Variation in the Nulliparous, Term, Singleton, Vertex Cesarean Delivery Rate

OBJECTIVE

To estimate the contributions of patient and health care provider-hospital characteristics to the variation in the frequency of nulliparous, term, singleton, vertex cesarean delivery in a multi-institutional U.S. cohort.

METHODS

We performed a secondary analysis of the multicenter Assessment of Perinatal Excellence cohort of 115,502 mother and neonatal pairs who were delivered at 25 hospitals between March 2008 and February 2011. Women met inclusion criteria if they were nulliparous and delivered a singleton in vertex presentation at term. Hospital ranks for nulliparous, term, singleton, vertex cesarean delivery frequency were determined after risk adjustment. The fraction of variation in nulliparous, term, singleton, vertex cesarean delivery frequency attributable to patient and health care provider-hospital characteristics was assessed using hierarchical logistic regression.

RESULTS

Of the 115,502 deliveries in the initial cohort, 38,275 nulliparous, term, singleton, vertex deliveries met inclusion criteria. The median hospital nulliparous, term, singleton, vertex cesarean delivery frequency was 25.3% with a range from 15.0% to 35.2%. The majority of hospitals (16/25) changed rank quintiles after risk adjustment; overall the changes in rank were not statistically significant (P=.53). Patient characteristics accounted for 24% of the nulliparous, term, singleton, vertex cesarean delivery variation. The analyzed health care provider-hospital characteristics were not significantly associated with cesarean delivery frequency.

CONCLUSION

Although patient characteristics accounted for some of the variation in nulliparous, term, singleton, vertex cesarean delivery frequency and accounting for case mix had implications for hospital cesarean delivery rankings, the majority of the variation was not explained by the characteristics evaluated. These findings emphasize the importance of continued efforts to understand aspects of obstetric care, including case mix, that contribute to cesarean delivery variation.

Defining failed induction of labor

BACKGROUND

While there are well-accepted standards for the diagnosis of arrested active-phase labor, the definition of a "failed" induction of labor remains less certain. One approach to diagnosing a failed induction is based on the duration of the latent phase. However, a standard for the minimum duration that the latent phase of a labor induction should continue, absent acute maternal or fetal indications for cesarean delivery, remains lacking.

OBJECTIVE

The objective of this study was to determine the frequency of adverse maternal and perinatal outcomes as a function of the duration of the latent phase among nulliparous women undergoing labor induction.

STUDY DESIGN

This study is based on data from an obstetric cohort of women delivering at 25 US hospitals from 2008 through 2011. Nulliparous women who had a term singleton gestation in the cephalic presentation were eligible for this analysis if they underwent a labor induction. Consistent with prior studies, the latent phase was determined to begin once cervical ripening had ended, oxytocin was initiated, and rupture of membranes had occurred, and was determined to end once 5-cm dilation was achieved. The frequencies of cesarean delivery, as well as of adverse maternal (eg, postpartum hemorrhage, chorioamnionitis) and perinatal (eg, a composite frequency of seizures, sepsis, bone or nerve injury, encephalopathy, or death) outcomes, were compared as a function of the duration of the latent phase (analyzed with time both as a continuous measure and categorized in 3-hour increments).

RESULTS

A total of 10,677 women were available for analysis. In the vast majority (96.4%) of women, the active phase had been reached by 15 hours. The longer the duration of a woman's latent phase, the greater her chance of ultimately undergoing a cesarean delivery (P < .001, for time both as a continuous and categorical independent variable), although >40% of women whose latent phase lasted ≥18 hours still had a vaginal delivery. Several maternal morbidities, such as postpartum hemorrhage (P < .001) and chorioamnionitis (P < .001), increased in frequency as the length of latent phase increased. Conversely, the frequencies of most adverse perinatal outcomes were statistically stable over time.

