Barry S. Schifrin

Antepartum fetal heart rate testing: I. Evolution of the nonstress test

On May 1, 1975, at Womens Hospital, Los Angeles County--University of Southern California Medical Center, a new antepartum fetal heart rate (AFHRT) protocol was put into clinical use. This included the widely used contraction stress test (CST) and a new concept of nonstress testing (NST). The NST was based on FHR response associated with fetal movements and was categorized as reactive (normal) or nonreactive (abnormal). The nonreactive fetus was then evaluated with a CST if not contraindicated. During the 24 months, May 1, 1975 to April 30, 1977, a total of 2,422 NSTs were done in 1,169 patients with 1,547 (64 per cent) reactive and 829 (35 per cent) nonreactive. CST was done 939 times, with 851 (90.6 per cent) negative, 29 (3 per cent) positive, 13 (1.4 per cent) equivocal, and 46 (5.0 per cent) unsatisfactory. There were ten (3.3 per cent) perinatal deaths within one week of a negative CST, five (1.0 per cent) within one week of a reactive NST, and two (8.7 per cent) with a positive CST. A reactive NST was as predictive of good outcome as was a negative CST. Analysis of the nonreactive NST showed that two or more accelerations were not associated with abnormal CSTs. Also, some nonreactive fetuses became reactive with oxytocin and had good outcome. These observations were utilized in the development of a newer, shorter NST which allows for fetal stimulation in an attempt to further define fetal well-being.

Clinical fetal monitoring. VII. The evaluation and significance of intrapartum baseline FHR variability.

The clinical usage of intrapartum fetal monitoring has increased dramatically in the past few years. Understanding of the pathophysiologic significance of FHR patterns has been further elucidated, but quantitation and prediction on an individual basis at times present a practical clinical dilemma. Baseline FHR variability was evaluated in order to see if it provided additional commentary on fetal status. The presence of FHR variability appears to be a favorable commentary regarding both fetal and newborn status. A clinical method of apprasing FHR is presented and the significance of FHR variability suggested.

Significance of meconium during labor.

Continuous fetal heart rate (FHR) monitoring and routine fetal scalp blood sampling was utilized in the evaluations of 366 fetuses during labor. One hundred and six patients had meconium in the amniotic fluid at some time during labor. A total of 26,110 uterine contractions were monitored during these 366 labors. The incidence of FHR patterns as a percentage of uterine contractions was calculated for the meconium and nonmeconium groups. Although there was a 3 1/2-fold increase in the incidence of low five-minute Apgar scores (less than 7) in the meconium group, signs of fetal distress were, with rare esception, not significantly different from those in the nonmeconium group. The presence of meconium in the amniotic fluid without signs of fetal asphyxia (late decelerations and acidosis) is not a sign of fetal distress and need not be an indication for active intervention. The combination of fetal asphyxia and meconium staining of the amniotic fluid, however, does enhance the potential for meconium aspiration and a poor neonatal outcome. Universal fetal heart rate monitoring and appropriate fetal acid-base evaluation is recommended for following patients with meconium in the amniotic fluid during labor.

Urinary tract endometriosis: Enigmas in diagnosis and management

The diagnosis and management of endometriosis presents several enigmas. This review, of eight patients with endometriosis involving the urinary tract, from three large clinical services in the City of Los Angeles, highlights some very difficult problems. Not only diagnostic errors but also inappropriate conservatism and inadequate surveillance have led to compromised function, resection, and/or destruction of the kidneys, ureters, or bladder. The series indicates those findings which are likely to result in urinary tract destruction and points out those clinical situations in which delays or conservative management must be undertaken only with pressing indications and then only with continued and careful surveillance.

Pyelonephritis in pregnancy: a prospective randomized trial to prevent recurrent disease evaluating suppressive therapy with nitrofurantoin and close surveillance

It has been advocated that if a patient develops acute pyelonephritis during pregnancy, she should receive suppressive therapy for the remainder of the gestation to prevent a recurrence of the disease. We have prospectively evaluated 200 patients following an acute episode of pyelonephritis during pregnancy. All patients were followed in a special clinic. Half the patients received nitrofurantoin as suppressive therapy. Recurrent pyelonephritis occurred in 7% of the patients receiving suppressive therapy versus 8% of those patients receiving close surveillance in the clinic. The results cast doubt upon the need for suppressive therapy and instead dramatized the beneficial effects of close surveillance with cultures. The data also suggest, at least in a high-risk population, that patients with gram-negative bacilluria of less than 10(5) colonies/ml may have a substantial risk of developing symptomatic recurrences. Prompt treatment of even low levels of gram-negative bacilluria should be considered in patients at risk for recurrent disease.

