A multicenter controlled trial of fetal pulse oximetry in the intrapartum management of nonreassuring fetal heart rate patterns.

OBJECTIVE: Recent developments permit the use of pulse oximetry to evaluate fetal oxygenation in labor. We tested the hypothesis that the addition of fetal pulse oximetry in the evaluation of abnormal fetal heart rate patterns in labor improves the accuracy of fetal assessment and allows safe reduction of cesarean deliveries performed because of nonreassuring fetal status. STUDY DESIGN: A randomized, controlled trial was conducted concurrently in 9 centers. The patients had term pregnancies and were in active labor when abnormal fetal heart rate patterns developed. The patients were randomized to electronic fetal heart rate monitoring alone (control group) or to the combination of electronic fetal monitoring and continuous fetal pulse oximetry (study group). The primary outcome was a reduction in cesarean deliveries for nonreassuring fetal status as a measure of improved accuracy of assessment of fetal oxygenation. RESULTS: A total of 1010 patients were randomized, 502 to the control group and 508 to the study group. There was a reduction of >50% in the number of cesarean deliveries performed because of nonreassuring fetal status in the study group (study, 4. 5%; vs. control, 10.2%; P =.007). However, there was no net difference in overall cesarean delivery rates (study, n = 147 [29%]; vs. control, 130 [26%]; P = .49) because of an increase in cesarean deliveries performed because of dystocia in the study group. In a blinded partogram analysis 89% of the study patients and 91% of the control patients who had a cesarean delivery because of dystocia met defined criteria for actual dystocia. There was no difference between the 2 groups in adverse maternal or neonatal outcomes. In terms of the operative intervention for nonreassuring fetal status, there was an improvement in both the sensitivity and the specificity for the study group compared with the control group for the end points of metabolic acidosis and need for resuscitation. CONCLUSION: The study confirmed its primary hypothesis of a safe reduction in cesarean deliveries performed because of nonreassuring fetal status. However, the addition of fetal pulse oximetry did not result in an overall reduction in cesarean deliveries. The increase in cesarean deliveries because of dystocia in the study group did appear to result from a well-documented arrest of labor. Fetal pulse oximetry improved the obstetrician's ability to more appropriately intervene by cesarean or operative vaginal delivery for fetuses who were actually depressed and acidotic. The unexpected increase in operative delivery for dystocia in the study group is of concern and remains to be explained.

In utero repair of myelomeningocele: a comparison of endoscopy and hysterotomy.

OBJECTIVE: To compare endoscopic coverage of myelomeningocele with a maternal split-thickness skin graft in utero to definitive neurosurgical closure through a hysterotomy. METHODS: Four fetuses with isolated myelomeningocele underwent endoscopic coverage of the defect with a maternal split-thickness skin graft in a CO(2) environment at 22-24 weeks' gestation. Subsequently, 4 fetuses underwent standard neurosurgical closure of their myelomeningoceles at 28-29 weeks' gestation. RESULTS: The mean operating time for the endoscopic procedures was 297 +/- 69 min. Two fetal losses occurred as a result of chorioamnionitis and placental abruption, respectively. A third baby delivered at 28 weeks' gestation after prolonged disruption of the membranes. The 2 survivors required standard closure of the myelomeningocele after delivery. The mean operating time for the hysterotomy procedures was 125 +/- 8 min. No mortality occurred, and all the infants delivered between 33 and 36 weeks with well-healed myelomeningocele scars. At present, the functional levels of all infants approximate the anatomical levels of the lesions. CONCLUSION: With current technology, in utero repair of congenital myelomeningocele through a hysterotomy appears to be technically superior to procedures performed endoscopically.

Electronic fetal heart rate monitoring: early neonatal outcomes associated with normal rate, fetal stress, and fetal distress.