CONCLUSION

The large majority of women undergoing labor induction will have entered the active phase by 15 hours after oxytocin has started and rupture of membranes has occurred. Maternal adverse outcomes become statistically more frequent with greater time in the latent phase, although the absolute increase in frequency is relatively small. These data suggest that cesarean delivery should not be undertaken during the latent phase prior to at least 15 hours after oxytocin and rupture of membranes have occurred. The decision to continue labor beyond this point should be individualized, and may take into account factors such as other evidence of labor progress.

Neonatal Morbidity of Small- and Large-for-Gestational-Age Neonates Born at Term in Uncomplicated Pregnancies

OBJECTIVE

To compare morbidity among small-for-gestational-age (SGA; birth weight less than the 10th percentile for gestational age), appropriate-for-gestational-age (AGA; birth weight 10th to 90th percentile; reference group), and large-for-gestational-age (LGA; birth weight greater than the 90th percentile) neonates in apparently uncomplicated pregnancies at term (37 weeks of gestation or greater).

METHODS

This secondary analysis, derived from an observational obstetric cohort of 115,502 deliveries, included women with apparently uncomplicated pregnancies of nonanomalous singletons who had confirmatory ultrasound dating no later than the second trimester and who delivered between 37 0/7 and 42 6/7 weeks of gestation. We used two different composite neonatal morbidity outcomes: hypoxic composite neonatal morbidity for SGA and traumatic composite neonatal morbidity for LGA neonates. Log Poisson relative risks (RRs) with 95% CIs adjusted for potential confounding factors (nulliparity, body mass index, insurance status, and neonatal sex) were calculated.

RESULTS

Among the 63,436 women who met our inclusion criteria, SGA occurred in 7.9% (n=4,983) and LGA in 8.3% (n=5,253). Hypoxic composite neonatal morbidity was significantly higher in SGA (1.1%) compared with AGA (0.7%; adjusted RR 1.44, 95% CI 1.07-1.93) but similar between LGA (0.6%) and AGA (adjusted RR 0.84, 95% CI 0.58-1.22). Traumatic composite neonatal morbidity was significantly higher in LGA (1.9%) than AGA (1.0%; adjusted RR 1.88, 95% CI 1.51-2.34) but similar in SGA (1.3%) compared with AGA (adjusted RR 1.28, 95% CI 0.98-1.67).

CONCLUSION

Among women with uncomplicated pregnancies, hypoxic composite neonatal morbidity is more common with SGA neonates and traumatic-composite neonatal morbidity is more common with LGA neonates.

17-alpha Hydroxyprogesterone caproate did not reduce the rate of recurrent preterm birth in a prospective cohort study

BACKGROUND

17-alpha Hydroxyprogesterone caproate for prevention of recurrent preterm birth is recommended for use in the United States.

OBJECTIVE

We sought to assess the clinical effectiveness of 17-alpha hydroxyprogesterone caproate to prevent recurrent preterm birth ≤35 weeks compared to similar births in our obstetric population prior to the implementation of 17-alpha hydroxyprogesterone caproate.

STUDY DESIGN

This was a prospective cohort study of 17-alpha hydroxyprogesterone caproate in our obstetric population. The primary outcome was the recurrence of birth ≤35 weeks for the entire study cohort compared to a historical referent rate of 16.8% of recurrent preterm birth in our population. There were 3 secondary outcomes. First, did 17-alpha hydroxyprogesterone caproate modify a woman's history of preterm birth when taking into account her prior number and sequence of preterm and term births? Second, was recurrence of preterm birth related to 17-alpha hydroxyprogesterone caproate plasma concentration? Third, was duration of pregnancy modified by 17-alpha hydroxyprogesterone caproate treatment compared to a prior preterm birth?

