.5%, OR 1.65, 95% CI 1.06–2.56). Among other secondary outcomes, implantation rates were 32.9% and 37.1% (OR 0.83, 95% CI 0.69–1.01), and clinical pregnancy rates were 42.4% and 46.8% (OR 0.84, 95% CI 0.66–1.06), in the Caesarean section group and vaginal delivery group, respectively. There were no statistically significant differences in terms of ectopic pregnancy, multiple pregnancy or perinatal outcomes between the groups. Further adjustment for confounders did not change the result of the primary outcome (OR 0.64, 95% CI 0.49–0.84).ConclusionsWomen undergoing IVF/ICSI who have had a previous Caesarean section have a lower live birth rate and a higher miscarriage rate than those with a previous vaginal delivery.     

Comparison of vaginal and cesarean section delivery for fetuses in breech presentation

OBJECTIVES: Our purpose was to evaluate the perinatal mortality and morbidity of deliveries with fetuses presenting by the breech comparing outcomes of two groups according to mode of delivery: vaginal and cesarean section. RESULTS: Of 756 fetuses studied, 271 were delivered vaginally and 485 by cesarean section. In infants weighing > or = 1500 grams, "further corrected" mortality and morbidity rates were low and similar for both delivery routes: one neonatal death (NNM) in each. Among very low birth weight (VLBW) infants (< 1500 grams) the "further corrected" mortality rate was higher in the vaginal group: 57.4%, and 18.0% in abdominal deliveries (odds ratio [OR] = 6.1, 95% CI: 3.1 to 12.1). Likewise, rate of depression at five minutes were higher in the vaginal group (p < 0.001). However, the average fetal weight among the vaginal deliveries VLBW (787 grams) was 250 grams less than in the cesarean section group (1040 grams). After adjustment for fetal weight, gestational age, and other prognostic variables the odds ratio for neonatal death was no longer statistically significant (adjusted OR = 2.1, 95% CI: 0.9 to 5.2, p = 0.105). Comparison of planned vaginal delivery with elective cesarean section yielded smaller differences (adjusted OR for neonatal death = 1.3, 95% CI: 0.6 to 2.9, p = 0.525). CONCLUSION: The poor perinatal outcomes of breech delivered infants are due primarily to VLBW, congenital malformations, and premature labor. Although abdominal delivery had a lower NNM rate than vaginal delivery, the difference was not significant after adjustment for confounding factors. The results confirm the findings of a previously analyzed similar series delivered at our institution between 1980 and 1987. They suggest that, with appropriate technique, abdominal delivery is not mandatory in breech presentation.     

Risk factors for arrest of descent during the second stage of labor.

OBJECTIVE: To define obstetrical risk factors for arrest of descent during the second stage of labor and to determine perinatal outcome. STUDY DESIGN: All singleton, vertex, term deliveries with an unscarred uterus, between the years 1988 and 1999 were included. Univariable and multivariable analysis were performed to investigate independent risk factors associated with arrest of descent during the second stage of labor and the perinatal outcome. RESULTS: The study included 93266 deliveries, of these 1545 (1.7%) were complicated with arrest of descent during the second stage of labor. Using a multivariable analysis, the following obstetric risk factors were found to be significantly associated with arrest of descent: nulliparity (OR=7.8, 95% CI=6.9-8.7; P<0.001), birth weight >4 kg (OR=2.3, 95% CI=1.9-2.8; P<0.001), epidural analgesia (OR=1.8, 95% CI=1.6-2.0; P<0.001), hydramnios (OR=1.6, 95% CI=1.3-2.0; P<0.001), hypertensive disorders (OR=1.5, 95% CI=1.3-1.8; P<0.001), gestational diabetes A1 and A2 (OR=1.5, 95% CI=1.2-1.8; P<0.001), male gender (OR=1.4, 95% CI=1.2-1.5; P<0.001), premature rupture of membranes (PROM, OR=1.3, 95% CI=1.04-1.6; P=0.021), and induction of labor (OR=1.2, 95% CI=1.02-1.4; P=0.030). Deliveries complicated by arrest of descent resulted in cesarean section in 20.6%, vacuum extraction in 74.0%, and forceps delivery in 5.4%. Newborns delivered after arrest of descent during the second stage of labor had significantly higher rates of low Apgar scores (<7) at 1 and 5 min, as compared to the controls (12.7 vs. 2.1%, P<0.001; and 0.9 vs. 0.2%, P<0.001, respectively). Nevertheless, no significant differences were noted between the groups regarding perinatal mortality (0.38 vs. 0.44%; P=0.759). CONCLUSIONS: Major risk factors for arrest of descent during the second stage of labor were nulliparity, fetal macrosomia, epidural analgesia, hydramnios, hypertensive disorders and gestational diabetes mellitus. These risk factors should be carefully evaluated during pregnancy in order to actively manage high-risk pregnancies.     