Comparison of antepartum testing schemes for the management of the postdate pregnancy

We analyzed the outcome results of 583 postdate pregnancies managed prospectively by one of three antepartum testing schemes, each predicated on the nonstress test. In scheme 1, we relied upon the contraction stress test for evaluation of the nonreactive nonstress test. In scheme 2, we used a modified biophysical profile to evaluate the nonreactive nonstress test. In addition, patients were tested semiweekly. In scheme 3, we added routine weekly ultrasound evaluation of amniotic fluid volume to scheme 2. Only in scheme 3 did we induce labor for decreased amniotic fluid volume or fetal cardiac decelerations irrespective of reactivity. The incidence of fetal distress, perinatal mortality, and perinatal morbidity was increased in babies with decelerations or decreased amniotic fluid volume. Nevertheless, outcome results in scheme 2 were improved over those with scheme 1 and were best with scheme 3. These results suggest a benefit to both semiweekly testing and liberalized criteria for intervention in postdate pregnancies. We also compared the outcome results of scheme 3 with those reported for schemes in which the weekly contraction stress test was used as the primary form of surveillance. We found the outcome results comparable in that both schemes showed minimal mortality and morbidity statistics but high intervention rates (25% to 30%). Differences in methodology and test criteria, however, make such comparisons less than ideal.

The role of real-time scanning in antenatal fetal surveillance

The additional value of real-time ultrasound scanning (RTBS) in antepartum assessment of fetal well-being was studied in 158 high-risk patients after a nonstress test (NST). Fetal breathing movements (FBM), fetal movements (FM), tonus (TON), and normal amniotic fluid volume (AFV) when present on RTBS were reliable signs of fetal well-being. These ultrasound markers of fetal well-being appeared to be as reliable indicators of good outcome as the reactive NST. Multiple indicators did not improve the accuracy of the prediction of normal outcome. All test results were normal in only about 50% of patients. In general, abnormal test results were poor indicators of poor outcome. Only when all parameters were abnormal were babies invariably affected. Five of six babies with major anomalies showed increased AFV, and seven of 13 growth-retarded or postmature babies demonstrated decreased AFV. The parameters obtained on RTBS appeared to be far more reliable than the contraction stress test (CST) in discriminating the truly abnormal fetus. Three babies with positive CST in this study had normal outcomes. These results, if confirmed in larger studies, suggest that RTBS after a nonreactive NST is an effective and potentially economical method of fetal assessment.

Accuracy and reliability of fetal heart rate monitoring using maternal abdominal surface electrodes.

Objective. Compare the accuracy and reliability of fetal heart rate identification from maternal abdominal fetal electrocardiogram signals (ECG) and Doppler ultrasound with a fetal scalp electrode. Design. Prospective open method equivalence study. Setting. Three urban teaching hospitals in the Northeast United States. Sample. 75 women with normal pregnancies in labor at >37 weeks of gestation. Methods. Three fetal heart rate detection methods were used simultaneously in 75 parturients. The fetal scalp electrode was the standard against which abdominal fetal ECG and ultrasound were judged. Main outcome measures. The positive percent agreement with the fetal scalp electrode indicated reliability. Bland–Altman analysis determined accuracy. The confusion rate indicated how frequently the devices tracked the maternal heart rate. Results. Positive percent agreement was 81.7 and 73% for the abdominal fetal ECG and ultrasound, respectively (p = 0.002). The abdominal fetal ECG had a lower root mean square error than ultrasound (5.2 vs. 10.6 bpm, p < 0.001). The confusion rate for ultrasound was 20‐fold higher than for abdominal ECG (8.9 vs. 0.4%, respectively, p < 0.001). Conclusion. Compared with the fetal scalp electrode, fetal heart rate detection using abdominal fetal ECG was more reliable and accurate than ultrasound, and abdominal fetal ECG was less likely than ultrasound to display the maternal heart rate in place of the fetal heart rate.

Acute Oligohydramnios in postdate pregnancy

The evaluation of amniotic fluid volume plays a major role in antepartum fetal surveillance. Although the definition of diminished amniotic fluid volume varies, this sign is considered by itself an indication for intervention in the near-term fetus. The interval of testing is predicated on the concept that amniotic fluid volume diminishes slowly (unquantified) as a result of developing hypoxia. We present six postterm pregnancies in which amniotic fluid volume diminished abruptly over 24 hours. Although one fetus died, the three babies delivered by cesarean section and the two babies delivered after a 2-day labor did well, despite obvious postmaturity syndrome, meconium staining, and variable decelerations. Apgar scores in the survivors were above 8, and pH results failed to confirm hypoxia. These data suggest the need to better understand the mechanisms regulating amniotic fluid volume.

The effect of malpractice claims on the use of caesarean section.

Malpractice fears are believed to influence various aspects of obstetrical practice. They seem to have contributed in small part to the rising primary caesarean section rate, but have also played a considerable role in the downtrend in vaginal birth after caesarean statistics. The rising vaginal birth after caesarean section rate between 1981 and 1995 was interrupted by a spate of lawsuits associated with broadened indications for vaginal birth after caesarean section in conjunction with requirements for immediate clinician availability. These factors dramatically reduced the availability of hospitals and clinicians willing to offer vaginal birth after caesarean section. This reversal, however, has not diminished the demand for vaginal birth after caesarean section from various stakeholders in the name of patient autonomy, clinician beneficence and optimal care. Nevertheless, as long as stringent requirements remain for clinician attendance during vaginal birth after caesarean section, and as long as the spectre of preventable error and the lingering dread of lawsuits retain their hold on obstetrical practice, caesarean section trends are unlikely to change.