RESULTS

From January 2012 through March 2016, 430 consecutive women with prior births ≤35 weeks were treated with 17-alpha hydroxyprogesterone caproate. Nearly two thirds of the women (N = 267) began injections ≤18 weeks and 394 (92%) received a scheduled weekly injection within 10 days of reaching 35 weeks or delivery. The overall rate of recurrent preterm birth was 25% (N = 106) for the entire cohort compared to the 16.8% expected rate (P = 1.0). The 3 secondary outcomes were also negative. First, 17-alpha hydroxyprogesterone caproate did not significantly reduce the rates of recurrence regardless of prior preterm birth number or sequence. Second, plasma concentrations of 17-alpha hydroxyprogesterone caproate were not different (P = .17 at 24 weeks; P = .38 at 32 weeks) between women delivered ≤35 weeks and those delivered later in pregnancy. Third, the mean (±SD) interval in weeks of recurrent preterm birth before 17-alpha hydroxyprogesterone caproate use was 0.4 ± 5.3 weeks and the interval of recurrent preterm birth after 17-alpha hydroxyprogesterone caproate treatment was 0.1 ± 4.7 weeks (P = .63). A side effect of weekly 17-alpha hydroxyprogesterone caproate injections was an increase in gestational diabetes. Specifically, the rate of gestational diabetes was 13.4% in 17-alpha hydroxyprogesterone caproate-treated women compared to 8% in case-matched controls (P = .001).

CONCLUSION

17-alpha Hydroxyprogesterone caproate was ineffective for prevention of recurrent preterm birth and was associated with an increased rate of gestational diabetes.

Cell-Free Total and Fetal DNA in First Trimester Maternal Serum and Subsequent Development of Preeclampsia

Objective The objective of this study was to assess the relationship between first trimester cell-free total and fetal DNA in maternal plasma and the subsequent development of preeclampsia. Study Design Nested case-control study of patients enrolled in the Combined Antioxidant and Preeclampsia Prediction Studies prediction study of 175 women who did and 175 women who did not develop preeclampsia. The predictive values of cell-free total and fetal DNA and the subsequent development of preeclampsia were measured using receiver operating characteristic curves. Results Cell-free total DNA was higher in African American (median; 25-75%; 6.15; 0.14-28.73; p = 0.02) and Hispanic (4.95; 0.20-26.82; p = 0.037) compared with white women (2.33; 0.03-13.10). Levels of cell-free total DNA were also associated with maternal body mass index (BMI) (p = 0.02). Cell-free total DNA levels were similar between women who later developed preeclampsia (3.52; 0.11-25.3) and controls (3.74; 0.12-21.14, p = 0.96). Conclusion There is no significant difference in levels of cell-free total DNA in the first trimester in women who subsequently develop preeclampsia. Levels of cell-free total DNA in the first trimester are increased in African American and Hispanic compared with white women, and levels increase with increasing BMI.

Is Mid-trimester Insulin Resistance Predictive of Subsequent Puerperal Infection? A Secondary Analysis of Randomized Trial Data

Objective The objective of this study was to examine whether there is an association between insulin resistance and subsequent development of puerperal infection by measuring insulin resistance in the mid-trimester using the homeostasis model assessment (HOMA:IR). Methods Secondary analysis of low-risk nulliparas enrolled in a multicenter preeclampsia prevention trial. HOMA:IR was measured on fasting plasma glucose and insulin concentrations among low-risk nulliparas between 22 and 26 weeks' gestation. Median HOMA:IR was compared between women who did and did not develop puerperal infection using Wilcoxon rank sum test. Logistic regression was used to control for potential confounders. Results Of 1,180 women with fasting glucose and insulin available, 121 (10.3%) had a puerperal infection. Median HOMA:IR was higher among those with subsequent puerperal infection (4.3 [interquartile, IQR: 2.2-20.5] vs. 2.6 [IQR: 1.5-6.7], p < 0.0001). After controlling for potentially confounding variables HOMA:IR was only marginally associated with an increased risk of development of puerperal infection, adjusted odds ratio: 1.01 (95% confidence interval: 1.00-1.02; p = 0.04) per unit increase. Elevated HOMA:IR performed poorly as a predictor of puerperal infection, with a positive predictive value of 15% and a negative predictive value of 92%. Conclusion Though associated with an increased risk of puerperal infection, insulin resistance, measured by HOMA:IR, is not a clinically useful predictor of puerperal infection.