Factors predicting severe perineal trauma during childbirth: role of forceps delivery routinely combined with mediolateral episiotomy

OBJECTIVE: Anal sphincter injury and its sequelae are a recognized complication of vaginal childbirth. The aim of the present study was to identify risk factors for third- and fourth-degree perineal tears in patients undergoing either spontaneous or vaginal-assisted delivery by forceps routinely combined with mediolateral episiotomy. STUDY DESIGN: We retrospectively reviewed 5377 vaginal deliveries based on the analysis of the obstetric database and patient records of our department during a 5-year period from 1999 to 2003. Cases and control subjects were chosen randomly and patients' records were reviewed for the following variables: maternal age, parity, gestational age, tobacco use, gestational diabetes or pregnancy-induced hypertension, use of peridural anesthesia, duration of first and second stages of labor, use of mediolateral episiotomy, forceps combined with mediolateral episiotomy, induction of labor, infant head diameter, shoulder circumference, and birth weight. RESULTS: Of 5044 spontaneous vaginal deliveries 32 (0.6%) and of 333 assisted vaginal deliveries 14 (4.2%) patients sustained a perineal defect involving the external sphincter. An univariate analysis of these 46 cases and 155 randomly selected control subjects showed that low parity (P = .003; Mann-Whitney U test), prolonged first and second stages of labor (P = .001, P = .001), high birth weight (P = .031), episiotomy (P = .004; Fisher exact test), and forceps delivery (P = .002) increased the risk for sphincter damage. In multivariate regression models, only high birth weight (P = .004; odds ratio [OR] 1.68, 1.18-2.41, 95% confidence interval [CI]), and forceps delivery combined with mediolateral episiotomies (P < .001; OR 5.62, 2.16-14.62, 95% CI) proved to be independent risk factors. There was a statistical significant interaction of birth weight and head circumference (P = .012; OR 0.99, 0.98-0.99, 95% CI). Although the use of episiotomy conferred an increased risk toward a higher likelihood of severe perineal trauma, it did not reach statistical significance (P = .06; OR 2.15, 0.97-4.76, 95% CI). CONCLUSIONS: In consistence with previous reports, women who are vaginally delivered of a large infant are at a high risk for sphincter damage. Although the rate of these complications was surprisingly low in vaginally assisted childbirth, the use of forceps, even if routinely combined with mediolateral episiotomy, should be minimized whenever possible.     

Impact of sociodemographic and hospital factors on attempts at vaginal birth after cesarean delivery

OBJECTIVE: To estimate the clinical and nonclinical factors associated with whether a patient attempts a trial of labor after previous cesarean delivery or elects to have a repeat cesarean delivery. METHODS: We conducted a retrospective, cohort study comparing all women with previous low transverse cesarean delivery who attempted a trial of labor with those who elected to have a repeat cesarean delivery. Data from 17 hospital sites for the period 1995-1998 were included, for a total of 15,172 patients. Bivariate, site-adjusted, and multivariable logistic regression analyses were used. RESULTS: Odds of trial of labor by hospital were not uniform in the unadjusted or adjusted analyses. The odds of trial of labor decreased significantly with increasing age, gravidity, and number of previous cesarean deliveries. Medicaid patients had higher odds of trial of labor than did privately insured patients (odds ratio [OR] 1.37 [95% confidence interval (CI) 1.20, 1.55]). Patients with nonrecurrent indication for previous cesarean delivery had generally higher odds of trial of labor than did those with a recurrent indication. Black women were more likely to attempt trial of labor than were white women (OR 2.17 [95% CI 1.83, 2.56] for those with a nonrecurrent indication). CONCLUSION: Clinical and nonclinical factors influence rates of attempted vaginal birth after cesarean delivery.     

Has improved health care provision impacted on the obstetric outcome in teenage women?

