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

The influence of changing post-term induction of labour patterns on severe neonatal morbidity

OBJECTIVE

To estimate the influence of changing practice patterns of post-term induction of labour on severe neonatal morbidity.

METHODS

This population-based cohort study used data from the Nova Scotia Atlee Perinatal Database to evaluate the effect of post-term induction of labour on stillbirth and neonatal mortality and severe neonatal morbidity in low-risk pregnancies. The study population included all pregnant women ≥ 40 weeks' gestation delivering in Nova Scotia from 1988 to 2008 who underwent induction of labour with a single fetus in cephalic presentation. Major congenital anomalies and pre-existing or severe gestational hypertension and diabetes were excluded. Women delivering post-term from 1994 to 2008 (after the Post-term Pregnancy Trial) were compared with women delivering from 1988 to 1992 to evaluate outcomes with changing maternal characteristics and obstetric practice patterns.

RESULTS

Evaluation and comparison of time epochs (1988 to 1992, 1994 to 1998, 1999 to 2003, and 2004 to 2008) demonstrated an increased risk for perinatal mortality or severe neonatal morbidity, especially low five-minute Apgar score, among both nulliparous and multiparous women. There were no significant differences in the risks for stillbirth or perinatal mortality over time. Comparable relationships were demonstrated in a subgroup of lower risk women.

CONCLUSION

The increase in post-term induction of labour with time is associated with a significant increase in severe neonatal morbidity, especially among infants born to multiparous women. Evaluation of the antepartum and intrapartum management of these low-risk pregnancies may provide additional information to reduce morbidity.

Remote prognosis after primary cesarean delivery: the association of VBACs and recurrent cesarean deliveries with maternal morbidity

PURPOSE

To determine the effects of vaginal birth after cesarean (VBAC) versus repeated cesarean sections (RCS) after a primary cesarean section (CS), on the rate of intraoperative and postpartum maternal morbidity.

PATIENTS AND METHODS

This is a retrospective population-based cohort study. During the study period (1988-2005) there were 200,012 deliveries by 76,985 women at our medical center; 16,365 of them had a primary CS, of which 7429 women delivered a singleton infant after the primary CS, met the inclusion criteria, were included in our study, and were followed for four consecutive deliveries. Patients were divided into three study groups according to the outcome of their consecutive delivery after the primary CS: VBAC (n = 3622), elective CS (n = 1910), or an urgent CS (n = 1897). Survival analysis models were used to investigate the effect of the urgency of CS and the numbers of pregnancy predating the primary CS on peripartum complications.

RESULTS

Women who failed a trial of labor had a higher rate of uterine rupture than those who had a VBAC. Patients who delivered by CS had a higher rate of endometritis than those giving birth vaginally. The rate of cesarean hysterectomy and transfer to other departments increased significantly at the fourth consecutive surgery (P = 0.02 and P = 0.003, respectively). VBAC was associated with a 55% reduction in the risk of intrapartum complications in comparison to a planned CS (hazard ratio [HR] 0.45; 95% confidence interval [CI]: 0.22-0.89. A greater maternal parity at the time of primary CS was associated with lower intrapartum and postpartum morbidities (HR 0.44; 95% CI: 0.24-0.79; HR 0.54; 95% CI: 0.47-0.62, respectively).

CONCLUSIONS

(1) A successful VBAC is associated with a reduction in the intrapartum complications; and (2) maternal morbidity increases substantially from the fourth consecutive cesarean delivery.

Risk factors for blood transfusion in singleton pregnancy deliveries in Taiwan

OBJECTIVE

To investigate risk factors for blood transfusion in pregnancy.

METHODS

In a population-based study, data from all women with singleton pregnancies (n=225 304) admitted for delivery in Taiwanese hospitals in 2002 were obtained from the National Health Insurance claims database. To identify risk factors for blood transfusion, a logistic regression model with generalized estimating equation was used to calculate the adjusted odds ratio (OR) and 95% confidence intervals (CI) for characteristics of the pregnant women, hospitals, clinics, and obstetricians.

RESULTS

The incidence of blood transfusion was 1.43%. Cesarean delivery, vaginal birth after cesarean (VBAC), and repeat cesarean delivery had higher rates of blood transfusion than vaginal delivery, with an OR of 7.2 (95% CI, 6.38-8.02), 4.2 (95% CI, 2.52-6.87), and 5.9 (95% CI, 5.06-6.80), respectively. Other risk factors included extremes of age; pregnancies complicated by prepartum hemorrhage, placenta previa, pre-eclampsia, eclampsia, anemia, or systemic lupus erythematosus; and obstetricians with low or mid-to-low numbers of deliveries.

