Salivary progesterone and estriol among pregnant women treated with 17-alpha-hydroxyprogesterone caproate or placebo

OBJECTIVE

The objectives of the study was to determine whether salivary progesterone (P) or estriol (E3) concentration at 16-20 weeks' gestation predicts preterm birth or the response to 17alpha-hydroxyprogesterone caproate (17OHPC) and whether 17OHPC treatment affected the trajectory of salivary P and E3 as pregnancy progressed.

STUDY DESIGN

This was a secondary analysis of a clinical trial of 17OHPC to prevent preterm birth. Baseline saliva was assayed for P and E3. Weekly salivary samples were obtained from 40 women who received 17OHPC and 40 who received placebo in a multicenter randomized trial of 17OHPC to prevent recurrent preterm delivery.

RESULTS

Both low and high baseline saliva P and E3 were associated with a slightly increased risk of preterm birth. However, 17OHPC prevented preterm birth comparably, regardless of baseline salivary hormone concentrations. 17OHPC did not alter the trajectory of salivary P over pregnancy, but it significantly blunted the rise in salivary E3 as well as the rise in the E3/P ratio.

CONCLUSION

17OHPC flattened the trajectory of E3 in the second half of pregnancy, suggesting that the drug influences the fetoplacental unit.

Randomized trial of preinduction cervical ripening: misoprostol vs oxytocin

OBJECTIVE

The purpose of this study was to compare the vaginal delivery rate in women who undergo labor induction with preinduction misoprostol or oxytocin alone.

STUDY DESIGN

Women with singleton pregnancies and Bishop scores <5 with labor induction at > or = 24 weeks of gestation were eligible; they were assigned randomly to oxytocin alone or preinduction cervical ripening with misoprostol. Labor characteristics, maternal complications, and neonatal outcomes were analyzed.

RESULTS

One hundred sixty-three women received oxytocin, and 164 women received misoprostol. Maternal demographics, pretreatment Bishop scores, and labor analgesia were similar between groups. Vaginal delivery rates were also similar: 87% (n = 141) for oxytocin and 81% (n = 133) for misoprostol. Mean time from treatment to delivery was shorter for the oxytocin group, compared with the misoprostol group (13.1 vs 16.3 hours; P = .005). There was no difference in maternal complications or neonatal outcomes between groups.

CONCLUSION

Preinduction cervical ripening with misoprostol did not improve the vaginal delivery rate and resulted in longer intervals to active labor and delivery. Preinduction cervical ripening with misoprostol may not be necessary.

A randomized, controlled trial of magnesium sulfate for the prevention of cerebral palsy

BACKGROUND

Research suggests that fetal exposure to magnesium sulfate before preterm birth might reduce the risk of cerebral palsy.

METHODS

In this multicenter, placebo-controlled, double-blind trial, we randomly assigned women at imminent risk for delivery between 24 and 31 weeks of gestation to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour, or matching placebo. The primary outcome was the composite of stillbirth or infant death by 1 year of corrected age or moderate or severe cerebral palsy at or beyond 2 years of corrected age.

RESULTS

A total of 2241 women underwent randomization. The baseline characteristics were similar in the two groups. Follow-up was achieved for 95.6% of the children. The rate of the primary outcome was not significantly different in the magnesium sulfate group and the placebo group (11.3% and 11.7%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.77 to 1.23). However, in a prespecified secondary analysis, moderate or severe cerebral palsy occurred significantly less frequently in the magnesium sulfate group (1.9% vs. 3.5%; relative risk, 0.55; 95% CI, 0.32 to 0.95). The risk of death did not differ significantly between the groups (9.5% vs. 8.5%; relative risk, 1.12; 95% CI, 0.85 to 1.47). No woman had a life-threatening event.

CONCLUSIONS

Fetal exposure to magnesium sulfate before anticipated early preterm delivery did not reduce the combined risk of moderate or severe cerebral palsy or death, although the rate of cerebral palsy was reduced among survivors. (ClinicalTrials.gov number, NCT00014989.)

Pregnancy in women with renal disease. Part I: general principles

The purpose of this review is to improve the basis upon which advice on pregnancy is given to women with renal disease and to address issues of obstetric management by drawing upon the accumulated world experience. To ensure the proper rapport between the respect for patient's autonomy and the ethical principle of beneficence, the review attempts to impart up-to-date, evidence-based information on the predictable outcomes and hazards of pregnancy in women with chronic renal disease. The physiology of pregnancy from the perspective of the affected kidney will be discussed as well as the principal predictors of maternal and fetal outcomes and general recommendations of management. The available evidence supports the implication that the degree of renal function impairment is the major determinant for pregnancy outcome. In addition, the presence of hypertension further compounds the risks. On the contrary, the degree of proteinuria does not demonstrate a linear correlation with obstetric outcomes. Management and outcome of pregnancies occurring in women on dialysis and after renal transplant are also discussed. Although the outcome of pregnancies under chronic dialysis has markedly improved in the past decade, the chances of achieving a viable pregnancy are much higher after transplantation. But even in renal transplant recipients, the rate of maternal and fetal complications remains high, in addition to concerns regarding possible adverse effects of immunosuppressive drugs on the developing embryo and fetus.

Pregnancy in women with renal disease. Part II: specific underlying renal conditions

The obstetric outcome in women with kidney disease has improved in recent years due to continuous progress in obstetrics and neonatology, as well as better medical management of hypertension and renal disease. However, every pregnancy in these women remains a high-risk pregnancy. When considering the interaction between renal disease and pregnancy, maternal outcomes are related to the initial level of renal dysfunction more than to the specific underlying disease. With regards to fetal outcomes, though, a distinction may exist between renal dysfunction resulting from primary renal disease and that in which renal involvement is part of a systemic disease. In part II of this review, some specific causes of renal failure affecting pregnancy are considered.

Angiotensin receptor agonistic autoantibodies induce pre-eclampsia in pregnant mice

Pre-eclampsia affects approximately 5% of pregnancies and remains a leading cause of maternal and neonatal mortality and morbidity in the United States and the world. The clinical hallmarks of this maternal disorder include hypertension, proteinuria, endothelial dysfunction and placental defects. Advanced-stage clinical symptoms include cerebral hemorrhage, renal failure and the HELLP (hemolysis, elevated liver enzymes and low platelets) syndrome. An effective treatment of pre-eclampsia is unavailable owing to the poor understanding of the pathogenesis of the disease. Numerous recent studies have shown that women with pre-eclampsia possess autoantibodies, termed AT(1)-AAs, that bind and activate the angiotensin II receptor type 1a (AT(1) receptor). We show here that key features of pre-eclampsia, including hypertension, proteinuria, glomerular endotheliosis (a classical renal lesion of pre-eclampsia), placental abnormalities and small fetus size appeared in pregnant mice after injection with either total IgG or affinity-purified AT(1)-AAs from women with pre-eclampsia. These features were prevented by co-injection with losartan, an AT(1) receptor antagonist, or by an antibody neutralizing seven-amino-acid epitope peptide. Thus, our studies indicate that pre-eclampsia may be a pregnancy-induced autoimmune disease in which key features of the disease result from autoantibody-induced angiotensin receptor activation. This hypothesis has obvious implications regarding pre-eclampsia screening, diagnosis and therapy.

Prediction of uterine rupture associated with attempted vaginal birth after cesarean delivery

OBJECTIVE

The purpose of this study was to develop a model that predicts individual-specific risk of uterine rupture during an attempted vaginal birth after cesarean delivery.

STUDY DESIGN

Women with 1 previous low-transverse cesarean delivery who underwent a trial of labor with a term singleton were identified in a concurrently collected database of deliveries that occurred at 19 academic centers during a 4-year period. We analyzed different classification techniques in an effort to develop an accurate prediction model for uterine rupture.

RESULTS

Of the 11,855 women who were available for analysis, 83 women (0.7%) had had a uterine rupture. The optimal final prediction model, which was based on a logistic regression, included 2 variables: any previous vaginal delivery (odds ratio, 0.44; 95% CI, 0.27-0.71) and induction of labor (odds ratio, 1.73; 95% CI, 1.11-2.69). This model, with a c-statistic of 0.627, had poor discriminating ability and did not allow the determination of a clinically useful estimate of the probability of uterine rupture for an individual patient.