Prediction of Spontaneous Preterm Birth Among Nulliparous Women With a Short Cervix

OBJECTIVES

The purpose of this study was to evaluate whether demographic and sonographic factors associated with spontaneous preterm birth among nulliparous women with a cervical length of less than 30 mm could be combined into an accurate prediction model for spontaneous preterm birth.

METHODS

We conducted a secondary analysis of a trial of nulliparous women with a singleton gestation and a cervical length of less than 30 mm on transvaginal sonography between 16 and 22 weeks who lacked other risk factors for spontaneous (eg, prior cervical excisional procedure) or medically indicated (eg, chronic hypertension) preterm birth, who were randomized to either 17α-hydroxyprogesterone caproate treatment or a placebo. Risk factors associated with spontaneous preterm birth within the entire cohort were identified by univariable analysis. Factors significantly associated (P < .05) with spontaneous preterm birth were included in a multivariable logistic regression analysis to determine whether an accurate prediction model could be developed.

RESULTS

Of the 657 randomized patients, 109 (16.6%) had spontaneous preterm birth before 37 weeks' gestation. Logistic regression analysis revealed only cervical length (odds ratio, 1.06 per 1-mm decrease; 95% confidence interval, 1.02-1.10) to be associated with spontaneous preterm birth. The area under the receiver operating characteristic curve based on this regression was low (0.63; 95% confidence interval, 0.58-0.69). Results were similar for the outcome of spontaneous preterm birth before 34 weeks.

CONCLUSIONS

An accurate prediction model for spontaneous preterm birth among nulliparous women with a short cervix could not be developed.

Waist-to-Hip Ratio versus Body Mass Index as Predictor of Obesity-Related Pregnancy Outcomes

Objective In nonpregnant populations the waist-to-hip ratio (WHR) is a better predictor of obesity-related outcomes than body mass index (BMI). Our objective was to determine, in pregnancy, the relationship between these measures of obesity, and large-for-gestational age (LGA) and cesarean delivery (CD). Methods This is a secondary analysis of data from the Combined Antioxidant and Preeclampsia Prediction Study. Women with a WHR of ≥ 0.85 and 0.80 to 0.84 at 9 to 16 weeks gestation were compared with those with a WHR < 0.80. Women with early pregnancy BMI ≥ 30.0 kg/m(2) (obese) and 25.0 to 29.9 kg/m(2) (overweight) were compared with those < 25.0 kg/m(2). LGA was defined as > 90% by Alexander nomogram. Univariable analysis, logistic regression, and receiver operating characteristic curves were used. Results Data from 2,276 women were analyzed. After correcting for potential confounders, only BMI ≥ 30 was significantly associated with LGA (adjusted odds ratio [aOR]: 2.07, 1.35-3.16) while BMI 25.0-29.9 (aOR: 1.5, 0.98-2.28), WHR 0.8-0.84 (aOR: 1.33, 0.83-2.13), and WHR ≥ 0.85 (aOR: 1.05, 0.67-1.65) were not. Risk for CD was increased for women with elevated WHR and with higher BMI compared with normal. Conclusion WHR is not associated with LGA. While BMI performed better than WHR, neither was a strong predictor of LGA or need for CD in low-risk nulliparous women.

The impact of ambient operating room temperature on neonatal and maternal hypothermia and associated morbidities: a randomized controlled trial

BACKGROUND

Neonatal hypothermia is common at the time of cesarean delivery and has been associated with a constellation of morbidities in addition to increased neonatal mortality. Additionally, maternal hypothermia is often uncomfortable for the surgical patient and has been associated with intraoperative and postoperative complications. Various methods to decrease the rates of neonatal and maternal hypothermia have been examined and found to have varying levels of success.

OBJECTIVE

We sought to determine whether an increase in operating room temperature at cesarean delivery results in a decrease in the rate of neonatal hypothermia and associated morbidities.

STUDY DESIGN

In this single-center randomized trial, operating room temperatures were adjusted weekly according to a cluster randomization schedule to either 20°C (67°F), which was the standard at our institution, or 23°C (73°F), which was the maximum temperature allowable per hospital policy. Neonatal hypothermia was defined as core body temperature <36.5°C (97.7°F) per World Health Organization criteria. The primary study outcome was neonatal hypothermia on arrival to the admitting nursery. Measures of neonatal morbidity potentially associated with hypothermia were examined.