CONCLUSION

The study has identified risk factors for blood transfusion in pregnancy on the basis of a nationwide database and provides useful information for obstetric practice. For women with a history of cesarean delivery, vaginal delivery might be considered owing to its lower incidence of transfusion.

Severe postpartum haemorrhage and mode of delivery: a retrospective cohort study

OBJECTIVE

To examine the association between intended mode of delivery and severe postpartum haemorrhage.

DESIGN

A retrospective cohort study.

SETTING

Material from a nationwide study in Denmark.

POPULATION

Danish women giving birth in 2001-08.

METHODS

We compared use of red blood cell transfusion by intended mode of delivery in the total population (n = 382 266), in low-risk nulliparous women (n = 147 132) and in women with a previous caesarean delivery (n = 25 156).

MAIN OUTCOME MEASURE

Red blood cell transfusion within 7 days of delivery.

RESULTS

In the total population the crude transfusion rates for women with planned caesarean delivery and intended vaginal delivery were 2.24 and 1.75%. After adjustment for maternal age, body mass index, birthweight, smoking, parity, number of infants and previous caesarean delivery, the risk of red blood cell transfusion was significantly lower in women with planned caesarean delivery compared with intended vaginal delivery (odds ratio 0.82; 95% CI 0.73-0.92; P < 0.01). In low-risk nulliparous women and in women with a previous caesarean delivery the transfusion rates were lower for planned caesarean delivery compared with intended vaginal delivery before and after adjustment.

CONCLUSION

Compared with intended vaginal delivery, planned caesarean delivery was associated with a reduced risk of severe postpartum haemorrhage indicated by use of red blood cell transfusion.

Mechanical dilatation of the cervix at non-labour caesarean section for reducing postoperative morbidity

BACKGROUND

During non-labour caesarean, some obstetricians routinely dilate the cervix from above--using finger, sponge forceps or other instruments because they believe that the cervix of women without labour pain is undilated and may cause obstruction of blood or lochia drainage. However, mechanical cervical dilatation using sponge forceps or a finger during caesarean section may result in contamination by vaginal micro-organisms during dilatation, and increase the risk of infection or cervical trauma.

OBJECTIVES

To determine the effects of mechanical dilatation of the cervix during elective/non-labour caesarean section on postoperative morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2011).

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials comparing intraoperative cervical dilatation using a finger, sponge forceps or other instrument during non-labour caesarean section versus no mechanical dilatation.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, assessed the risk of bias of each included study and extracted data.

MAIN RESULTS

We included three trials with a total of 735 women undergoing elective caesarean section. Of these women, 338 underwent intraoperative cervical dilatation with a double-gloved index digit inserted into the cervical canal to dilate, and 397 did not undergo intraoperative cervical dilatation. Three included trials had moderate-to-high risk of bias. None of the three trials reported our primary outcome of postpartum haemorrhage. In one study of 400 women, blood loss was significantly lower in the cervical dilatation group compared with the no dilatation group (mean difference (MD) -48.49 ml, 95% confidence interval (CI) -88.75 to -8.23). The incidence of febrile morbidity and haemoglobin concentrations in the postoperative period in women undergoing intraoperative cervical dilatation was not significantly different from those who did not receive cervical dilatation (risk ratio (RR) 1.07, 95% CI 0.52 to 2.21 (three trials, 735 women) and MD -0.05 g/dl, 95% CI -0.17 to 0.06 (two trials, 552 women), respectively. There were no significant differences in wound infection, change of haemoglobin level, hematocrit level at postoperative period, endometritis, infectious morbidity, or urinary tract infection. There was a significant difference in operative time, which was reduced in cervical dilatation group (MD -1.84 mins, 95% CI -2.21 to -1.47 (one study, 400 women), but this is of doubtful clinical significance.

AUTHORS' CONCLUSIONS

There was insufficient evidence of mechanical dilatation of the cervix at non-labour caesarean section for reducing postoperative morbidity. Further randomised controlled trials with adequate methodological quality comparing intraoperative cervical dilatation using a finger, sponge forceps or other instrument during non-labour caesarean section versus no mechanical dilatation for reducing postoperative morbidity are needed.

The effect of maternal obesity on the rate of failed induction of labor

OBJECTIVE

The purpose of this study was to quantify the relationship between class of obesity and rate of failed induction of labor.