CONCLUSION

Factors that were available before or at admission for delivery cannot be used to predict accurately the relatively small proportion of women at term who will experience a uterine rupture during an attempted vaginal birth after cesarean delivery.

Potential biochemical events associated with initiation of labor

Much of our understanding and knowledge of human parturition has been blurred by conjecture and extrapolation. The limited available data on human parturition reflect the inability to directly experiment with pregnant human subjects. In spite of this obvious impediment and the scarcity of longitudinal data on fundamental physiological changes in human pregnancy, recent reports have generated a better understanding of the synchronous activities leading to labor. The purpose of this review was to organize, in an evidence-based format, the current understanding of maternal physiologic phenomena leading from uterine quiescence to uterine labor activity. Recent discoveries have prompted a revision of pre-existing classical theories on the initiation of parturition, such as the progesterone block theory or the prostaglandins stimulation of the uterotonic action of oxytocin. The presence in the circulation of extrahypothalamic corticotrophin-releasing hormone (CRH) produced by the placenta and myometrium is an inciting unique feature of primate pregnancy and a promising field for research. The concept of anatomical regionalization in labor promotion, including the cervical physiological inflammatory reaction, is also discussed in the review, especially in support of the strong link between inflammatory activation and onset of preterm labor. Understanding the intimate chain of events leading to parturition is critical, and elucidating the interplay of signals and processes that initiate normal labor may help us to understand the abnormal variant, spontaneous preterm labor, and devise efficacious interventions against it.

Autoantibody from women with preeclampsia induces soluble Fms-like tyrosine kinase-1 production via angiotensin type 1 receptor and calcineurin/nuclear factor of activated T-cells signaling

Preeclampsia is a pregnancy-specific hypertensive syndrome that causes substantial maternal and fetal morbidity and mortality. Recent evidence indicates that maternal endothelial dysfunction in preeclampsia results from increased soluble Fms-like tyrosine kinase-1 (sFlt-1), a circulating antiangiogenic protein. Factors responsible for excessive production of sFlt-1 in preeclampsia have not been identified. We tested the hypothesis that angiotensin II type 1 (AT(1)) receptor activating autoantibodies, which occur in women with preeclampsia, contribute to increased production of sFlt-1. IgG from women with preeclampsia stimulates the synthesis and secretion of sFlt-1 via AT(1) receptor activation in pregnant mice, human placental villous explants, and human trophoblast cells. Using FK506 or short-interfering RNA targeted to the calcineurin catalytic subunit mRNA, we determined that calcineurin/nuclear factor of activated T-cells signaling functions downstream of the AT(1) receptor to induce sFlt-1 synthesis and secretion by AT(1)-receptor activating autoantibodies. AT(1)-receptor activating autoantibody-induced sFlt-1 secretion resulted in inhibition of endothelial cell migration and capillary tube formation in vitro. Overall, our studies demonstrate that an autoantibody from women with preeclampsia induces sFlt-1 production via angiotensin receptor activation and downstream calcineurin/nuclear factor of activated T-cells signaling. These autoantibodies represent potentially important targets for diagnosis and therapeutic intervention.

Angiotensin receptors, autoimmunity, and preeclampsia

Preeclampsia is a pregnancy-induced hypertensive disorder that causes substantial maternal and fetal morbidity and mortality. Despite being a leading cause of maternal death and a major contributor to maternal and perinatal morbidity, the mechanisms responsible for the pathogenesis of preeclampsia are poorly understood. Recent studies indicate that women with preeclampsia have autoantibodies that activate the angiotensin receptor, AT1, and that autoantibody-mediated receptor activation contributes to pathophysiology associated with preeclampsia. The research reviewed here raises the intriguing possibility that preeclampsia may be a pregnancy-induced autoimmune disease.

Risk of Uterine Rupture and Adverse Perinatal Outcome at Term After Cesarean Delivery

OBJECTIVE

Current information on the risk of uterine rupture after cesarean delivery has generally compared the risk after trial of labor to that occurring with an elective cesarean delivery without labor. Because antepartum counseling cannot account for whether a woman will develop an indication requiring a repeat cesarean delivery or whether labor will occur before scheduled cesarean delivery, the purpose of this analysis was to provide clinically useful information regarding the risks of uterine rupture and adverse perinatal outcome for women at term with a history of prior cesarean delivery.

METHODS

Women with a term singleton gestation and prior cesarean delivery were studied over 4 years at 19 centers. For this analysis, outcomes from five groups were studied: trial of labor, elective repeat with no labor, elective repeat with labor (women presenting in early labor who subsequently underwent cesarean delivery), indicated repeat with labor, and indicated repeat without labor. All cases of uterine rupture were reviewed centrally to assure accuracy of diagnosis.

RESULTS

A total of 39,117 women were studied. In term pregnant women with a prior cesarean delivery, the overall risk for uterine rupture was 0.32% (125 of 39,117), and the overall risk for serious adverse perinatal outcome (stillbirth, hypoxic ischemic encephalopathy, neonatal death) was 106 of 39,049 (0.27%). The uterine rupture risk for indicated repeat cesarean delivery (labor or without labor) was 7 of 6,080 (0.12%); the risk for elective (no indication) repeat cesarean delivery (labor or without labor) was 4 of 17,714 (0.02%). Indicated repeat cesarean delivery increased the risk of uterine rupture by a factor of 5 (odds ratio 5.1, 95% confidence interval 1.49-17.44). In the absence of an indication, the presence of labor also increased the risk of uterine rupture (4 of 2,721 [0.15%] compared with 0 of 14,993, P<.01). The highest rate of uterine rupture occurred in women undergoing trial of labor (0.74%, 114 of 15,323).

CONCLUSION

At term, the risk of uterine rupture and adverse perinatal outcome for women with a singleton and prior cesarean delivery is low regardless of mode of delivery, occurring in 3 per 1,000 women. Maternal complications occurred in 3-8% of women within the five delivery groups.

Trial of Labor After One Previous Cesarean Delivery for Multifetal Gestation

OBJECTIVE

To estimate success rates and risks with a trial of labor after one previous cesarean delivery for multifetal gestation compared with one previous cesarean delivery for a singleton pregnancy.

METHODS

Patients from the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network Cesarean Registry with one previous cesarean delivery and a current term singleton pregnancy were identified. Cases had one previous cesarean delivery for a multifetal pregnancy. Controls had one previous cesarean delivery for a singleton pregnancy.

RESULTS

Of cases, 556 of 944 (58.9%) attempted a trial of labor. Of controls, 13,923 of 29,329 (47.5%) attempted a trial of labor. The trial of labor success rate was 85.6% among cases and 73.1% among controls (odds ratio 2.19, 95% confidence interval 1.72-2.78). Compared with trial of labor controls, cases had no statistically increased risk of transfusion, endometritis, intensive care unit admissions, uterine rupture, or perinatal complications. Cases in this analysis with a successful trial of labor were more likely to have previously had a successful vaginal birth after cesarean (37.1% compared with 14.1%, P<.001).

CONCLUSION

Women with one previous cesarean delivery for a multifetal gestation have high trial of labor success rates and low complication rates.

Perioperative morbidity and mortality among human immunodeficiency virus infected women undergoing cesarean delivery

OBJECTIVE

To determine whether human immunodeficiency virus (HIV)-infected women have a higher rate of postcesarean morbidity and mortality compared with women without HIV infection.

METHODS

A secondary analysis was performed of women with singleton gestations undergoing cesarean delivery with known HIV status. Data were collected as part of a prospective 4-year (1999-2002) observational study and analyzed using logistic regression. Women were surveyed for a large number of intraoperative complications, common perioperative morbidities, and uncommon maternal complications.

RESULTS

There were 378 HIV-infected and 54,281 uninfected women who met criteria. Patients infected with HIV were more likely to have postpartum endometritis (11.6% compared with 5.8%, P<.001), require a postpartum blood transfusion (4.0% compared with 2.0%, P=.02), develop maternal sepsis (1.1% compared with 0.2%, P<.001), be treated for pneumonia (1.3% compared with 0.3%, P=.001), and to have a maternal death (0.8% compared with 0.1%, P<.001). After controlling for potential confounders, patients with HIV infection were more likely to have one or more postpartum morbidities (odds ratio 1.6, 95% confidence interval 1.2-2.2).

