The obstetrician's role in reducing the risk of aspiration pneumonitis: With particular reference to the use of oral antacids

Aspiration of gastric contents is the commonest cause of maternal anesthetic death. If the pH of the contents is below 2.5, morbidity and mortality rates are likely to be higher than if the pH is above 2.5. A study of 146 patients in labor shows that one in four patients is “at risk” to acid aspiration. No time interval between last meal and either onset of labor or delivery can guarantee an empty stomach. The use of oral antacids during labor reduces the number at risk to 1 in 35. Other methods by which the obstetrician may contribute to reducing the risk are discussed.     

A review of premature birth and subclinical infection.

Premature birth causes high rates of neonatal morbidity and mortality. There are multiple causes of preterm birth. This article reviews the evidence linking subclinical infection and premature birth. Although maternal genital tract colonization with specific organisms has been inconsistently associated with preterm birth and/or premature rupture of membranes, some infections have been consistently associated with preterm delivery. The association of histologic chorioamnionitis with prematurity is a consistent finding, but the mechanisms require further study. The relationship between histologic chorioamnionitis infection and the chorioamnionitis of prematurity requires additional research. A varying number of patients in "idiopathic" preterm labor have positive amniotic fluid cultures (0% to 30%), but it is not clear whether infection preceded labor or occurred as a result of labor. Evidence of subclinical infection as a cause of preterm labor is raised by finding elevated maternal serum C-reactive protein and abnormal amniotic fluid organic acid levels in some patients in preterm labor. Biochemical mechanisms for preterm labor in the setting of infection are suggested by both in vitro and in vivo studies of prostaglandins and their metabolites, endotoxin and cytokines. Some, but by no means all, antibiotic trials conducted to date have reported decreases in prematurity. These results support the hypothesis that premature birth results in part from infection caused by genital tract bacteria. In the next few years, research efforts must be prioritized to determine the role of infection and the appropriate prevention of this cause of prematurity.     

Trial of labor in the patient with a prior cesarean birth

The increasing incidence of cesarean birth has become quite controversial. The practice of delivering virtually all women with a prior cesarean section by repeat cesarean section is open to debate. In a large institutional practice, with rapid availability of all support services, selective attempts to deliver women vaginally, after a prior cesarean section, is appealing. A prospective 1-year study on all patients with a prior cesarean delivery commenced July 1, 1982. There were 1209 patients, of whom 751 (62%) underwent a trial of labor and 614 (82%) achieved vaginal delivery. There was no maternal mortality or perinatal mortality attributed to the trial of labor process. Oxytocin usage occurred in 38% of this population. The incidence of uterine rupture and scar dehiscence was similar in the various study subgroups. The overall group of women undergoing a trial of labor had significantly fewer postpartum complications and shorter hospital stays.     

The role of antepartum testing in the management of postterm pregnancies with heavy meconium in early labor

The documented association between heavy meconium in early labor and increased perinatal morbidity and mortality has alerted physicians to the presence of a potential high-risk fetal condition and to the possible need for immediate fetal blood pH determination. The purpose of this study was to determine whether antepartum fetal assessment can predict whether a postterm fetus with heavy meconium in early labor is at low or high risk for an adverse perinatal outcome. Eight hundred thirty-nine postterm patients were followed with antepartum testing, consisting of twice-weekly fetal heart rate (FHR) testing and ultrasonic amniotic fluid volume estimation. Overall, patients with heavy meconium in early labor had a significantly greater frequency of fetal distress. However, when women with heavy meconium in early labor were separated according to their antepartum testing results, those with normal results were found to have no greater risk for fetal distress or perinatal morbidity than women with normal testing and subsequently clear amniotic fluid. These findings suggest that postterm patients with heavy meconium in early labor and normal antepartum testing can be managed in labor in the same manner as low-risk patients without meconium.     