STUDY DESIGN

Using the Ohio Department of Health's birth certificate database from January 1, 2006, through December 31, 2007, we performed a population-based cohort study that compared failed induction of labor rates between obese and normal-weight women.

RESULTS

The rate of induction is associated with increasing body mass index from 28% in normal-weight women to 34% in class III obese women (body mass index, ≥40 kg/m2). Induction failure rates are also associated with increasing obesity class from 13% in normal-weight women to 29% in class III obese women. Women with class III obesity without a previous vaginal delivery and a macrosomic fetus had the highest rate of failed induction at 80%.

CONCLUSION

Obesity is associated with an increased risk of failed labor induction that appears to be related directly to increasing class of obesity.

Obesity and pregnancy: clinical management of the obese gravida

In recent years, the prevalence of obesity in the United States has risen dramatically, especially among women of reproductive age. Research that has specifically evaluated pregnancy outcomes among obese parturients has allowed for a better understanding of the myriad adverse perinatal complications that are observed with significantly greater frequency in the obese pregnant population. The antepartum, intrapartum, intraoperative, postoperative, and postpartum periods are all times in which the obese pregnant woman is at greater risk for adverse maternal-fetal outcomes, compared with her ideal bodyweight counterpart. Comorbid medical conditions that commonly are associated with obesity further accentuate perinatal risks. All obese pregnant women should be counseled regarding these risks, and strategies should be used to improve perinatal outcome whenever possible. Obese women of reproductive age ideally should be counseled before conception and advised to achieve ideal bodyweight before pregnancy.

Timing of elective repeat cesarean delivery at term and maternal perioperative outcomes

OBJECTIVE

Elective repeat cesarean delivery at 37 or 38 weeks compared with 39 completed weeks of gestation is associated with adverse neonatal outcomes. We assessed whether delivery before 39 weeks is justifiable on the basis of decreased adverse maternal outcomes.

METHODS

We conducted a cohort study of women with live singleton pregnancies delivered by prelabor elective repeat cesarean delivery from 1999 through 2002 at 19 U.S. academic centers. Gestational age was examined by completed weeks (eg, 37 completed weeks=37 0/7-37 6/7 weeks). Maternal outcomes included a primary composite of death, hysterectomy, uterine rupture or dehiscence, blood transfusion, uterine atony, thromboembolic complications, anesthetic complications, surgical injury or need for arterial ligation, intensive care unit admission, wound complications, or endometritis.

RESULTS

Of 13,258 elective repeat cesareans performed at 37 weeks of gestation or later, 11,255 (84.9%) were between 37 0/7 and 39 6/7 weeks (6.3% at 37, 29.5% at 38, and 49.1% at 39 completed weeks), and 15.1% were at 40 0/7 weeks or more. The primary outcome occurred in 7.43% at 37 weeks, 7.47% at 38 weeks and 6.56% at 39 weeks (P for trend test=.09). Delivery before 39 weeks was not associated with a decrease in the primary outcome when compared with delivery at 39 weeks (adjusted odds ratio 1.16; 95% confidence interval 1.00-1.34). Early delivery was associated with increased maternal hospitalization of 5 days or more [1.96 (1.54, 2.49)] but not with a composite of death or hysterectomy or with individual maternal morbidities.

CONCLUSION

Elective repeat cesarean delivery at 37 or 38 weeks is not associated with decreased maternal morbidity.

LEVEL OF EVIDENCE

II.

Contribution of select maternal groups to temporal trends in rates of caesarean section

OBJECTIVE

To estimate the contribution of select maternal groups to temporal trends in Caesarean section (CS) rates.

METHODS

Using the Nova Scotia Atlee Perinatal Database, all deliveries by CS during the 24-year period from 1984 to 2007, at the Women's Hospital, IWK Health Centre were identified. Deliveries by CS were classified into groups using parity (nullipara/multipara), plurality (singleton/multiple), presentation (cephalic/breech/transverse), gestational age (term/preterm), history of previous CS (previous CS/no previous CS), and labour (spontaneous/induced/no labour). CS rates in each group and the contribution of each group to the overall CS rate was determined for three eight-year epochs. The risk of CS in each group over time, accounting for identified maternal, fetal, and obstetric practice factors, was evaluated using logistic regression.