CONCLUSION

Women with HIV infection undergoing cesarean delivery are at increased risk for perioperative morbidity and maternal mortality.

LEVEL OF EVIDENCE

II.

Trial of Vaginal Breech Delivery: Current Role

Breech presentation occurs at term in approximately 3% to 4% of singleton gestations. This presentation is associated with a variety of maternal and fetal conditions including preterm labor, abnormal amniotic fluid volume, hydrocephaly, anencephaly, mullerian anomalies, abnormal placentation, and multifetal gestation. Cesarean delivery has been associated with increased risk of subsequent accreta, placenta previa, hemorrhage, and hysterectomy. The Term Breech Trial initially suggested that planned vaginal breech delivery is associated with increased neonatal morbidity and mortality compared with planned cesarean delivery. Long-term follow-up of these vaginally delivered infants contradict the initial findings. Current debate surrounds the dilemma of whether the untoward complications of cesarean delivery are warranted given uncertain minimal increases in neonatal survival and improvement in neurologic outcome with planned cesarean.

Impact of progesterone on cytokine-stimulated nuclear factor-kappaB signaling in HeLa cells

OBJECTIVE

A key event in the pathways leading to preterm labor may be the activation of nuclear factor-kappaB (NF-kappaB) in the fetal membranes and the cervix. Anti-inflammatory agents, such as the corticosteroids, inhibit the activation of NF-kappaB. We proposed to investigate the effects of progesterone pretreatment on cytokine-stimulated activation of NF-kappaB in HeLa cells, a human cervical epithelial cell line.

METHODS

HeLa cells were pretreated with 10(-7) M progesterone for 24 hours and exposed to 1 ng/mL interleukin-1beta (IL-1beta) for 1 hour. Nuclear and cytosolic extracts were subjected to Western blot analysis using anti-p65 and anti-inhibitory protein-kappaBalpha (anti-IkappaBalpha) antibodies. Densitometric data (n=5) were compared using Kruskal-Wallis test.

RESULTS

Pretreatment with progesterone interfered with IL-1beta-induced IkappaBalpha degradation. However, progesterone pretreatment resulted in a significant decrease in NF-kappaB protein subunit p65 in the cytoplasm. Pretreatment with progesterone did not reduce the amount of nuclear p65 and did not interfere with nuclear translocation of p65.

CONCLUSION

Our observations suggest that any possible role played by progesterone in preterm labor prevention is not exerted through anti-inflammatory mechanisms of NF-kappaB down-regulation.

Development of a Nomogram for Prediction of Vaginal Birth After Cesarean Delivery

OBJECTIVE

To develop a model based on factors available at the first prenatal visit that predicts chance of successful vaginal birth after cesarean delivery (VBAC) for individual patients who undergo a trial of labor.

METHODS

All women with one prior low transverse cesarean who underwent a trial of labor at term with a vertex singleton gestation were identified from a concurrently collected database of deliveries at 19 academic centers during a 4-year period. Using factors identifiable at the first prenatal visit, we analyzed different classification techniques in an effort to develop a meaningful prediction model for VBAC success. After development and cross-validation, this model was represented by a graphic nomogram.

RESULTS

Seven-thousand six hundred sixty women were available for analysis. The prediction model is based on a multivariable logistic regression, including the variables of maternal age, body mass index, ethnicity, prior vaginal delivery, the occurrence of a VBAC, and a potentially recurrent indication for the cesarean delivery. After analyzing the model with cross-validation techniques, it was found to be both accurate and discriminating.

CONCLUSION

A predictive nomogram, which incorporates six variables easily ascertainable at the first prenatal visit, has been developed that allows the determination of a patient-specific chance for successful VBAC for those women who undertake trial of labor.

LEVEL OF EVIDENCE

II.

Outcomes of Induction of Labor After One Prior Cesarean

OBJECTIVE

To compare pregnancy outcomes in women with one prior low-transverse cesarean delivery after induction of labor with pregnancy outcomes after spontaneous labor.

METHODS

This study is an analysis of women with one prior low-transverse cesarean and a singleton gestation who underwent a trial of labor and who were enrolled in a 4-year prospective observational study. Pregnancy outcomes were evaluated according to whether a woman underwent spontaneous labor or labor induction.

RESULTS

Among the 11,778 women studied, vaginal delivery was less likely after induction of labor both in women without and with a prior vaginal delivery (51% versus 65%, P<.001; and 83% versus 88%, P<.001). An increased risk of uterine rupture after labor induction was found only in women with no prior vaginal delivery (1.5% versus 0.8%, P=.02; and 0.6% versus 0.4%, P=.42). Blood transfusion, venous thromboembolism, and hysterectomy were also more common with induction among women without a prior vaginal delivery. No measure of perinatal morbidity was associated with labor induction. An unfavorable cervix at labor induction was not associated with any adverse outcomes except an increased risk of cesarean delivery.

CONCLUSION

Induction of labor in the study population is associated with an increased risk of cesarean delivery in all women with an unfavorable cervix, a statistically significant, albeit clinically small, increase in maternal morbidity in women with no prior vaginal delivery, and no appreciable increase in perinatal morbidity.

LEVEL OF EVIDENCE

II.

Chronic Renal Disease in Pregnancy

The purpose of this review was to examine the impact of varying degrees of renal insufficiency on pregnancy outcome in women with chronic renal disease. Our search of the literature did not reveal any randomized clinical trials or meta-analyses. The available information is derived from opinion, reviews, retrospective series, and limited observational series. It appears that chronic renal disease in pregnancy is uncommon, occurring in 0.03-0.12% of all pregnancies from two U.S. population-based and registry studies. Maternal complications associated with chronic renal disease include preeclampsia, worsening renal function, preterm delivery, anemia, chronic hypertension, and cesarean delivery. The live birth rate in women with chronic renal disease ranges between 64% and 98% depending on the severity of renal insufficiency and presence of hypertension. Significant proteinuria may be an indicator of underlying renal insufficiency. Management of pregnant women with underlying renal disease should ideally entail a multidisciplinary approach at a tertiary center and include a maternal-fetal medicine specialist and a nephrologist. Such women should receive counseling regarding the pregnancy outcomes in association with maternal chronic renal disease and the effect of pregnancy on renal function, especially within the ensuing 5 years postpartum. These women will require frequent visits and monitoring of renal function during pregnancy. Women whose renal disease is further complicated by hypertension should be counseled regarding the increased risk of adverse outcome and need for blood pressure control. Some antihypertensives, especially angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, should be avoided during pregnancy, if possible, because of the potential for both teratogenic (hypocalvaria) and fetal effects (renal failure, oliguria, and demise).

Fetal pulse oximetry and cesarean delivery

BACKGROUND

Knowledge of fetal oxygen saturation, as an adjunct to electronic fetal monitoring, may be associated with a significant change in the rate of cesarean deliveries or the infant's condition at birth.

METHODS

We randomly assigned 5341 nulliparous women who were at term and in early labor to either "open" or "masked" fetal pulse oximetry. In the open group, fetal oxygen saturation values were displayed to the clinician. In the masked group, the fetal oxygen sensor was inserted and the values were recorded by computer, but the data were hidden. Labor complicated by a nonreassuring fetal heart rate before randomization was documented for subsequent analysis.

RESULTS

There was no significant difference in the overall rates of cesarean delivery between the open and masked groups (26.3% and 27.5%, respectively; P=0.31). The rates of cesarean delivery associated with the separate indications of a nonreassuring fetal heart rate (7.1% and 7.9%, respectively; P=0.30) and dystocia (18.6% and 19.2%, respectively; P=0.59) were similar between the two groups. Similar findings were observed in the subgroup of 2168 women in whom a nonreassuring fetal heart rate was detected before randomization. The condition of the infants at birth did not differ significantly between the two groups.

CONCLUSIONS

Knowledge of the fetal oxygen saturation is not associated with a reduction in the rate of cesarean delivery or with improvement in the condition of the newborn. (ClinicalTrials.gov number, NCT00098709 [ClinicalTrials.gov].).

Blood Transfusion and Cesarean Delivery

OBJECTIVE

To evaluate risks for intraoperative or postoperative packed red blood cell transfusion in women who underwent cesarean delivery.