OBJECTIVE: The purpose of this study was to test the ability of a clearly defined classification system for electronic fetal heart rate monitoring to predict early neonatal outcome. STUDY DESIGN: All labors of women with singleton pregnancies > or = 32 weeks' gestation electronically monitored at 2 institutions were examined. Tracings in the final hour before delivery were defined as normal, fetal stress, or fetal distress. After delivery, Apgar scores, cord blood gas values, and admission to the neonatal intensive care unit were examined as measures of early neonatal outcome. RESULTS: Among the 898 patients who qualified for study, 627 (70%) had tracings classified as normal, 263 (29%) had tracings classified as fetal stress, and 8 (1%) had tracings classified as fetal distress. There was a significant worsening of neonatal outcome across these 3 groups with regard to depressed Apgar scores 1 minute (5.1%, 18.3%, and 75.0%; P <.05), depressed Apgar scores at 5 minutes (1.0%, 3.8%, and 37.5%; P <.05), and admission to the neonatal intensive care unit (5.6%, 10.6%, and 37.5%; P <.05). There was also a progressive worsening of cord blood pH (7.27 +/- 0.06, 7.21 +/- 0.08, and 7.06 +/- 0.14; P <.05), a progressive increase in PCO (2) (53.39 +/- 8.34 mm Hg, 58.51 +/- 10.55 mm Hg, and 78.31 +/- 20.35 mm Hg; P <.05), and a progressive decline in base excess (-3.18 +/- 2.02 mEq/L, -5. 11 +/- 3.11 mEq/L, and -9.07 +/- 4.59 mEq/L; P <.05). CONCLUSION: This simple classification system for interpreting fetal heart rate tracings accurately predicts normal outcomes for fetuses as well discriminating fetuses in true distress. Further, it identifies an intermediate group of fetuses with a condition labeled fetal stress who might benefit from additional evaluation and possibly from expeditious delivery.

Intrapartum fetal heart rate monitoring.

Intrapartum fetal heart rate monitoring is commonly used to evaluate fetal status in labor, despite a lack of convincing randomized studies to support its use. The National Institutes of Health have helped standardize fetal heart rate monitoring terminology with their 1997 task force report, which will aid clinicians and scientists in their goal of providing quality care and research. The American College of Obstetricians and Gynecologists has recommended the term nonreassuring fetal status for electronic fetal monitor patterns that are not normal; however, Vanderbilt continues to use the terms fetal stress and fetal distress, using specific criteria for each. The approximately 30% of fetal heart rate tracings labeled as fetal stress (or nonreassuring fetal status) can be evaluated further by the use of fetal pulse oximetry, a new technology currently under evaluation in this country.

The Tulipan-Bruner trocar for uterine entry during fetal surgery.

OBJECTIVE: Our goal was to compare the use of a specially designed trocar for initial uterine entry with standard entry by electrocautery in creation of a hysterotomy for fetal surgery. STUDY DESIGN: Ten consecutive patients undergoing hysterotomy for intrauterine repair of myelomeningocele were randomized to initial uterine entry with electrocautery or with the Tulipan-Bruner trocar. Timing of initial uterine entry with electrocautery began with incision into the uterine serosa and ended with incision of the chorioamnionic membranes. Timing of initial uterine entry with the Tulipan-Bruner trocar began with placement of stay sutures and ended with removal of the central introducer from the peel-away sheath. Blood loss was estimated by the primary surgeon. All of the participating surgeons judged the convenience and ease of each technique. The times required for initial uterine entry were compared with an unpaired t test. Statistical significance was set at P <.05. RESULTS: The time required for initial uterine entry with electrocautery was 231 +/- 63 (mean +/- SD) seconds compared with 146 +/- 51 seconds with the trocar (P <.05). The total blood loss for all 10 cases was <50 mL, but the presence of blood in the wound was judged much more inconvenient when electrocautery was used. Finally, electrocautery required 2 surgical assistants in every case, whereas the trocar was readily placed with only a single assistant. CONCLUSION: The Tulipan-Bruner trocar provides quicker, less traumatic uterine entry during creation of a hysterotomy, as compared with electrocautery.