RESULTS

Of 113,016 deliveries, 23,232 (20.6%) were identified as deliveries by CS meeting the inclusion and exclusion criteria. The CS rate rose from 16.8% in 1984 to 1991 to 26.8% in 2000 to 2007 (P < 0.001). The biggest contributors to the overall CS rate in the last study epoch (2000-2007) were nulliparous women with singleton, cephalic, term pregnancies with spontaneous or induced labour; women with singleton, cephalic, term pregnancies with previous CS; and women with breech presentation. Adjusted analyses explained some increases in the rate of CS and demonstrated reduced risks in others.

CONCLUSION

Only some temporally increased CS rates in select maternal groups remain increased after adjusting for confounding variables. The identification of potentially modifiable maternal risk factors, re-evaluation of the indications and techniques for induction of labour in nulliparous women, provision of clinical services for vaginal birth after Caesarean section, and external cephalic version for selected breech presentation are important clinical management areas to consider for safely lowering the Caesarean section rate.

Patients' perspectives on the role of prepared childbirth education in decision making regarding elective labor induction

The purpose of our study was to explore reasons why nulliparous women chose to have an elective labor induction and to identify the influence of prepared childbirth classes on their decision. The study included 1,349 nulliparous women at term who participated in a survey regarding their choices for childbirth, their attendance at prepared childbirth classes, and their experience with labor and birth. Sixty-three percent of women who attended childbirth classes and did not have elective induction reported that classes provided helpful information to assist in their decision-making process. Study results suggest attendance at prepared childbirth classes can be an effective source of information regarding elective labor induction and influential in women's decisions regarding whether or not to have elective labor induction. Women perceive prepared childbirth classes positively and find the information provided valuable.

Pelvic floor consequences of cesarean delivery on maternal request in women with a single birth: a cost-effectiveness analysis

BACKGROUND

The potential benefit in preventing pelvic floor disorders (PFDs) is a frequently cited reason for requesting or performing cesarean delivery on maternal request (CDMR). However, for primigravid women without medical/obstetric indications, the lifetime cost-effectiveness of CDMR remains unknown, particularly with regard to lifelong pelvic floor consequences. Our objective was to assess the cost-effectiveness of CDMR in comparison to trial of labor (TOL) for primigravid women without medical/obstetric indications with a single childbirth over their lifetime, while explicitly accounting for the management of PFD throughout the lifetime.

METHODS

We used Monte Carlo simulation of a decision model containing 249 chance events and 101 parameters depicting lifelong maternal and neonatal outcomes in the following domains: actual mode of delivery, emergency hysterectomy, transient maternal morbidity and mortality, perinatal morbidity and mortality, and the lifelong management of PFDs. Parameter estimates were obtained from published literature. The analysis was conducted from a societal perspective. All costs and quality-adjusted life-years (QALYs) were discounted to the present value at childbirth.

RESULTS

The estimated mean cost and QALYs were $14,259 (95% confidence interval [CI] $8,964-$24,002) and 58.21 (95% CI 57.43-58.67) for CDMR and $13,283 (95% CI $7,861-$23,829) and 57.87 (95% CI 56.97-58.46) for TOL over the combined lifetime of the mother and the child. Parameters related to PFDs play an important role in determining cost and quality of life.

CONCLUSIONS

When a woman without medical/obstetric indications has only one childbirth in her lifetime, cost-effectiveness analysis does not reveal a clearly preferable mode of delivery.

Reconsideration of the costs of convenience: quality, operational, and fiscal strategies to minimize elective labor induction

Elective induction of labor is at an all-time high in the United States despite known associated risks. It can lead to birth of an infant too early, a long labor, exposure to a high-alert medication with its potential side effects, unnecessary cesarean birth, and maternal and neonatal morbidity. There is a cascade of interventions related to elective induction such as an intravenous line, continuous electronic fetal monitoring, confinement to bed, amniotomy, pharmacologic labor stimulating agents, parental pain medications, and regional anesthesia, each with their own set of potential complications and risk of iatrogenic harm. These risks apply to all women having the procedure, however for nulliparous women before 41 weeks of gestation with an unfavorable cervix, the main risk is cesarean birth after unsuccessful labor induction with the potential for maternal and neonatal morbidity and increased healthcare costs. When cesarean occurs, subsequent births are likely to be via cesarean as well. Elective labor induction before 41 weeks is inconsistent with quality perinatal care, and performance of this unnecessary procedure should be minimized. Convenience as the reason for labor induction is contrary to a culture focused on patient safety. A review of current evidence, followed by changes in practice, is warranted to support the safest care possible during labor and birth. Various strategies to reduce the rate of elective induction in the United States are presented.