METHODS

This was a 19-university prospective observational study. All primary cesarean deliveries from January 1, 1999, to December 31, 2000, and all repeat cesareans from January 1, 1999, to December 31, 2002, were included. Trained, certified research nurses performed systematic data abstraction. Primary and repeat cesarean deliveries were analyzed separately. Univariable analyses were used to inform multivariable analyses.

RESULTS

A total of 23,486 women underwent primary cesarean delivery, of whom 762 (3.2%) were transfused (median 2 units, 25th% to 75th% 2-3 units). A total of 33,683 women underwent repeat [corrected] cesarean delivery, and 735 (2.2%) were transfused (median 2 units, 25th% to 75th% 2-4 units). Among primary cesareans, general anesthesia (odds ratio [OR] 4.2, 95% confidence interval [CI] 3.5-5.0), placenta previa (OR 4.8, CI 3.5-6.5) and severe (hematocrit less than 25%) preoperative anemia (OR 17.0, CI 12.4-23.3) increased the odds of transfusion. Among repeat cesareans, the risk was increased by general anesthesia (OR 7.2, CI 5.9-8.7), a history of five or more prior cesareans (OR 7.6, CI 4.0-14.3), placenta previa (OR 15.9, CI 12.0-21.0), and severe preoperative anemia (OR 19.9, CI 14.5-27.2).

CONCLUSION

Overall, the risk of transfusion in association with cesarean is low. However, both severe preoperative maternal anemia and placenta previa are associated with markedly increased risks. The former argues for optimizing maternal antenatal iron status to avoid severe anemia and the latter for careful perioperative planning when previa complicates cesarean.

LEVEL OF EVIDENCE

II-2.

The MFMU Cesarean Registry: impact of fetal size on trial of labor success for patients with previous cesarean for dystocia

OBJECTIVE

The purpose of this study was to determine the influence of change in infant birth weight between pregnancies on the outcome of a trial of labor for women whose first cesarean delivery was performed for dystocia.

STUDY DESIGN

Secondary analysis of 7081 patients with 1 previous cesarean delivery and no other deliveries after 20 weeks' gestation, undergoing a trial of labor with a singleton gestation. Cases were classified as dystocia if the listed indication for the cesarean delivery in the first pregnancy was failed induction, cephalo-pelvic disproportion, failure to progress, or failed forceps or vacuum. Outcomes of the trial of labor were correlated with fetal size relative to birth weight in the initial pregnancy for those women whose initial cesarean delivery was for dystocia and those with other indications.

RESULTS

For the cohort being studied (n = 7081), dystocia was the indication for the first cesarean delivery for 3182 (44.9%). Trial of labor resulted in vaginal delivery for 54% of patients whose first cesarean delivery was performed for dystocia, compared with 67% for those with other indications (P < .01). For those whose first cesarean delivery was for dystocia, trial of labor success was correlated with birth weight differences between the pregnancies, with only 38% delivering vaginally if the trial of labor birth weight exceeded the initial pregnancy birth weight by more than 500 g. Using logistic regression and adjusting for other potential confounding factors, the odds of success decreased by 3.8% for each increase of 100 g in birth weight in the trial of labor relative to the first birth weight.

CONCLUSION

For women with previous cesarean delivery for dystocia, increasing birth weight in the subsequent trial of labor relative to the first birth weight diminishes the chances of successful vaginal delivery.

The Maternal-Fetal Medicine Units Cesarean Registry: safety and efficacy of a trial of labor in preterm pregnancy after a prior cesarean delivery

OBJECTIVE

This study was undertaken to compare success rates of vaginal birth after cesarean (VBAC) delivery, and uterine rupture as well as maternal/perinatal outcomes between women with preterm and term pregnancies undergoing trial of labor (TOL), and to compare maternal and neonatal morbidities in those women with preterm pregnancies undergoing a TOL versus repeat cesarean delivery without labor (RCD).

STUDY DESIGN

Prospective 4-year observational study of women with a singleton gestation and a prior cesarean delivery at 19 academic centers. Clinical characteristics, maternal complications and VBAC delivery success for those with a preterm (24(0)-36(6) weeks) TOL, preterm RCD and term TOL (> or = 37 weeks) were analyzed.

RESULTS

Among 3119 preterm pregnancies with prior cesarean delivery, 2338 (75%) underwent a TOL. 15,331 women undergoing TOL at term were also analyzed as a control group. TOL success rates for preterm and term pregnancies were similar (72.8% vs 73.3%, P = .64). Rates of uterine rupture (0.34% vs 0.74%, P = .03) and dehiscence (0.26% vs 0.67%, P = .02) were lower in preterm compared with term TOL. Thromboembolic disease, coagulopathy and transfusion were more common in women undergoing a preterm TOL than those at term. Among women undergoing a preterm TOL, rates of uterine dehiscence, coagulopathy, transfusion, and endometritis were similar to those having a preterm RCD. After controlling for gestational age at delivery and race, neonatal outcomes such as Neonatal Intensive Care Unit (NICU) admission, intraventricular hemorrhage, sepsis, and ventilatory support were similar in both groups except for a higher rate of respiratory distress syndrome in those delivered after a TOL.

CONCLUSION

The likelihood of VBAC success after TOL in preterm pregnancies is comparable to term gestations, with a lower risk of uterine rupture. Perinatal outcomes are similar with preterm TOL and RCD. TOL should be considered as an option for women undergoing preterm delivery with a history of prior cesarean delivery.

Treatment Options for Nausea and Vomiting During Pregnancy

Nausea and vomiting, common symptoms during pregnancy, often are regarded as an unpleasant but normal part of pregnancy during the first and early second trimesters. Nausea and vomiting of pregnancy (NVP) occurs in approximately 75-80% of pregnant women. The exact etiology and pathogenesis of NVP are poorly understood and are most likely multifactorial. Some theories for the etiology of NVP are psychological predisposition, evolutionary adaptation, hormonal stimuli, and Helicobacter pylori infection. Treatment ranges from dietary and lifestyle changes to vitamins, antiemetics, and hospitalization for intravenous therapy. Treatment generally begins with nonpharmacologic interventions; if symptoms do not improve, drug therapy is added. Although NVP has been associated with a positive pregnancy outcome, the symptoms can significantly affect a woman's life, both personally and professionally. Given the substantial health care costs, as well as indirect costs, and the potential decrease in quality of life due to NVP, providers need to acknowledge the impact of NVP and provide appropriate treatment.

G-CSF- and GM-CSF-induced upregulation of CD26 peptidase downregulates the functional chemotactic response of CD34+CD38− human cord blood hematopoietic cells

OBJECTIVE

Cytokine treatment with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and stem cell factor (SCF) is a mainstay of current and future clinical and research protocols for peripheral blood stem cell mobilization, therapeutic care after hematopoietic stem cell transplantation (HSCT), and ex vivo hematopoietic stem and progenitor cell (HSC/HPC) expansion. We have previously shown that the peptidase CD26 (DPPIV/dipeptidylpeptidase IV) negatively regulates HSC/HPC and that inhibition of CD26 improves the chemotactic ability and trafficking of HSC/HPC. We set out to establish whether short-term in vitro G-CSF, GM-CSF, or SCF treatment upregulates CD26 and thereby has a detrimental effect on the chemotactic potential of HSC/HPC that could be reversed by CD26 inhibitor treatment.

MATERIALS AND METHODS

CD34+ or CD34+CD38- cells, a population enriched in HSC, were isolated from human umbilical cord blood and subjected to G-CSF, GM-CSF, or SCF treatment. We then evaluated CD26 expression, CD26 activity, and CXCL12 (SDF-1)-induced migration in the presence or absence of a CD26 inhibitor, Diprotin A.

RESULTS

Treatment with G-CSF and GM-CSF but not SCF upregulates CD26 expression and activity resulting in a CD26 inhibitor-reversible downregulation of CXCL12-induced chemotactic response.

CONCLUSIONS

Short-term in vitro G-CSF and GM-CSF treatment upregulates the peptidase CD26, resulting in downregulation of the functional ability of CD34+CD38- cells to respond to the chemokine CXCL12. This suggests that current and future clinical protocols utilizing G-CSF and GM-CSF may have unforeseen detrimental effects on the trafficking of HSC/HPC during HSCT that can be overcome through the use of CD26 inhibitors.