Objective: To determine the obstetric outcome in teenage women managed in the recent decade with easily accessible health care provision. Methods: In a retrospective cohort study, maternal demographics, underlying medical conditions, obstetric complications, preterm birth, type of labor, mode of delivery, and perinatal mortality were compared between 1505 women aged ≤19 years (study group) with 10,320 women aged 20–24 years (comparison group), who were carrying singleton pregnancies beyond 24 weeks of gestation and managed in our hospital between January 1998 and June 2008. Results: The study and comparison groups accounted for 2.2% and 15.1% respectively of the total deliveries. Despite comparable health status and rates of other obstetric complications, teenage women was associated with birth <34 weeks (aOR 2.45, 95% CI 1.67–3.60), birth at 34–36 weeks (aOR 2.13, 95% CI 1.71–2.65), and reduced instrumental vaginal (aOR 0.62, 95% CI 0.50–0.77) and caesarean (aOR 0.79, 95% CI 0.64–0.97) delivery, without increase in perinatal mortality. Conclusions: Teenage women had increased preterm birth, despite improved health care provision, nutrition, and similar incidence of other obstetric complications, but the obstetric and perinatal outcome remained favorable.     

Accidental out-of-hospital delivery as an independent risk factor for perinatal mortality

OBJECTIVE: To determine maternal characteristics and perinatal outcomes of unattended out-of-hospital deliveries. STUDY DESIGN: A population-based study including all singleton deliveries between 1988 and 1999. Maternal characteristics and pregnancy outcomes of accidental out-of-hospital births were compared with those of women who delivered in the hospital. Multiple logistic regression analysis was performed to investigate independent risk factors for out-of-hospital deliveries. Another model was constructed to assess the independent risk of out-of-hospital delivery for perinatal mortality. RESULTS: The incidence of unattended, out-of-hospital deliveries was 2% (2,328/114,938). Multiparity, Bedouin ethnicity and lack of prenatal care were independently associated with out-of-hospital deliveries. Parturients who delivered out of hospital had a significantly lower rate of previous cesarean deliveries. Perinatal mortality was significantly higher among out-of-hospital deliveries, and those newborns were significantly more likely to be small for gestational age as compared to newborns with in-hospital births. In a multivariable model investigating risk factors for perinatal mortality, out-of-hospital delivery was an independent risk factor for perinatal mortality. Other significant risk factors were Bedouin ethnicity and lack of prenatal care. CONCLUSION: Accidental out-of-hospital birth, associated with multiparity, Bedouin ethnicity and lack of prenatal care, is an independent risk factor for perinatal mortality.     

Induction of labor after one prior cesarean: predictors of vaginal delivery

OBJECTIVE: To estimate the characteristics most associated with vaginal birth in patients undergoing induction of labor after 1 prior cesarean delivery. METHODS: All patients who presented for induction of labor from 1996 to 2001 with a history of 1 prior cesarean delivery were identified. Relevant demographic and obstetric data were abstracted from the charts. Univariate analysis was used to identify predictive factors associated with vaginal birth after cesarean. Binary logistic regression was further used to identify which factors were independently associated with the outcome measure. RESULTS: Of the 429 women included in the study, 334 (77.9%) had a successful trial of labor. In the final binary logistic regression equation, prior vaginal delivery (odds ratio [OR] 3.75; 95% confidence interval [CI] 1.96, 7.18) remained independently associated with an increased chance of a vaginal delivery after a trial of labor. Conversely, prior cesarean delivery for dystocia (OR 0.46; 95% CI 0.27, 0.79), induction on or past the estimated date of delivery (OR 0.46; 95% CI 0.27, 0.78), need for cervical ripening (OR 0.35; 95% CI 0.20, 0.61), and maternal gestational or preexisting diabetes (OR 0.16; 95% CI 0.06, 0.40) were all factors associated with a decreased likelihood of achieving a successful trial of labor. CONCLUSION: Several factors are available which may assist in identifying patients with the best chance of vaginal delivery after an induction of labor in the presence of a prior low-transverse cesarean scar. LEVEL OF EVIDENCE: II-2     

Progestational agents to prevent preterm birth: a meta-analysis of randomized controlled trials