Indications for and timing of delivery in diabetic pregnancies

The management of 430 diabetic pregnancies is presented. Our protocol emphasized "tight" metabolic control and assessment of fetal well-being by antepartum fetal heart rate testings and estriol levels. Spontaneous labor was allowed in uncomplicated Class A diabetic patients. Labor in complicated cases and insulin-dependent diabetic pregnancies was induced after establishing fetal lung maturity, except when a maternal or fetal complication dictated otherwise. A significant drop in estriol was observed in 4% of Class A diabetic patients and 10.2% of insulin-dependent diabetic patients. None developed a positive contraction stress test. Abnormal fetal well-being tests contributed minimally to the indications for induction of labor. The incidence of induced preterm delivery was 2.8% in Class A diabetic patients and 18.4% in insulin-dependent diabetic ones. The perinatal mortality was 5.6:1000 and 13:1000, respectively. The incidence of respiratory distress syndrome was very low, and none of the cases were associated with a "mature" amniotic fluid lecithin phosphorus measurement.     

Vaginal birth after cesarean section: results of a multicenter study

Cesarean section is now the most frequently performed major operation in the United States. Nearly one out of every four American babies is delivered by this operation. "Elective repeat" has become the most common indication for cesarean section. Although the safety of vaginal birth after cesarean section has been documented in several recent publications, automatic repeat cesarean section remains the rule in this country. We present one of the largest series of trial of labor ever reported. Of 57,553 live births, 4929 (8.6%) were of women with prior cesarean sections. Among 1776 patients who underwent a trial of labor, 1314 (74%) delivered vaginally. There was no maternal or perinatal mortality related to uterine scar rupture. Thus during the study period 1314 major operations were avoided. We conclude that, for the vast majority of women, allowing a trial of labor is a safe alternative to automatic elective repeat cesarean section.     

Use of the labor graph in Malawi

A facsimile of the 1-page labor chart provided by the Ministry of Health and used at all maternity clinics in Malawi is described. Malawi has 350 maternity units which take care of 45% of deliveries. Personnel range from nonprofessional to registered nurse-midwives to physicians. The most notable feature of the chart is a partogram marked with "alert" and "action" lines, for comparing cervical dilation per hour. The alert line is a diagonal line starting at 3 cm dilated and fully effaced, drawn at an angle representing the slowest 10% of normal African primigravidas. Normally vaginal delivery would be expected at the time of the end of the action line. The action line is drawn arbitrarily 4 hours to the right, allowing time for normal delivery or transfer of the patient. Fetal descent is also charted in fifths of head palpable above the pelvic brim. There is room to the left of the page to chart progress in latent phase. One side of the chart contains demographic and admission data and the progress graph. The reverse side has space for pelvic assessment, results of 2nd and 3rd stage of labor and charting of up to 6 days' postpartum stay for mother and infant. There are blanks to record whether the woman has had sleep, food or homemade medicine, and room for making referrals. In practice fetal descent is followed by abdominal palpation hourly, fetal heart rate every 30 minutes, and charted as type 1, 2, or 3. Vaginal examinations are done every 4 hours for primigravidas and every 3 in multiparas. Fetal head molding is charted as -or 1+, 2+ or 3+.     

Re-evaluation of the obstetrical risk for the older primipara

The obstetric data relating to 92 older primiparas (OP) treated as regular obstetric patients and data relating to 92 older multiparas (OM) are compared to a previous study of 98 OP, which led to the conclusion that OP should not be managed as high-risk patients during gestation. No difference was found between the two periods regarding complications of pregnancy, gestational age and birth weight, onset of labor, perinatal morbidity and mortality. Nevertheless, cesarean deliveries were significantly higher in the study group. It seems that the conservative attitude towards OP during pregnancy is justified, but at labor, more rigid indications for cesarean section should be applied to establish objective patient care.     

Trial of labor in previous cesarean section patients, excluding classical cesarean sections

The American College of Obstetricians and Gynecologists has supported the concept of a trial of labor in patients with a previous lower uterine transverse cesarean section, and its safety is generally accepted. The purpose of this report was to present the results of a year-long, prospective study in which the indications for trial of labor were liberalized. Only patients with a previous classical incision or "T" incision on the uterus were excluded. Two hundred seventy-two patients elected to undergo a trial of labor. Vaginal delivery occurred in 216 patients (76.5%). Oxytocin was used as needed, and epidural anesthesia was used in all patients who requested it. One uterine rupture occurred in a patient with a single lower transverse scar. The results of this study suggest that a trial of labor is a safe alternative for patients with a previous single or multiple lower uterine transverse incision or a lower uterine vertical incision. In addition, the use of epidural anesthesia and oxytocin appears safe in patients undergoing a trial of labor.     