Maternal morbidity associated with multiple repeat cesarean deliveries

OBJECTIVE

Although repeat cesarean deliveries often are associated with serious morbidity, they account for only a portion of abdominal deliveries and are overlooked when evaluating morbidity. Our objective was to estimate the magnitude of increased maternal morbidity associated with increasing number of cesarean deliveries.

METHODS

Prospective observational cohort of 30,132 women who had cesarean delivery without labor in 19 academic centers over 4 years (1999-2002).

RESULTS

There were 6,201 first (primary), 15,808 second, 6,324 third, 1,452 fourth, 258 fifth, and 89 sixth or more cesarean deliveries. The risks of placenta accreta, cystotomy, bowel injury, ureteral injury, and ileus, the need for postoperative ventilation, intensive care unit admission, hysterectomy, and blood transfusion requiring 4 or more units, and the duration of operative time and hospital stay significantly increased with increasing number of cesarean deliveries. Placenta accreta was present in 15 (0.24%), 49 (0.31%), 36 (0.57%), 31 (2.13%), 6 (2.33%), and 6 (6.74%) women undergoing their first, second, third, fourth, fifth, and sixth or more cesarean deliveries, respectively. Hysterectomy was required in 40 (0.65%) first, 67 (0.42%) second, 57 (0.90%) third, 35 (2.41%) fourth, 9 (3.49%) fifth, and 8 (8.99%) sixth or more cesarean deliveries. In the 723 women with previa, the risk for placenta accreta was 3%, 11%, 40%, 61%, and 67% for first, second, third, fourth, and fifth or more repeat cesarean deliveries, respectively.

CONCLUSION

Because serious maternal morbidity increases progressively with increasing number of cesarean deliveries, the number of intended pregnancies should be considered during counseling regarding elective repeat cesarean operation versus a trial of labor and when debating the merits of elective primary cesarean delivery.

LEVEL OF EVIDENCE

II-2.

Trial of Labor or Repeat Cesarean Delivery in Women With Morbid Obesity and Previous Cesarean Delivery

OBJECTIVE

Assess effects of body mass index (BMI) on trial of labor after previous cesarean delivery and determine whether morbidly obese women have greater maternal and perinatal morbidity with trial of labor compared with elective repeat cesarean delivery.

METHODS

Secondary analysis from a prospective observational study included all term singletons undergoing trial of labor after previous cesarean delivery. Body mass index groups were as follows: normal 18.5-24.9, overweight 25.0-29.9, obese 30.0-39.9, morbidly obese 40.0 kg/m2 or greater, and were compared for failure and maternal and neonatal morbidities. The morbidly obese trial of labor and elective repeat cesarean delivery were compared for maternal and neonatal morbidities. Multivariable logistic regression analysis controlled for confounding variables.

RESULTS

There were 14,142 trial of labor participants and 14,304 elective repeat cesarean delivery participants. Increasing BMI was directly associated with failed trial of labor after previous cesarean delivery: from 15.2% in normal weight (1,344) to 39.3% in morbidly obese (1,638), with combined risk of rupture/dehiscence increasing from 0.9% to 2.1% in morbidly obese women. Among morbidly obese women, trial of labor carried greater than five-fold risk of uterine rupture/dehiscence (2.1% versus 0.4%), almost a two-fold increase in composite maternal morbidity (7.2% versus 3.8%) and five-fold risk of neonatal injury (1.1% versus 0.2%) (fractures, brachial plexus injuries, and lacerations), but no neonatal encephalopathy. Morbidly obese women failing a trial of labor had six-fold greater composite maternal morbidity than those undergoing a successful trial of labor (14.2% versus 2.6%).

CONCLUSION

Body mass index correlates with outcomes in trial of labor after previous cesarean delivery. Morbidly obese women undergoing a trial of labor were at increased risk for failure. Increased BMI was associated with greater composite morbidity and neonatal injury compared with elective repeat cesarean delivery, but absolute morbidities were small. Increased risks should be considered before trial of labor after previous cesarean delivery.

LEVEL OF EVIDENCE

II-2.

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.

From concept to practice: the recent history of preterm delivery prevention. Part II: Subclinical infection and hormonal effects

Under the new cervical insufficiency postulate, the final common pathway theoretically may be influenced by multiple interventions including not only cerclage, but also antibiotics, anti-inflammatory drugs, or progesterone. Since the late 1970s, accumulating evidence has implicated intrauterine infection as a cause of preterm labor. The use of antimicrobial therapy for the prevention of preterm delivery (PTD), although plausible and appealing, has remained largely ineffective so far. A decade of antimicrobial intervention trials to prevent infection-mediated PTD has had disappointing results. Several randomized clinical trials have assessed the role of bacterial vaginosis (BV) treatment in prevention of PTD. The inconsistent results of these trials suggest that other processes, possibly immunomodulation, may be important. Additional factors, still unidentified, pertaining to infectious agent virulence or host immune response modulation, may be responsible for the increased risk of PTD in only a small subset of pregnant women with BV. Even a particular genetic susceptibility was proposed as an intervening factor in the correlation between BV and PTD. Autocrine, paracrine, and endocrine processes in the fetal-placental-uterine unit may contribute to the premature activation of parturitional mechanisms. Progesterone has been used in an attempt to prevent PTD since the 1970s, but the evidence accumulated until the 1990s was fraught by mixed results, and was based mostly on underpowered studies with variable eligibility criteria, including history of spontaneous abortion as an indication for treatment. Two recent randomized, controlled clinical trials restimulated the interest in progesterone supplementation, suggesting that progesterone treatment may influence favorably the rate of preterm delivery, as well as perinatal mortality and morbidity. A major impediment in accepting progesterone as the magic bullet in the prevention of PTD is that its mechanism of action is less well understood than that of all the other prophylactic measures discussed in this review. The optimal formulation, route of administration, dose, and gestational age at initiation have yet to be established. Our ability to quantify prospectively the risk of PTD in a given patient is limited. Moreover, there are limited evidence-based strategies available for prevention of PTD, reflecting our incomplete understanding of the nature of preterm labor. Although an effective instrument in PTD prevention is still elusive, the studies conducted so far have led to a shift in our understanding of cervical insufficiency, infection-mediated PTD, and hormonal influences in human parturition.

From concept to practice: the recent history of preterm delivery prevention. Part I: cervical competence

The prevention of preterm delivery (PTD) is a major desiderate in contemporary obstetrics and a societal necessity. The means to achieve this goal remain elusive, and the research efforts have been punctuated by several ineffective intervention proposals. More recently, new areas of proposed preventive strategy have arisen, focusing on cervical competence, subclinical infection, and hormonal effects. This review, based on a comprehensive and unbiased review of the available literature, will address the rationale and current status of these new concepts of significant clinical interest. We will describe the microcosm of thought and research dedicated to the prevention of PTD during the last 10 years, and the arduous efforts to establish a linkage between predictive observations and therapeutic hypotheses. In its first part, the review will discuss the recently emerging view that regardless of the preterm labor etiology, a common pathway is eventually reached, reflected in cervical changes. The new concept of functional cervical insufficiency is addressed from the perspective of cervical assessment by ultrasound. Although the existing research has not accurately quantified yet the usefulness of ultrasound cervical examination, the technique has become commonplace. Several recent studies have demonstrated a continuum of risk between shorter cervix on ultrasound and higher rate of PTD, leading to the hypothetical argument that women with short cervix on ultrasound might benefit from cervical cerclage. Observational and randomized clinical trials of cerclage as a modality of pregnancy prolongation have provided conflicting results. The relative paucity of data and the conflicting nature of the available evidence dictate caution whenever decisions for cervical monitoring or intervention are made.

Acute hypertensive emergencies in pregnancy

OBJECTIVE

Obstetrical hypertensive emergencies are life-threatening conditions involving significant risk to both the mother and fetus. Aggressive treatment of the maternal hypertensive state requires an initial consideration of the effect of treatment on the fetus, via changes to the uteroplacental circulation with treatment. The challenge then is to correct blood pressure using appropriate, safe pharmacologic agents to prevent catastrophic maternal consequences, while minimizing acute changes to placental perfusion and any corresponding fetal ill effects. Hypertension in pregnancy may be one manifestation of a multiple-system pathologic process, as is the case in preeclampsia. Blood pressure control, along with delivery, will be the first step in treating the renal, hematologic, hepatic, and cardiac dysfunction that can be seen in preeclampsia.