Fetal surgery for myelomeningocele and the incidence of shunt-dependent hydrocephalus.

CONTEXT: Intrauterine closure of exposed spinal cord tissue prevents secondary neurologic injury in animals with a surgically created spinal defect; however, whether in utero repair of myelomeningocele improves neurologic outcome in infants with spina bifida is not known. OBJECTIVE: To determine whether intrauterine repair of myelomeningocele improves patient outcomes compared with standard care. DESIGN: Single-institution, nonrandomized observational study conducted between January 1990 and February 1999. SETTING: Tertiary care medical center. PARTICIPANTS: A sample of 29 study patients with isolated fetal myelomeningocele referred for intrauterine repair that was performed between 24 and 30 gestational weeks and 23 controls matched to cases for diagnosis, level of lesion, practice parameters, and calendar time. All infants were followed up for a minimum of 6 months after delivery. MAIN OUTCOME MEASURES: Requirement for ventriculoperitoneal shunt placement, obstetrical complications, gestational age at delivery, and birth weight for study vs control subjects. RESULTS: The requirement for ventriculoperitoneal shunt placement for decompression of hydrocephalus was significantly decreased among study infants (59% vs 91%; P = .01). The median age at shunt placement was also older among study infants (50 vs 5 days; P = .006). This may be explained by the reduced incidence of hindbrain herniation among study infants (38% vs 95%; P<.001). Following hysterotomy, study patients had an increased risk of oligohydramnios (48% vs 4%; P = .001) and admission to the hospital for preterm uterine contractions (50% vs 9%; P = .002). The estimated gestational age at delivery was earlier for study patients (33.2 vs 37.0 weeks; P<.001), and the birth weight of study neonates was less (2171 vs 3075 g; P<.001). CONCLUSIONS: Our study suggests that intrauterine repair of myelomeningocele decreases the incidence of hindbrain herniation and shunt-dependent hydrocephalus in infants with spina bifida, but increases the incidence of premature delivery.

The clinical significance of intermittent sinusoidal fetal heart rate.

Sinusoidal fetal heart rate may have a spectrum of occurrence that indicates degree of fetal morbidity. Twelve cases of intermittent sinusoidal fetal heart rate were reviewed for fetal outcome. Findings of anemia, low umbilical cord pH, and large base excess support that intermittent sinusoidal fetal heart rate may be an early indicator of impending fetal compromise.

Prevention of preterm birth. Role of daily telephone contact.

OBJECTIVE: To compare the effectiveness of routine management of patients at high risk for preterm delivery to the effectiveness of routine management in combination with daily telephone nursing contact. STUDY DESIGN: The control group, 1 (n = 21), had education and frequent prenatal visits and cervical examinations. The study group, 2 (n = 21), had education, frequent prenatal visits and cervical examination, and daily telephone contact. Group 3 (n = 22) received education but refused to participate. RESULTS: There were no significant differences (SD) between groups in race, smoking, age, multiple gestation, visits, diagnosis of premature labor, mean days gained after diagnosis of premature labor, tocolytic use or bed rest. There was also no SD in preterm birth rate, mode of delivery, number of maternal or neonatal hospital days, mean neonatal weight or gestational age at delivery between groups. While not reducing the overall incidence of preterm birth, this management for all groups resulted in a more advanced gestational age at the time of delivery (mean change = 7.5 weeks, P < .0001) when compared to the patient's first preterm birth. CONCLUSION: This study indicated that daily contact, while providing reassurance and support, did not change the outcome when the study group was compared to women managed similarly but without daily contact.

Placenta previa increta diagnosed at 18 weeks' gestation. Report of a case with sonographic and pathologic correlation.