OBJECTIVE: To perform an updated systematic review with meta-analysis to further elucidate the efficacy of progestational agents for the prevention of preterm births in patients at elevated risk. DATA SOURCES: Computerized databases, references in published studies, and textbook chapters in all languages were used to identify randomized controlled trials (RCTs) evaluating the use of progestational agents for the prevention of preterm births in women at elevated risk. METHODS OF STUDY SELECTION: We identified RCTs that compared progestational agents with placebo for patients at risk for preterm birth and evaluated at least one of the following: delivery before 37 weeks of gestation, birth weight less than 2,500 g, threatened preterm labor, respiratory distress syndrome, and perinatal mortality. The primary outcomes assessed were preterm delivery and perinatal mortality. TABULATION, INTEGRATION, AND RESULTS: Ten studies met inclusion criteria for this review. For each study with binary outcomes, an odds ratio (OR) with 95% confidence intervals (CIs) was calculated for selected outcomes. Homogeneity was tested across the studies. Compared with women allocated to receive placebo, those who received progestational agents had lower rates of preterm delivery (26.2% versus 35.9%; OR 0.45, 95% CI 0.25-0.80). Similar results were noted when comparing patients who were specifically treated with 17alpha-hydroxyprogesterone caproate (29.3% versus 40.9%; OR 0.45, 95% CI 0.22-0.93). Additionally, subjects allocated to receive 17alpha-hydroxyprogesterone caproate had lower rates of birth weights less than 2,500 g (OR 0.50, 95% CI 0.36-0.71). No differences in rates of hospital admissions for threatened preterm labor or perinatal mortality were noted for subjects receiving progestational agents in general or for those receiving only 17alpha-hydroxyprogesterone caproate specifically. CONCLUSION: The use of progestational agents and 17alpha-hydroxyprogesterone caproate reduced the incidence of preterm birth and low birth weight newborns.     

Association between prior vaginal birth after cesarean and subsequent labor outcome

Objective: To estimate the effect of prior successful vaginal birth after cesarean (VBAC) on the rate of uterine rupture and delivery outcome in women undergoing labor after cesarean.

Methods: A retrospective cohort study of all women attempting labor after cesarean delivery in a university-affiliated tertiary-hospital (2007–2014) was conducted. Study group included women attempting vaginal delivery with a history of cesarean delivery and at least one prior VBAC. Control group included women attempting first vaginal delivery following cesarean delivery. Primary outcome was defined as the rate of uterine rupture. Secondary outcomes were delivery and maternal outcomes.

Results: Of 62,463 deliveries during the study period, 3256 met inclusion criteria. One thousand two hundred and eleven women had VBAC prior to the index labor and 2045 underwent their first labor after cesarean. Women in the study group had a significantly lower rate of uterine rupture 9 (0.7%) in respect to control 33 (1.6%), p?=?.036, and had a higher rate of successful vaginal birth (96 vs. 84.9%, p?p?=?.04).

Conclusions: In women attempting labor after cesarean, prior VBAC appears to be associated with lower rate of uterine rupture and higher rate of successful vaginal birth.     

Maternal and perinatal outcome in varying degrees of anemia.

OBJECTIVES: To analyze the maternal and perinatal outcome in varying degrees of anemia. METHODS: A total of 447 pregnant women were divided into group I (Hb>11 g%, n=123 women), group II (Hb 9-10.9 g%, n=214 women), group III (Hb 7-8.9 g%, n=79 women) group IV (Hb<7 g%, n=31 women). Their maternal and perinatal outcome, mode of delivery, duration of labor and postpartum complications were noted and analyzed using multiple logistic regression to calculate odds ratios (95% CI) for duration of labor, mode of delivery and low birth babies. Chi square or Fisher's exact test was employed for difference in proportions and Student's t-test for testing difference between means. RESULTS: Mean age (27+/-4.25 years) and number of women with parity >3 were highest in group IV. The patients with Hb<8.9 g% had a 4-6-fold higher risk of prolonged labor compared to Hb>11 g%. The odds ratios for abnormal delivery (cesarean and operative vaginal deliveries) showed a 4.8-fold higher risk (95% CI 1.82, 12.7) in patients with Hb 相似文献   

Impact of Episiotomy During Operative Vaginal Delivery on Obstetrical Anal Sphincter Injuries