DESIGN

A review of medications most commonly used for hypertensive emergencies in pregnancy.

CONCLUSIONS

Hypertensive emergencies in pregnancy require prompt evaluation and treatment in an intensive care setting to prevent untoward effects to both the fetus and mother.

The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean delivery

OBJECTIVE

The purpose of this study was to determine which factors influence the likelihood of successful trial of labor (TOL) after 1 previous cesarean delivery (CD).

STUDY DESIGN

We performed a multicenter 4-year prospective observational study (1999-2002) of all women with previous CD undergoing TOL. Women with term singleton pregnancies with 1 previous low transverse CD or unknown incision were included for analysis.

RESULTS

Fourteen thousand five hundred twenty-nine women underwent TOL, with 10,690 (73.6%) achieving successful VBAC. Women with previous vaginal birth had an 86.6% success rate compared with 60.9% in women without such a history (odds ratio [OR] 4.2; 95% CI 3.8-4.5; P < .001). TOL success rates were affected by previous indication for CD, need for induction or augmentation, cervical dilation on admission, birth weight, race, and maternal body mass index. Multivariate logistic regression analysis identified as predictive of TOL success: previous vaginal delivery (OR 3.9; 95% CI 3.6-4.3), previous indication not being dystocia (CPD/FTP) (OR 1.7; 95% CI 1.5-1.8), spontaneous labor (OR 1.6; 95% CI 1.5-1.8), birth weight <4000 g (OR 2.0; 95% CI 1.8-2.3), and Caucasian race (OR 1.8, 95% CI 1.6-1.9) (all P < .001). The overall TOL success rate in obese women (BMI > or = 30) was lower (68.4%) than in nonobese women (79.6%) (P < .001), and when combined with induction and lack of previous vaginal delivery, successful VBAC occurred in only 44.2% of cases.

CONCLUSION

Previous vaginal delivery including previous VBAC is the greatest predictor for successful TOL. Previous indication as dystocia, need for labor induction, or a maternal BMI > or = 30 significantly lowers success rates.

Does Progesterone Treatment Influence Risk Factors for Recurrent Preterm Delivery?

OBJECTIVE

To examine how demographic and pregnancy characteristics can affect the risk of recurrent preterm delivery and the how the effectiveness of progesterone treatment for prevention alters these relationships.

METHODS

This was a secondary analysis of a randomized trial of 17alpha-hydroxyprogesterone caproate to prevent recurrent preterm delivery in women at risk. Associations of risk factors for preterm delivery (less than 37 completed weeks of gestation) were examined separately for the women in the 17alpha-hydroxyprogesterone caproate (n = 310) and placebo (n = 153) groups.

RESULTS

Univariate analysis found that the number of previous preterm deliveries and whether the penultimate delivery was preterm were significant risk factors for preterm delivery in both the placebo and progesterone groups. High body mass index was protective of preterm birth in the placebo group. Multivariate analysis found progesterone treatment to cancel the risk of more than 1 previous preterm delivery, but not the risk associated with the penultimate pregnancy delivered preterm. Obesity was associated with lower risk for preterm delivery in the placebo group but not in the women treated with progesterone.

CONCLUSION

The use of 17alpha-hydroxyprogesterone caproate in women with a previous preterm delivery reduces the overall risk of preterm delivery and changes the epidemiology of risk factors for recurrent preterm delivery. In particular, these data suggest that 17alpha-hydroxyprogesterone caproate reduces the risk of a history of more than 1 preterm delivery.

LEVEL OF EVIDENCE

I.

Progesterone for prevention of recurrent preterm birth: impact of gestational age at previous delivery

OBJECTIVE

Preterm birth occurs in 1 of 8 pregnancies and may result in significant morbidity and mortality. 17-alpha hydroxyprogesterone caproate (17-OHP caproate) has been found to be efficacious in reducing the risk of subsequent preterm delivery in women who have had a previous spontaneous preterm birth (sPTB). This analysis was undertaken to evaluate if 17-OHP caproate therapy works preferentially depending on the gestational age at previous spontaneous delivery. We hypothesized that treatment with 17-OHP caproate is more effective in prolonging pregnancy depending on the gestational age of the earliest previous preterm birth (20-27.9, 28-33.9 vs 34-36.9 weeks).

STUDY DESIGN

This was a secondary analysis of 459 women with a previous sPTB enrolled in a randomized controlled trial evaluating 17-OHP caproate versus placebo. Effectiveness of 17-OHP caproate for pregnancy prolongation was evaluated based on gestational age at earliest previous delivery according to clinically relevant groupings (20-27.9, 28-33.9, and 34-36.9 weeks). Statistical analysis included the chi-square, Fisher exact, and Kruskal-Wallis tests, logistic regression, and survival analysis using proportional hazards.

RESULTS

Gestational age at earliest previous delivery was similar between women treated with 17-OHP caproate or placebo (P = .1). Women with earliest delivery at 20 to 27.9 weeks and at 28 to 33.9 weeks delivered at significantly more advanced gestational age if treated with 17-OHP caproate than with placebo (median 37.3 vs 35.4 weeks, P = .046 and 38.0 vs 36.7 weeks, P = .004, respectively) and were less likely to deliver <37 weeks (42% vs 63%, P = .026 and 34% vs 56%, P = .005, respectively). Those with earliest delivery at 34 to 36.9 weeks were not significantly different between 17-OHP caproate or control.

CONCLUSION

17-OHP caproate therapy given to prevent recurrent PTB is associated with a prolongation of pregnancy overall, and especially for women with a previous spontaneous PTB at <34 weeks.

Plasma CRH measurement at 16 to 20 weeks' gestation does not predict preterm delivery in women at high-risk for preterm delivery

OBJECTIVE

The purpose of this study was to examine the utility of a single second-trimester plasma corticotropin-releasing hormone measurement as a marker for preterm delivery in women at high risk for preterm delivery.

STUDY DESIGN

This is an analysis of data from a multicenter placebo-controlled trial designed to evaluate the role of 17 alpha hydroxyprogesterone caproate (17P) in the prevention of recurrent preterm birth. Women with a documented history of a previous spontaneous preterm birth at <37 weeks were enrolled (16-20 wks) and randomly assigned in a 2 to 1 ratio to weekly injections of 17P or matching placebo. Blood was collected before treatment in 170 patients (113 assigned 17P and 57 placebo) who were enrolled at 11 of the 19 centers. Plasma levels of corticotropin-releasing hormone were compared between those who delivered preterm and those delivering at term. Data were analyzed using the Wilcoxon rank-sum test.

RESULTS

The overall rates of preterm birth in this cohort of 170 patients were 35.9% at <37 weeks (31.9% progesterone, 43.9% placebo), and 19.4% at <35 weeks (18.6% vs 21.1%). The median levels of corticotropin-releasing hormone were similar between those delivering at <37 weeks and those delivering > or = 37 weeks (0.39 ng/mL vs 0.37 ng/mL, P = .08). In addition, there were no differences in corticotropin-releasing hormone levels among those who delivered at <35 weeks or > or = 35 weeks (0.36 vs 0.38, P = .90). Moreover, there were no differences in corticotropin-releasing hormone levels among those in the placebo group who delivered at <37 or > or = 37 weeks (0.40 vs 0.41, P = .72) and at <35 or > or = 35 weeks (P = .64).

CONCLUSION

A single measurement of corticotropin-releasing hormone at 16 to 20 weeks' gestation is not a good biomarker for recurrent preterm delivery in patients at high risk for this complication.