RESULTS

From February through July 2015, 791 women who underwent cesarean deliveries were enrolled, resulting in 410 infants in the 20°C standard management group and 399 in the 23°C study group. The rate of neonatal hypothermia on arrival to the admitting nursery was lower in the study group as compared to the standard management group: 35% vs 50%, P < .001. Moderate to severe hypothermia was infrequent when the operating room temperature was 23°C (5%); in contrast such hypothermia occurred in 19% of the standard management group, P < .001. Additionally, neonatal temperature in the operating room immediately following delivery and stabilization was also higher in the study group, 37.1 ± 0.6°C vs 36.9 ± 0.6°C, P < .001. We found no difference in rates of intubation, ventilator use, hypoglycemia, metabolic acidemia, or intraventricular hemorrhage. Fever (temperature >38.0°C or 100.4°F) on arrival to the admitting unit was uncommon and did not differ between the study groups. Maternal temperature on arrival to the operating room was not different between the 2 groups, however by delivery it was significantly lower in the standard management group, 36.2 ± 0.6°C vs 36.4 ± 0.6°C, P < .001. This effect persisted, as maternal temperature on arrival to the postoperative care area was lower in the standard management group, 36.1 ± 0.6°C vs 36.2 ± 0.6°C, P < .001, and the rate of hypothermia was higher, 77% vs 69%, P = .008.

CONCLUSION

A modest increase in operating room temperature at the time of cesarean reduces the rate of neonatal and maternal hypothermia. We did not detect a decrease in neonatal morbidity, but the power to detect a small change in these outcomes was limited.

Second-stage labor: how long is too long?

The management of labor has come under increased scrutiny due to the rapid escalation of cesarean delivery in the United States. A workshop of the Society for Maternal-Fetal Medicine, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the American Congress of Obstetricians and Gynecologists was convened to address the rising cesarean delivery rates and one of their recommendations was that the accepted upper limit of the second stage of labor should be increased to ≥4 hours in nulliparous women with epidural analgesia and to ≥3 hours in parous women with epidural. This led to the inaugural Obstetric Care Consensus series document, "Safe Prevention of the Primary Cesarean Delivery," wherein the workshop recommendations on second-stage labor were promulgated nationally. The result is that the now acceptable maximum length of the second stage of labor exceeds the obstetric precepts that have been in use for >50 years. In this Clinical Opinion, we review the evidence on infant safety, vis-à-vis length of the second stage of labor. Our examination of the evidence begins at the outset of the 20th century and culminates in the very recent (2014) recommendation to abandon the long accepted obstetric paradigm that second-stage labor >3 hours in nulliparous women with labor epidural is unsafe for the unborn infant. We conclude that the currently available evidence fails to support the Obstetric Care Consensus position that longer second-stage labor is safe for the unborn infant. Indeed, the evidence suggests quite the opposite. We suggest that when infant safety is at stake the evidence should be robust before a new clinical road is taken. The evidence is not robust.

Relationship of Early Pregnancy Waist-to-Hip Ratio versus Body Mass Index with Gestational Diabetes Mellitus and Insulin Resistance

OBJECTIVE

To determine the risk of gestational diabetes mellitus (GDM) and insulin resistance (IR) in obesity defined by body mass index (BMI), waist-to-hip ratio (WHR), or both combined.

METHODS

Secondary analysis of a randomized multicenter trial of antioxidant supplementation versus placebo in nulliparous low-risk women to prevent pregnancy associated hypertension. Women between 9 and 16 weeks with data for WHR and BMI were analyzed for GDM (n = 2,300). Those with fasting glucose and insulin between 22 and 26 weeks (n = 717) were analyzed for IR by homeostatic model assessment of IR (normal, ≤ 75th percentile). WHR and BMI were categorized as normal (WHR, < 0.80; BMI, < 25 kg/m(2)); overweight (WHR, 0.8-0.84; BMI, 25-29.9 kg/m(2)); and obese (WHR, ≥ 0.85; BMI ≥ 30 kg/m(2)). Receiver operating characteristic curves and logistic regression models were used.