ObjectiveThe purpose of this study was to describe associations between episiotomy at the time of forceps or vacuum-assisted delivery and obstetrical anal sphincter injuries (OASIS).MethodsThis population-based retrospective cohort study used delivery information from a provincial perinatal clinical database. Full-term, singleton, in-hospital, operative vaginal deliveries of vertex-presenting infants from April 1, 2006 to March 31, 2016 were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between episiotomy and third- or fourth-degree lacerations were calculated in multiple logistic regression models (Canadian Task Force Classification II-2).ResultsEpisiotomy was performed in 34% of 52 241 operative vaginal deliveries. OASIS occurred in 21% of forceps deliveries and 7.6% of vacuum deliveries. Episiotomy was associated with increased odds of severe perineal lacerations for vacuum deliveries among women with (OR 2.48; 95% CI 1.96–3.13) and without (OR 1.12; 95% CI 1.02–1.22) a prior vaginal delivery. Among forceps deliveries, episiotomy was associated with increased odds of OASIS for those with a previous vaginal delivery (OR 1.52; 95% CI 1.12–2.06), but it was protective for women with no previous vaginal delivery (OR 0.73; 95% CI 0.67–0.79). Midline compared with mediolateral episiotomy increased the odds of OASIS in forceps deliveries (OR 2.73; 95% CI 2.37–3.13) and vacuum deliveries (OR 1.94; 95% CI 1.65–2.28).ConclusionIn conclusion, results suggest that episiotomy should be used with caution, particularly among women with a previous vaginal delivery and in the setting of vacuum-assisted delivery. Episiotomy may protect against OASIS in forceps-assisted deliveries for women without a prior vaginal delivery.     

Maternal morbidity associated with cesarean delivery without labor compared with spontaneous onset of labor at term

OBJECTIVE: To estimate the maternal morbidity associated with cesarean deliveries performed at term without labor compared with morbidity associated with spontaneous labor. METHODS: A 14-year, population-based, cohort study (1988-2001) using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in nulliparous women at term undergoing spontaneous labor for planned vaginal delivery with singleton, cephalic presentation and nulliparous women delivering by cesarean without labor. RESULTS: From a total of 18,435 pregnancies, which satisfied inclusion and exclusion criteria, 721 were cesarean deliveries without labor. There were no maternal deaths or transfers for intensive care. There was no difference in wound infection, blood transfusion, or intraoperative trauma. Women undergoing cesarean deliveries without labor were more likely to have puerperal febrile morbidity (relative risk [RR] 2.2; 95% confidence interval [CI] 1.1, 4.5; P=.03), but were less likely to have early postpartum hemorrhage (RR 0.6; 95% CI 0.4, 0.9; P=.01) compared with women entering spontaneous labor. Subgroup analyses of maternal outcomes in women delivering by spontaneous and assisted vaginal delivery and cesarean delivery in labor were also performed. The highest morbidity was found in the assisted vaginal delivery and cesarean delivery in labor groups. CONCLUSION: The increased maternal morbidity in elective cesarean delivery compared with spontaneous onset of labor is limited to puerperal febrile morbidity. Maternal morbidity is increased after assisted vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor.     

Pregnancy outcome in women with pruritus gravidarum

OBJECTIVE: To investigate obstetric risk factors and pregnancy outcome in women with pruritus gravidarum who delivered during a 15-year period. METHODS: A population-based study comparing all pregnancies in women with and without pruritus gravidarum delivered between 1988 and 2002 was conducted. A multivariable logistic regression model was constructed in order to find independent risk factors associated with pruritus gravidarum. RESULTS: During the study period there were 159,197 deliveries, of which 376 (0.2%) occurred in patients with pruritus gravidarum. Using a multivariable analysis, the following conditions were found to be significantly associated with pruritus gravidarum: twin pregnancies, fertility treatments, diabetes mellitus and nulliparity. No significant differences were noted between the groups regarding perinatal outcomes, such as birth weight, low Apgar scores or perinatal mortality. Pruritus gravidarum was associated with higher rates of labor induction, and accordingly those fetuses were more likely to be delivered by cesarean delivery. CONCLUSION: Pruritus gravidarum, associated with multiple gestations, fertility treatments, diabetes mellitus and nulliparity, is not associated with adverse perinatal outcomes. However, there are higher rates of labor induction and cesarean delivery.     