Outcomes of term vaginal breech delivery

In December 2001, the American College of Obstetricians and Gynecologists revised their recommendations for breech delivery. These recommendations acknowledge that although a planned vaginal delivery may no longer be appropriate, there are instances in which vaginal breech delivery is inevitable. Moreover, there continues to be patients who for any number of reasons will choose vaginal over cesarean delivery when faced with a fetus in the breech presentation. We sought to review maternal and fetal outcomes in such circumstances when vaginal breech delivery occurs, and compare these outcomes to elective cesarean deliveries for breech presentation. We performed a retrospective review of all singleton breech deliveries at our county hospital from January 2002 through June 2003. We reviewed maternal age, ethnicity, gestational age, gravity, parity, birthweight, mode of delivery, Apgar scores, umbilical arterial blood gases, and maternal and infant complications of both cesarean deliveries and vaginal breech deliveries. Univariate and logistic regression statistical analyses were performed with NCSS software. We had a total of 150 term breech deliveries with gestational ages between 37 and 42 weeks. Of these, 41 were vaginal breech and 109 were cesarean deliveries. Greater than 95% of patients are of Hispanic origin. There were no statistically significant differences in maternal age, ethnicity, gravity, or gestational age. Mean birthweight was significantly lower and parity was significantly higher in the vaginal delivery group. There was also a higher proportion of patients who underwent labor induction/augmentation in the vaginal group. We found no differences in the outcomes of 5-minute Apgar scores, umbilical arterial blood gas values, neonatal intensive care unit admissions, deaths or maternal/fetal complications reported between the two groups. Mean umbilical arterial blood gas values were greater than 7.18 in both groups. Vaginal breech delivery cannot always be avoided. Moreover, at our county hospital several patients continue to choose vaginal breech delivery. Our data would suggest that vaginal breech delivery remains a viable option in selected patients.

Dichorionic twins discordant for thanatophoric dysplasia managed with selective reduction at 20 weeks' gestation: a case report

BACKGROUND

Thanatophoric dysplasia (TD) is a rare and lethal form of skeletal disorder. A MEDLINE search for 1965-2003 yielded only 3 reports of multiple pregnancies discordant for TD. This is the first case report of selective twin reduction for this diagnosis.

CASE

A young woman was seen in consultation at 20 weeks' gestation. Ultrasound examination revealed a twin pregnancy, with ultrasound markers consistent with thanatophoric dysplasia, type II, in twin A. A thick dividing membrane and separated placentas were noted. After counseling, the patient opted for selective termination of twin A. Termination was performed by intracardiac injection of potassium chloride. The pregnancy continued uneventfully until 33 weeks, when spontaneous labor resulted in vaginal delivery of a vigorous female infant, and a mummified, macerated fetus.

CONCLUSION

Selective termination for discordant lethal anomalies can be safely performed when the presence of the anomalous twin increases the risk of a poor perinatal outcome for the apparently normal cotwin.

The Maternal-Fetal Medicine Unit cesarean registry: trial of labor with a twin gestation

OBJECTIVE

The purpose of this study was to identify the success rates and risks in women with a twin pregnancy who attempt a trial of labor after cesarean delivery.

STUDY DESIGN

Cases were identified in the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network's Cesarean Registry with a woman with a twin pregnancy who had had at least 1 previous cesarean delivery.

RESULTS

During the study period (1999-2002), 412 women fulfilled the study criteria, and 226 women had elective repeat cesarean delivery. Of the 186 women (45.1% of total) who attempted a trial of labor, 120 women were delivered successfully (success rate, 64.5%), and 66 women (35.5%) had a failed trial of labor. Thirty of the failed trials of labor involved a vaginal delivery for twin A and cesarean delivery for twin B. Women who attempted a trial of labor with twins had no increased risk of transfusion, endometritis, intensive care unit admissions, or uterine rupture when compared with elective repeat cesarean delivery. Fetal and neonatal complications were uncommon in either group at>or=34 weeks of gestation.

CONCLUSION

A trial of labor with twins after previous cesarean delivery does not appear to increase maternal morbidity. Perinatal morbidity is uncommon at>or=34 weeks of gestation.

Subcutaneous Tissue Reapproximation, Alone or in Combination With Drain, in Obese Women Undergoing Cesarean Delivery

OBJECTIVE

To compare the efficacy of subcutaneous suture reapproximation alone with suture plus subcutaneous drain for the prevention of wound complications in obese women undergoing cesarean delivery.

METHODS

We conducted a multicenter randomized trial of women undergoing cesarean delivery. Consenting women with 4 cm or more of subcutaneous thickness were randomized to either subcutaneous suture closure alone (n = 149) or suture plus drain (n = 131). The drain was attached to bulb suction and removed at 72 hours or earlier if output was less than 30 mL/24 h. The primary study outcome was a composite wound morbidity rate (defined by any of the following: subcutaneous tissue dehiscence, seroma, hematoma, abscess, or fascial dehiscence).

RESULTS

From April 2001 to July 2004, a total of 280 women were enrolled. Ninety-five percent of women (268/280) had a follow-up wound assessment. Both groups were similar with respect to age, race, parity, weight, cesarean indication, diabetes, steroid/antibiotic use, chorioamnionitis, and subcutaneous thickness. The composite wound morbidity rate was 17.4% (25/144) in the suture group and 22.7% (28/124) in the suture plus drain group (relative risk 1.3, 95% confidence interval 0.8-2.1). Individual wound complication rates, including subcutaneous dehiscence (15.3% versus 21.8%), seroma (9.0% versus 10.6%), hematoma (2.2% versus 2.4%), abscess (0.7% versus 3.3%), fascial dehiscence (1.4% versus 1.7%), and hospital readmission for wound complications (3.5% versus 6.6%), were similar (P > .05) between women treated with suture alone and those treated with suture plus drain, respectively.

CONCLUSION

The additional use of a subcutaneous drain along with a standard subcutaneous suture reapproximation technique is not effective for the prevention of wound complications in obese women undergoing cesarean delivery.

Effects of nuchal cord on birthweight and immediate neonatal outcomes

Our objective was to ascertain if nuchal cord is associated with adverse neonatal outcomes. Using a retrospective database of term neonates, outcomes were compared among infants with 0, 1, and 2 or more loops of cord encircling the neck. Of 4426 neonates, 3651 served as controls, 691 had one loop, and 84 had two or more loops. There were no significant differences in the mean birthweight, the frequency of nonreassuring fetal heart rate patterns, operative vaginal deliveries, or 5-minute Apgar scores of < 7. The cesarean delivery rate was significantly different among the three groups and was the highest among the group of women whose fetus had no nuchal cord ( p < 0.01). A nuchal cord at term is not associated with untoward pregnancy outcomes.

Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery

BACKGROUND

The proportion of women who attempt vaginal delivery after prior cesarean delivery has decreased largely because of concern about safety. The absolute and relative risks associated with a trial of labor in women with a history of cesarean delivery, as compared with elective repeated cesarean delivery without labor, are uncertain.

METHODS

We conducted a prospective four-year observational study of all women with a singleton gestation and a prior cesarean delivery at 19 academic medical centers. Maternal and perinatal outcomes were compared between women who underwent a trial of labor and women who had an elective repeated cesarean delivery without labor.

RESULTS

Vaginal delivery was attempted by 17,898 women, and 15,801 women underwent elective repeated cesarean delivery without labor. Symptomatic uterine rupture occurred in 124 women who underwent a trial of labor (0.7 percent). Hypoxic-ischemic encephalopathy occurred in no infants whose mothers underwent elective repeated cesarean delivery and in 12 infants born at term whose mothers underwent a trial of labor (P<0.001). Seven of these cases of hypoxic-ischemic encephalopathy followed uterine rupture (absolute risk, 0.46 per 1000 women at term undergoing a trial of labor), including two neonatal deaths. The rate of endometritis was higher in women undergoing a trial of labor than in women undergoing repeated elective cesarean delivery (2.9 percent vs. 1.8 percent), as was the rate of blood transfusion (1.7 percent vs. 1.0 percent). The frequency of hysterectomy and of maternal death did not differ significantly between groups (0.2 percent vs. 0.3 percent, and 0.02 percent vs. 0.04 percent, respectively).

CONCLUSIONS

A trial of labor after prior cesarean delivery is associated with a greater perinatal risk than is elective repeated cesarean delivery without labor, although absolute risks are low. This information is relevant for counseling women about their choices after a cesarean section.

Characterization of corticosteroid redosing in an in vitro cell line model

OBJECTIVE

The purpose of this study was to investigate dexamethasone redosing as function of time and dose.