Trial of labor following cesarean section--a study of 212 patients

Data on the trial of labor of patients with a prior cesarean section are largely confined to studies in the First World. These results and methods may not apply to patients in developing countries. This trial studied the management of rural patients with a prior cesarean section, and tested exclusion criteria in use at the base hospital. Of those allowed a trial labor, 52% delivered vaginally. No maternal or fetal mortality occurred, and the outcome suggested a place for the controlled trial labor in selected patients.     

Impact of ALSO training on the management of prolonged labor and neonatal care at Kagera Regional Hospital, Tanzania

Objective

To evaluate the management of prolonged labor and neonatal care before and after Advanced Life Support in Obstetrics (ALSO) training.

Methods

Staff involved in childbirth at Kagera Regional Hospital, Tanzania, attended a 2-day ALSO provider course. In this prospective intervention study conducted between July and November 2008, the management and outcomes of 558 deliveries before and 550 after the training were observed.

Results

There was no significant difference in the rate of cesarean deliveries owing to prolonged labor, and vacuum delivery was not practiced after the intervention. During prolonged labor, action was delayed for more than 3 hours in half of the cases. The stillbirth rate, Apgar scores, and frequency of neonatal resuscitation did not change significantly. After the intervention, there was a significant increase in newborns given to their mothers within 10 minutes, from 5.6% to 71.5% (RR 12.71; 95% CI, 9.04-17.88). There was a significant decrease from 6 to 0 neonatal deaths before discharge among those born with an Apgar score after 1 minute of 4 or more (P = 0.03).

Conclusion

ALSO training had no effect on the management of prolonged labor. Early contact between newborn and mother was more frequently practiced after ALSO training and the immediate neonatal mortality decreased.     

Second stage disorders in patients following a previous cesarean section: vacuum versus repeated cesarean section

Objective

To investigate whether vacuum extraction due to failure of labor to progress (dystocia) during the second stage in a delivery following a previous cesarean section (CS) is related to increased adverse maternal and perinatal outcomes as compared with repeated CS.

Study design

A retrospective cohort study of pregnancy and delivery outcomes of patients in their second deliveries attempting a vaginal birth after cesarean (VBAC) following one CS was conducted. Patients who delivered by vacuum extraction were compared with patients who underwent a repeated CS for failure of labor to progress during the second stage.

Results

During the study period, 319 patients with a previous CS suffered from a prolonged second stage of labor in their second delivery. Of these, 184 underwent vacuum extraction and 135 patients underwent a repeated CS. No significant differences in relevant pregnancy complications such as perineal lacerations, uterine rupture, and post-partum hemorrhage and perinatal outcomes were noted between the groups. There were no cases of perinatal mortality in our study.

Conclusion

When managing second stage labor disorders, vacuum extraction does not seem to be an unsafe procedure in patients with a previous CS.     

Trial of labor without oxytocin in patients with a previous cesarean section

In a 30-month period, 261 of 557 (46.8%) patients underwent a trial of labor. Of these, 215 patients (82.4%) achieved vaginal delivery. The major controversial issues regarding vaginal delivery in patients with a prior cesarean section are oxytocin administration, the inclusion of patients with recurring indications, and the use of epidural analgesia. Oxytocin was not used in this study. When our results were compared to those of others who used oxytocin liberally we found that oxytocin augmentation was not a major factor in increasing significantly the success and vaginal delivery rate. We believe that oxytocin usage should be reserved for selected patients with well-defined indications. When the primary cesarean section was for cephalopelvic disproportion, 66.6% delivered vaginally. This success rate justifies the inclusion of these patients in a trial of labor. Epidural analgesia proved to be a safe and efficient procedure. There was no maternal or perinatal mortality related to trial of labor.     

The cervical balloon method for induction of labor

The cervical balloon (Embrey & Mollison) was used to induce labor in a study group of 87 patients. The control group included 97 patients, where induction of labor was performed using oxytocin-drip. In the study group oxytocin-drip was added in 34 patients. The cases of the study and control groups were classified as "favorable" cervix. The patients classified as "unfavorable" cervix showed a shorter mean induction-delivery interval in the study group, and a shorter mean duration of oxytocin-drip in the cases of the study group where it was needed. It was concluded that the cervical balloon is a convenient method for the induction of labor, for its effectivity, simplicity and innocuity, especially in the "unfavorable" cervix cases.     