RESULTS

Compared with normal, the risks of GDM or IR were higher in obese by BMI or WHR. The subgroup with obesity by WHR but not by BMI had no increased risk of GDM. BMI was a better predictor of IR (area under the curve [AUC]: 0.71 [BMI], 0.65 [WHR], p = 0.03) but similar to WHR for GDM (AUC: 0.68 [BMI], 0.63 [WHR], p = 0.18).

CONCLUSION

Increased WHR and BMI in early pregnancy are associated with IR and GDM. BMI is a better predictor of IR compared with WHR. Adding WHR to BMI does not improve its ability to detect GDM or IR.

Prenatal vitamin C and E supplementation in smokers is associated with reduced placental abruption and preterm birth: a secondary analysis

OBJECTIVE

Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking.

DESIGN/SETTING/POPULATION

A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations.

METHODS

We examined the effect of vitamin C/E by smoking status at randomisation using the Breslow-Day test for interaction.

MAIN OUTCOME MEASURES

The trial's primary outcomes were PE and a composite outcome of pregnancy-associated hypertension (PAH) with serious adverse outcomes. Perinatal outcomes included preterm birth and abruption.

RESULTS

There were no differences in baseline characteristics within subgroups (smokers versus nonsmokers) by vitamin supplementation status. The effect of prenatal vitamin C/E on the risk of PE (P = 0.66) or PAH composite outcome (P = 0.86) did not differ by smoking status. Vitamin C/E was protective for placental abruption in smokers (relative risk [RR] 0.09; 95% CI 0.00-0.87], but not in nonsmokers (RR 0.92; 95% CI 0.52-1.62) (P = 0.01), and for preterm birth in smokers (RR 0.76; 95% CI 0.58-0.99) but not in nonsmokers (RR 1.03; 95% CI 0.90-1.17) (P = 0.046).

CONCLUSION

In this cohort of women, smoking was not associated with a reduction in PE or the composite outcome of PAH. Vitamin C/E supplementation appears to be associated with a reduction in placental abruption and preterm birth among smokers.

Neonatal Genetic Variation in Steroid Metabolism and Key Respiratory Function Genes and Perinatal Outcomes in Single and Multiple Courses of Corticosteroids

OBJECTIVE

The aim of the study is to evaluate the association of steroid metabolism and respiratory gene polymorphisms in neonates exposed to antenatal corticosteroids (ACS) with respiratory outcomes, small for gestational age (SGA), and response to repeat ACS.

STUDY DESIGN

This candidate gene study is a secondary analysis of women enrolled in a randomized controlled trial of single versus weekly courses of ACS. Nineteen single nucleotide polymorphisms (SNPs) in 13 steroid metabolism and respiratory function genes were evaluated. DNA was extracted from placenta or fetal cord serum and analyzed with TaqMan genotyping. Each SNP was evaluated for association via logistic regression with respiratory distress syndrome (RDS), continuous positive airway pressure (CPAP)/ventilator use (CPV), and SGA.

RESULTS

CRHBP, CRH, and CRHR1 minor alleles were associated with an increased risk of SGA. HSD11B1 and SCNN1B minor alleles were associated with an increased likelihood of RDS. Carriage of minor alleles in SerpinA6 was associated with an increased risk of CPV. CRH and CRHR1 minor alleles were associated with a decreased likelihood of CPV.

CONCLUSION

Steroid metabolism and respiratory gene SNPs are associated with respiratory outcomes and SGA in patients exposed to ACS. Risks for respiratory outcomes are affected by minor allele carriage as well as by treatment with multiple ACS.

Serious maternal complications after early preterm delivery (24-33 weeks' gestation)

OBJECTIVE

We sought to describe the prevalence of serious maternal complications following early preterm birth by gestational age (GA), delivery route, and type of cesarean incision.