STUDY DESIGN

We studied the effect of 48 hours' exposure to various concentrations of dexamethasone in a human pulmonary adenocarcinoma cell line (H-441). We measured the level of surfactant protein B (SP-B) mRNA by quantitative reverse transcription-PCR after initial dexamethasone exposure, and after redosing, 1 or 2 weeks later. Values are mean +/- SE for 5 experiments. Comparisons were made by Mann-Whitney and Kruskal-Wallis test with significance set at P < .05.

RESULTS

Induction of SP-B mRNA was maximal within 48 hours of the initial dexamethasone exposure. Redosing with the same dexamethasone concentration resulted in levels more than double those initially observed. Redosing with dexamethasone concentration 10 times lower had an effect comparable to that of the initial, higher concentration.

CONCLUSION

Our results suggest a residual effect of the initial exposure that potentiates redosing, allowing significant dose reductions.

Tetanus in pregnancy

Tetanus remains a leading cause of maternal and neonatal morbidity and mortality in developing countries. It is caused by the release of two toxins produced by Clostridium tetani, a noninvasive gram-positive anaerobic bacillus. Tetanospasmin is taken up by the neuronal end plates and prevents neurotransmitter release at the synaptic junction. This leads to spasms and is irreversible. Recovery requires the formation of new neurons and may take months. Generalized muscle spasm, respiratory compromise, and autonomic dysfunction are all common clinical manifestations. Diagnosis is based mainly on history and clinical examination. The management of the pregnant woman is similar to the nonpregnant individual. The main objectives are prompt prevention of further toxin absorption, wound debridement, antibiotic therapy, and aggressive supportive care. Primary and secondary prevention protocols are important worldwide because tetanus is a preventable disease. The tetanus toxoid vaccine can be given in pregnancy.

The effects of dexamethasone and betamethasone on surfactant protein-B messenger RNA expression in human type II pneumocytes and human lung adenocarcinoma cells

OBJECTIVE

The purpose of this study was to compare the effect of a single 48-hour exposure to betamethasone or dexamethasone in the NCI-H441 cell line and in human type II pneumocytes.

STUDY DESIGN

NCI-H441 cells were exposed 48 hours to varying concentrations of betamethasone or dexamethasone (10(-10) to 10(-7) mol/L) alone or in combination with 1 mmol/L dibutyryl cyclic adenosine monophosphate. Likewise, human type II pneumocytes were exposed 48 hours to varying concentrations of betamethasone or dexamethasone (10(-9) to 10(-7) mol/L) alone or in combination with 1 mmol/L dibutyryl cyclic adenosine monophosphate. The measured outcome was the stimulatory effect on surfactant protein B gene transcription as expressed by surfactant protein B messenger RNA accumulation. The experiment was conducted 5 times in NCI-H441 cells and 6 times in type II cells, in parallel with control. Surfactant protein B messenger RNA was determined at control level and 48 hours after exposure by quantitative reverse transcription-polymerase chain reaction.

RESULTS

A similar dose-dependent response in surfactant protein B messenger RNA expression was seen with both betamethasone and dexamethasone. In human type II pneumocytes, the inductive profile of surfactant protein B messenger RNA after 48-hour exposure to betamethasone or dexamethasone was similar to that seen in the NCI-H441 cells.

CONCLUSION

Dexamethasone and betamethasone achieved similar dose-response patterns of surfactant protein-B expression in vitro.

A randomized, placebo-controlled trial of corticosteroids for hyperemesis due to pregnancy

OBJECTIVE

Hyperemesis gravidarum, a severe form of nausea and vomiting due to pregnancy for which there is no proven pharmacological treatment, is the third leading cause for hospitalization during pregnancy. Corticosteroids are commonly used for the treatment of nausea and vomiting due to cancer chemotherapy-induced emesis and might prove useful in hyperemesis gravidarum.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted in 126 women who previously had not responded to outpatient therapy for hyperemesis gravidarum during the first half of pregnancy. Intravenous methylprednisolone (125 mg) was followed by an oral prednisone taper (40 mg for 1 day, 20 mg for 3 days, 10 mg for 3 days, 5 mg for 7 days) versus an identical-appearing placebo regimen. All women also received promethazine 25 mg and metoclopramide 10 mg intravenously every 6 hours for 24 hours, followed by the same regimen administered orally as needed until discharge. The primary study outcome was the number of women requiring rehospitalization for hyperemesis gravidarum.

RESULTS

A total of 110 women delivered at our hospital and had pregnancy outcomes available for analysis; 56 were randomized to corticosteroids and 54 were administered placebo. Nineteen women in each study group required rehospitalization (34% versus 35%, P =.89, for corticosteroids versus placebo, respectively).

CONCLUSION

The addition of parenteral and oral corticosteroids to the treatment of women with hyperemesis gravidarum did not reduce the need for rehospitalization later in pregnancy.

Gestational Diabetes:

Many clinicians in the United States routinely screen all pregnant women in their practices for gestational diabetes. Recently, the US Preventive Services Task Force re-emphasized that such screening is not supported by rigorous scientific evidence. Recommendations for diagnosis and management are based on an even scantier scientific foundation. Although this review questions several aspects of current dogma, it, too, is based on the frequently flawed existing data. It is surprising how, in spite of an abundance of published information on the subject, we continue to be ignorant of the real benefits of the widespread practice of screening and treating for gestational diabetes. The authors hope that the results of a randomized clinical trial, now in progress, will help to resolve some of the controversies surrounding gestational diabetes.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to describe the controversy surrounding the significance of gestational diabetes, to break down the data regarding the efficacy of screening for gestational diabetes, and to outline potential treatment options for gestational diabetes.

Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

BACKGROUND

Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery.

METHODS

We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle.

RESULTS

Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36.3 percent in the progesterone group vs. 54.9 percent in the placebo group; relative risk, 0.66 [95 percent confidence interval, 0.54 to 0.81]), delivery at less than 35 weeks of gestation (incidence, 20.6 percent vs. 30.7 percent; relative risk, 0.67 [95 percent confidence interval, 0.48 to 0.93]), and delivery at less than 32 weeks of gestation (11.4 percent vs. 19.6 percent; relative risk, 0.58 [95 percent confidence interval, 0.37 to 0.91]). Infants of women treated with 17P had significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen.

CONCLUSIONS

Weekly injections of 17P resulted in a substantial reduction in the rate of recurrent preterm delivery among women who were at particularly high risk for preterm delivery and reduced the likelihood of several complications in their infants.

Mirror syndrome. A case report

BACKGROUND

Water retention in a pregnant woman can mirror fetal hydropic changes. This clinical presentation has been named "mirror syndrome." Awareness of the syndrome is important due to the associated fetal and maternal risks.

CASE

A 26-year-old woman, gravida 3, para 1011, presented at 31 weeks' gestation with significant edema and a 7-km weight gain in one week. Sonographic evaluation revealed hydramnios and fetal ascites. Maternal workup was negative for preeclampsia, diabetes, or cardiac or renal dysfunction. A workup for nonimmune hydrops was also negative. Over the next three days there was progression of maternal edema. With diagnosis of mirror syndrome, the decision for delivery was made. Both neonate and mother subsequently did well, with normalization of ascites and edema, respectively.

CONCLUSION

Our case, along with 19 reviewed in the literature, reiterate the features of mirror syndrome and provide an opportunity to dispel some of the misconceptions in the literature. The condition is frequently mistaken for preeclampsia, although distinguishing characteristics can be identified. Mirror syndrome is a manifestation of extremely severe fetal hydrops. When the specific cause of fetal hydrops cannot be identified and corrected, immediate delivery is necessary in order to avoid fetal death and maternal complications.

Antenatal corticosteroids in women with preterm premature rupture of the membranes

The authors believe that the literature provides sufficient evidence that antenatal corticosteroid administration is beneficial and safe even in conditions of ruptured membranes. The evidence by now is remarkably robust and one can be reasonably confident regarding the benefits of antenatal corticosteroids in the setting of ruptured membranes. As recently stated by a group of investigators from New Zealand, including Liggins, the originator of this historical medical intervention (antepartum corticosteroids), the safety and efficacy of corticosteroids in conditions of ruptured membranes is beyond any doubt. It is time to accept this reality and to move on to other unresolved issues, like the optimal dose and corticosteroid preparation, the optimal timing of treatment, or the optimal exposure interval.