Cases with ruptured membranes that "reseal"

Among patients with a diagnosis of preterm prepartal rupture of the membranes, an occasional case ceases to leak amniotic fluid before the onset of labor. The purpose of this case-control study was to determine the characteristics and obstetric outcomes of this unique group of patients. This diagnosis was made in 24 such patients who gave birth in 1984 and 1985 at Shands Hospital. Compared with matched control subjects who continued to leak fluid, there were no significant differences in maternal race, age, marital status, socioeconomic status, smoking status, or past obstetric performance. Amniotic fluid volumes, as assessed by ultrasound studies, were less in the group that failed to "reseal." The "reseal" group had longer durations of pregnancy, larger babies, longer maternal hospitalization, less neonatal hospitalization, and less perinatal mortality and morbidity. The occurrence of "resealing" appears to bode well for the mother and infant. Such cases should be sought aggressively but managed conservatively.     

Evaluation of cesarean rate: a necessary progress in modern obstetrics

During the last 10 Years, the cesarean section (CS) rate was increased despite of the recommendations of the World Health Organization to keep it below 10-15%. The purpose of this review of the literature was to demonstrate how the concept of CS rate limitation has become obsolete. The increase in the CS rate is mainly justified by the decrease in maternal mortality and morbidity following elective CS: surgery-related risks have decreased and the confusion that was made between the risks of vaginal delivery and those of trial of labor has to be clarified to show that maternal mortality and morbidity are not increased by elective CS. However, instrumental delivery and CS during labor remain two situations at high risks both for the mother and her fetus. There is also an association between the increase in the CS rate and the decrease in perinatal mortality and morbidity, but this effect would only become clinically significant after a dramatic increase in the CS rate: this is the preventile principle of "marginal death". Numerous articles have been published reporting on the effects of vaginal delivery for the pelvic floor: urinary incontinence, pelvic organ prolapse, and especially fecal incontinence. All these publications concluded that CS has a protective effect. The rising duty to provide information to patients in high risk obstetrical situations such as a history of CS also contributes to the overall increase in CS rate mainly through the elective CS rate. Indeed, when faced with the alternative choices of potentially severe complications either for themselves or their child, women are likely to choose what appears to be the safest mode of delivery for their child and thus to opt for a CS. Finally, widespread delivery of information to the patients about trial of labor itself and the risks of vaginal delivery is the first step towards a "principle of preference", which consists in giving an important place to the patient's choice in the decision-making process, and thus to recognize her right to ask for an elective CS.     

Mechanism of parturition and preterm labor

Preterm birth occurs in 5 to 10 percent of all pregnancies and accounts for 75 percent of neonatal mortality and morbidity, including long-term handicap. Thirty percent of preterm birth may be associated with an underlying infective process, and approximately 50 percent are idiopathic. Preterm birth corresponds to a syndrome with a variety of causes. The factors contributing to preterm birth may vary at different "windows" of gestation. Glucocorticoids seem to have a central role in processes of birth at term and preterm, and alter synthesis and/or activity of key enzymes in prostaglandin synthesis and metabolism as well as increasing corticotropin-releasing hormone output by intrauterine tissues. This new information should facilitate development of improved methods of diagnosis and therapy for patients at risk of preterm labor. TARGET AUDIENCE: Gynecologists and Family Physicians LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe potential mechanisms of partition and preterm labor and to list the various substances that can inhibit and promote myometrial contractions.     

Spontaneous rupture of utero-ovarian vessels in postpartal period: a case report and review of the literature

Spontaneous rupture of utero-ovarian veins occurring during pregnancy or the peripartal period is generally considered to be a medical curiosity (approximately 100 reported cases) rarely mentioned in obstetric textbooks. It is nevertheless a dramatic cause of maternal and /or fetal mortality. The available statistics are the following: 60% of the cases are directly related to labor and 50% occur in primiparas; when the rupture is associated with labor, mortality is 40%. Occurring outside of labor, mortality rate is approximatively 10%. The perinatal mortality remains high at 30%; in 75% of the cases, the broad ligament is the site of rupture (in many cases, the site of rupture is not found, at laparotomy or autopsy). We report the case of a patient who developed ovarian vein rupture on the 3rd postpartum day.