Neonatal Mortality for Primary Cesarean and Vaginal Births to Low‐Risk Women: Application of an “Intention‐to‐Treat” Model

ABSTRACT: Background: The percentage of United States births delivered by cesarean section continues to increase, even for women considered to be at low risk for the procedure. The purpose of this study was to use an “intention‐to‐treat” methodology, as recommended by a National Institutes of Health conference, to examine neonatal mortality risk by method of delivery for low‐risk women. Methods: Low‐risk births were singleton, term (37–41 weeks’ gestation), vertex births, with no reported medical risk factors or placenta previa and with no prior cesarean section. All U.S. live births and infant deaths for the 1999 to 2002 birth cohorts (8,026,415 births and 17,412 infant deaths) were examined. Using the intention‐to‐treat methodology, a “planned vaginal delivery” category was formed by combining vaginal births and cesareans with labor complications or procedures since the original intention in both cases was presumably a vaginal delivery. This group was compared with cesareans with no labor complications or procedures, which is the closest approximation to a “planned cesarean delivery” category possible, given data limitations. Multivariable logistic regression was used to model neonatal mortality as a function of delivery method, adjusting for sociodemographic and medical risk factors. Results: The unadjusted neonatal mortality rate for cesarean deliveries with no labor complications or procedures was 2.4 times that for planned vaginal deliveries. In the most conservative model, the adjusted odds ratio for neonatal mortality was 1.69 (95% CI 1.35–2.11) for cesareans with no labor complications or procedures, compared with planned vaginal deliveries. Conclusions: The finding that cesarean deliveries with no labor complications or procedures remained at a 69 percent higher risk of neonatal mortality than planned vaginal deliveries is important, given the rapid increase in the number of primary cesarean deliveries without a reported medical indication. (BIRTH 35:1 March 2008)     

Obstetric anal sphincter lacerations

OBJECTIVE: To estimate the frequency of obstetric anal sphincter laceration and to identify characteristics associated with this complication, including modifiable risk factors. METHODS: A population-based, retrospective study of over 2 million vaginal deliveries at California hospitals was performed, using information from birth certificates and discharge summaries for 1992 through 1997. We excluded preterm births, stillbirths, breech deliveries, and multiple gestations. The main outcome measure was obstetric anal sphincter laceration (third and fourth degree). RESULTS: The frequency of anal sphincter lacerations was 5.85% (95% confidence interval [CI] 5.82, 5.88), decreasing significantly from 6.35% (95% CI 6.27, 6.43) in 1992 to 5.43% (95% CI 5.35, 5.51) in 1997 (P <.01). Using logistic regression analysis, we identified primiparity as the dominant risk factor (odds ratio [OR] for women with prior vaginal birth 0.15; 95% CI 0.14, 0.15). Birth weight over 4000 g was also highly significant (OR 2.17; 95% CI 2.07, 2.27). Lacerations occurred more often among women of certain racial and ethnic groups: Indian women (OR 2.5; 95% CI 2.23, 2.79) and Filipina women (OR 1.63; 95% CI 1.50, 1.77) were at highest risk. Episiotomy decreased the likelihood of third-degree lacerations (OR 0.81; 95% CI 0.78, 0.85), but increased the risk of fourth-degree lacerations (OR 1.12; 95% CI 1.05, 1.19). Operative delivery increased the risk of sphincter laceration, with vacuum delivery (OR 2.30; 95% CI 2.21, 2.40) presenting a greater risk than forceps delivery (OR 1.45; 95% CI 1.37, 1.52). CONCLUSION: Anal sphincter lacerations are strongly associated with primiparity, macrosomia, and operative vaginal delivery. Of the modifiable risk factors, operative vaginal delivery remains the dominant independent variable.     

Impact of collaborative management and early admission in labor on method of delivery

OBJECTIVE: This study compared the effects of early admission in labor and perinatal care provider on delivery method. Higher spontaneous vaginal delivery rates for certified nurse midwives as compared with physicians have been reported in observational studies and randomized clinical trials. Certified nurse midwives, with their more expectant approach to labor management, would be expected to admit women later in labor than obstetricians. METHODS: Prospective cohort study of 2,196 low-risk pregnancies, with singleton, vertex infants admitted in spontaneous labor. Independent and joint effects of perinatal care provider and cervical dilation at admission on delivery method were evaluated. Confounding was addressed using restriction and multiple regression. RESULTS: Fewer (23.4%) women in collaborative care were admitted in early labor (< 4 cm cervical dilation) than women managed by obstetricians (95% CI = -27.6 to -19.2). Obstetrician care had 9% to 30% fewer spontaneous vaginal deliveries. Women admitted early in labor also had 6% to 34% fewer spontaneous vaginal deliveries. Evaluation of joint effects suggested that interaction between obstetrician provider and earlier admission increased the risk of operative delivery. CONCLUSION: Later admission in labor (at 4 cm or greater cervical dilation) and management of perinatal care by certified nurse midwives in collaboration with obstetricians increased the rate of spontaneous vaginal delivery in low-risk women.