STUDY DESIGN

Trained personnel abstracted data from maternal and neonatal charts for all deliveries on randomly selected days representing one third of deliveries across 25 US hospitals over 3 years (n = 115,502). All women delivering nonanomalous singletons between 23-33 weeks' gestation were included. Women were excluded for antepartum stillbirth and highly morbid conditions for which route of delivery would not likely impact morbidity including nonreassuring fetal status, cord prolapse, placenta previa, placenta accreta, placental abruption, and severe and unstable maternal conditions (cardiopulmonary collapse, acute respiratory distress syndrome, seizures). Serious maternal complications were defined as: hemorrhage (blood loss ≥1500 mL, blood transfusion, or hysterectomy for hemorrhage), infection (endometritis, wound dehiscence, or wound infection requiring antibiotics, reopening, or unexpected procedure), intensive care unit admission, or death. Delivery route was categorized as classic cesarean delivery (CCD), low transverse cesarean delivery (LTCD), low vertical cesarean delivery (LVCD), and vaginal delivery. Association of delivery route with complications was estimated using multivariable regression models yielding adjusted relative risks (aRR) controlling for maternal age, race, body mass index, hypertension, diabetes, preterm premature rupture of membranes, preterm labor, GA, and hospital of delivery.

RESULTS

Of 2659 women who met criteria for inclusion in this analysis, 8.6% of women experienced serious maternal complications. Complications were associated with GA and were highest between 23-27 weeks of gestation. The frequency of complications was associated with delivery route; compared with 3.5% of vaginal delivery, 23.0% of CCD (aRR, 3.54; 95% confidence interval (CI), 2.29-5.48), 12.1% of LTCD (aRR, 2.59; 95% CI, 1.77-3.77), and 10.3% of LVCD (aRR, 2.27; 95% CI, 0.68-7.55) experienced complications. There was no significant difference in complication rates between CCD and LTCD (aRR, 1.37; 95% CI, 0.95-1.97) or between CCD and LVCD (aRR, 1.56; 95% CI, 0.48-5.07).

CONCLUSION

The risk of maternal complications after early preterm delivery is substantial, particularly in women who undergo cesarean delivery. Obstetricians need to be prepared to manage potential hemorrhage, infection, and intensive care unit admission for early preterm births requiring cesarean delivery.

Continuous Spinal Analgesia for Labor and Delivery: An Observational Study with a 23-Gauge Spinal Catheter

BACKGROUND

The aim of the study was to assess postdural puncture headache, pain relief, motor blockade, and success rate of conversion to cesarean delivery anesthesia of a 23-gauge spinal catheter (Wiley Spinal®) for labor analgesia.

METHODS

After insertion of the spinal catheter, intrathecal bupivacaine 2.5 mg was administered, followed by patient-controlled intrathecal analgesia (basal infusion of 0.0625% bupivacaine with fentanyl 2 μg/mL at a rate of 2 mL/h, demand bolus 1 mL, lockout interval 20 minutes). Bupivacaine 0.5%, up to 25 mg, was administered via the catheter along with fentanyl 20 μg for cesarean delivery anesthesia, if necessary. The catheter was removed after delivery or after 12 hours, whichever was longer.

RESULTS

One hundred thirteen women were enrolled. In 12 women (11%), the catheter was not successfully inserted or maintained in position. Continuous spinal analgesia was used in 101 women. Three women (2.6%, 95% confidence interval, 0.7%-8.1%) developed postdural puncture headache. There were 83 spontaneous, 12 operative vaginal, and 18 cesarean deliveries. Of the 18 cesarean deliveries, 16 had continuous spinal analgesia when the decision was made to perform a cesarean delivery; conversion from labor analgesia to cesarean anesthesia was successful in 15 women (94%, 95% confidence interval, 67.7%-99.7%).

CONCLUSIONS

The 23-gauge spinal catheter can be used for analgesia for labor. It can also be converted to surgical anesthesia for cesarean deliveries. Further studies are warranted to determine whether the spinal catheter will be a useful addition to the neuraxial techniques available for obstetric anesthesia care.