BACKGROUND: Placenta previa incerta, although uncommon, assumes considerable clinical significance because of the morbidity associated with severe hemorrhage, uterine perforation and infection. The majority of cases are unanticipated and initially identified intraoperatively. CASE: Placenta accreta was diagnosed sonographically at 18 weeks' gestation in a multipara who had previously undergone cesarean delivery. Additionally, the gestation was complicated by chronic renal failure secondary to systemic lupus erythematosus. After appropriate counseling, total abdominal hysterectomy was performed prior to fetal viability. CONCLUSION: Early sonographic evaluation of the placenta is recommended for those at significant risk of invasive placentation. Timely detection facilitates proper preparation and should reduce maternal morbidity.

Emergency management of fetal stress and distress in the obstetric patient.

The clinical use of intrapartum fetal heart rate monitoring remains controversial. Because of its widespread use in this country, interpretation skills must be maintained. Clear and concise criteria for the diagnosis of fetal stress and distress are presented in this article, and the management of fetal distress is discussed.

The umbilical artery Doppler ultrasonographic gradient: confirmation, cause, and comparison of continuous-wave and duplex ultrasonographic pulsed-wave measurements.

The umbilical artery Doppler ultrasonographic gradient has been described, and the need for site-specific nomograms has been pointed out. However, controversy still exists about the cause of this phenomenon and the optimal site for obtaining umbilical artery Doppler ultrasonographic measurements. Cross-sectional measurements of umbilical artery flow velocity waveform (FVW) systolic/diastolic (S/D) ratios were therefore made in 35 gravid women during the second or third trimester of pregnancy with both duplex pulsed-wave (PW) and free-standing continuous-wave (CW) Doppler ultrasonographic equipment. Multiple duplex PW Doppler ultrasonographic signals were recorded at the abdominal cord insertion, placental cord insertion, and free cord sites. Multiple CW Doppler FVWs were obtained from four quadrants, in decreasing order of ease of measurement. Repeated-measures analysis of variance demonstrated a statistically significant decrease in mean and median values of the umbilical artery S/D ratio from the abdominal cord insertion site to the placental cord insertion site. The reduction in the value of the S/D ratio as the placental cord insertion site is approached results more from a decrease in the peak systolic maximum velocity envelope than from an increase in diastolic velocities. Moreover, mean and median CW Doppler ultrasonographic values correlate most closely with corresponding PW measurements of the free cord segment. These data confirm the presence of the umbilical artery Doppler ultrasonographic gradient. Decreasing values of the S/D ratio from the fetal abdomen to the placenta are a result of attenuation of the systolic maximum velocity envelope.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenytoin protects against hypoxia-induced death of cultured hippocampal neurons.

The neuroprotective actions of the anticonvulsant phenytoin (diphenylhydantoin, PHT) were evaluated using 3 week old primary hippocampal cultures derived from 19 day embryonic rat. When added to the culture medium prior to a hypoxic insult, PHT increased neuronal viability two-fold. Doubling extracellular Mg2+ concentration was similarly neuroprotective. In contrast, PHT was unable to protect against hypoxia-induced death in one week old cultures, nor was PHT protective against N-methyl-D-aspartate (NMDA)-induced neurotoxicity in cultures of either age. These findings suggest that non-NMDA receptor mechanisms are important in hypoxia-induced neuronal death, and may have important implications for the treatment of stroke.

Chorionic villus sampling: quality control--a continuous improvement model.

OBJECTIVE: Our purpose was to describe Vanderbilt University Medical Center's experience in establishing a chorionic villus sampling program and the importance of quality control along with a continuous improvement model on the first 1000 cases. STUDY DESIGN: A continuous improvement model was established with emphasis on a multidisciplinary team approach and quality assurance process. A computerized data base was used for continuing analysis of complications and for allowing facile access to pertinent information. RESULTS: A continuous improvement model allowed for an improved process and outcome for patients, personnel, and referring health care providers. Follow-up for initial symptoms after chorionic villus sampling was obtained on 98.5% of patients. Pregnancy follow-up, including birth data, was obtained on 93%. CONCLUSION: A continuous improvement mode from the project's onset resulted in an improved process and outcome, information helpful for accessing spontaneous abortion rates and pregnancy outcomes (including the incidence of limb abnormalities and factors associated with abortions) and recommendations for training personnel.