Do risk factors for elective cesarean section differ from those of cesarean section during labor in low risk pregnancies?

AIMS

As the rate of cesarean sections has continuously increased over the last three decades, we sought to identify the factors related to elective cesarean section (ECS) and cesarean section during labor (LCS) in low risk pregnancies and to determine if they differ for the two types of cesarean.

METHODS

We conducted an observational study that included all maternity units in metropolitan France. Using the sample from the National Perinatal Survey 2003, we included 5393 women who met the criteria of a low risk pregnancy. The odds ratios (OR) corresponding to ECS and LCS were calculated for various characteristics for the women, fetus and maternity units, using a multinomial logistic regression model. For each factor, the adjusted OR corresponding to ECS and LCS were compared using the Wald's test.

RESULTS

The rates of ECS and LCS in our population were 2.9% and 4.3%, respectively. Maternal age >or=30 years, body mass index >or=25 kg/m(2), primiparity and nationality from an African country were associated with an increased risk for both ECS and LCS. Those maternity units registering a low volume of deliveries (<1000/year) and those with a high rate of cesarean section during the previous year had an increased rate of LCS.

CONCLUSION

Women with low risk pregnancies at term may present several factors that appear to create an "environment" favorable for cesarean section, leading to an increase in the likelihood of both ECS and LCS. Furthermore, several characteristics concerning maternity units are associated with an increased likelihood of LCS. Understanding the impact of various factors on the decision about the mode of delivery is essential for obstetrical teams concerned with controlling the progressive increase in the rate of cesarean sections.

Measuring maternal morbidity in routinely collected health data: development and validation of a maternal morbidity outcome indicator

BACKGROUND

As maternal deaths become rare in many countries, severe maternal morbidity has been suggested as a better indicator of quality of care.

OBJECTIVE

To develop and validate an indicator for measuring major maternal morbidity in routinely collected population health datasets (PHDS).

METHODS

First, diagnoses and procedures that might indicate major maternal morbidity were compiled and used to sample possible cases in PHDS; second, a validation study of indicated cases was undertaken by review of birth admission medical records using a nested case-control study approach with 400 possible cases and 800 controls; finally "true" morbidity from the validation study was used to define a maternal morbidity outcome indicator (MMOI) with a high positive predictive value (PPV). Sensitivity, specificity, PPV, negative predictive value (NPV), and exact 95% confidence intervals (95% CI) were weighted by the sampling probabilities.

RESULTS

There were 1184 records available for review. Of 393 possible cases only 188 were confirmed as suffering major morbidity (weighted PPV 47.3%, sensitivity 72.9%) and of the 791 initial noncases, 787 were confirmed as noncases (weighted NPV 99.5%, specificity 98.5%). Revision of the initial indicator with exclusion of noncontributing International Classification of Disease (ICD) codes provided a MMOI with population-weighted rate of 1.5%, PPV 94.6% (95% CI: 72.3-99.9), sensitivity 78.4% (95% CI: 55.2-93.1), specificity 99.9% (95% CI: 99.5-99.9), and 99.5% agreement with "true" morbidity (kappa 0.86).

CONCLUSIONS

PHDS can be used reliably to identify women who suffer a major adverse outcome during the birth admission and have potential for monitoring the quality of obstetric care in a uniform and cost-effective way.

Fetal trauma in term pregnancy

OBJECTIVE

The objective of the study was to determine the incidence and type of fetal trauma in term pregnancy in relation to method of delivery, maternal age, parity, and birthweight.

STUDY DESIGN

From the Nova Scotia Atlee Perinatal Database, fetal trauma was evaluated in all term (37 weeks or longer) singleton fetuses without major anomaly in vertex presentation over a 14-year period (1988-2001).

RESULTS

The overall risk of fetal trauma was low (2.0%); that of major fetal trauma was 0.16%. Major and minor fetal trauma was significantly increased with labor, compared with no labor (adjusted relative risks [RRs], 9.59; 95% confidence interval [CI], 1.34-68.47, and RR, 11.25; 95% CI, 5.05-25.09, respectively). Cesarean delivery was protective for major and minor fetal trauma, compared with vaginal delivery (adjusted RRs, 0.21; 95% CI, 0.12-0.40, and RR, 0.46; 95% CI, 0.39-0.54, respectively).

CONCLUSION

The risk of significant fetal trauma in term pregnancy is very low and most likely to be associated with labor and with assisted vaginal delivery.