Transcallosal, transventricular approach to a basilar apex aneurysm.

A new approach to the basilar apex in a patient with a megadolichobasilar anomaly and an abnormally rostral basilar apex aneurysm is described. The details of the surgical approach and the advantages and limitations of this transcallosal, interseptal approach are described.

Preterm premature rupture of membranes: detection of infection.

This prospective study was designed to determine the value of a daily modified biophysical profile in detecting infection in patients with preterm premature rupture of the membranes who were managed expectantly. Ninety-nine patients received daily nonstress tests and biophysical profile scores. Results of the last predelivery study were related to subsequent development of amnionitis or fetal sepsis. Infection was present in 16 patients. When the biophysical profile score was 0/8, infection was uniformly present. When fetal breathing was absent (biophysical profile score, less than or equal to 4/8) and nonstress test was nonreactive, infection was present in 75% of cases (sensitivity, 75%; specificity, 95%). Because a nonreactive nonstress test could be secondary to prematurity instead of infection, these results were analyzed over time. Those who initially had a reactive nonstress test that subsequently became nonreactive were more likely to be infected. We conclude that a daily biophysical profile score and nonstress test can detect infection and propose delivery of patients with a biophysical profile score of 0/8 and nonreactive nonstress test. Patients with absent fetal breathing and a nonstress test that changes from reactive to nonreactive also should be considered for delivery. Absent fetal breathing with a reactive nonstress test or a consistently nonreactive nonstress test should have further testing to rule out infection.

Selective termination in multiple pregnancies: ethical considerations.

PIP: For those patients who have multiple pregnancies there are several considerations that must be made. When the pregnancies are the result of induced ovulation there is a significant iatrogenic element. Counselling must be provided for couples throughout the entire process. From the beginning of the inductio n program emphasis on the risks associated with multiple gestations must be clearly explained. Such events increase the risk of fetal anomalies, premature births, and poorer outcomes. The alternatives, including selective reduction must be discussed because of these risks. Also, while the patient may recognize the risks of such therapy, it is critical that they be provided with numerous chances to reassess their decision. Thus, informed consent is much broader than merely signing a form. It must be an on going process in which the patient is given any chance necessary to modify the therapy. Further, selective reduction, if it is chosen as an option, must be performed by caring and competent health professionals who are fully cognizant of the ethical and moral issues that are involved with the procedure. It is essential that physicians recognize the fact that abortion is not always something that women plan deliberately or necessarily regard as morally correct. Often times it is viewed as a necessary intervention resorted to only if the alternatives would be worse than the act itself.^ieng

Cordocentesis for rapid karyotyping.

Pure fetal blood was obtained by cordocentesis in 101 fetuses of 96 patients at 15 to 38 weeks' gestation. Rapid karyotype was obtained within 2 to 4 days by fetal lymphocyte culture. Chromosomal abnormality was detected in 12 (11.9%) fetuses. Abnormal karyotype was found in 5 of 44 fetuses with structural malformations, 3 of 13 fetuses with intrauterine growth retardation or oligohydramnios, 1 of 3 fetuses with nonimmune hydrops fetalis, 2 (one monozygotic set) of 10 discordant twins, 1 of 12 isoimmunized gestations, none of 8 cases with advanced gestational-maternal age, and none of 6 immune thrombocytopenia cases. This suggests that rapid karyotype should be obtained in all cases of fetal structural malformations, intrauterine growth retardation, and nonimmune fetal hydrops, and may be obtained incidentally in isoimmunized pregnancies and discordant twins to assist in clinical management.