Fetal Heart Rate Testing Research Articles

Is borderline oligohydramnios a problem at term pregnancy? a prospective study of a tertiary hospital

Aims: The objective of this study is to conduct a comparative analysis and ascertain the perinatal and early postnatal outcomes in term pregnant women who have a borderline amniotic fluid index (AFI) in comparison to those with a normal AFI.
 Methods: This prospective study was conducted on 376 pregnant women of 37-42 weeks gestational age. Ultrasound evaluation was performed, and the AFI was calculated. Borderline and normal AFI were defined as 5.1 < AFI < 8 cm and 8.1 < AFI < 24 cm, respectively. Age, body mass index, gestational age at delivery, gravida, and parity were compared between the borderline and normal AFI groups, patient demographics, obstetric data, and information on delivery complications data were recorded. Newly born babies received a thorough physical evaluation and were followed up for two months by a neonatologist. Umbilical artery pH, birth weight, admission to neonatal intensive care unit (NICU), neonatal complications were also reported.
 Results: There were 202 patients in the borderline AFI group and 174 patients in the normal AFI group. There was no statistically significant difference between groups in terms of normal delivery, operative vaginal delivery, elective cesarean delivery, or emergency cesarean delivery (p=0.088). Apgar score at 5 minutes, umbilical artery pH value, birth weight, admission to the NICU, small for gestational age, and cesarean delivery for non-reassuring fetal heart rate testing were not statistically different between the groups (p=0.139, p=0.644, p=0.790, p=0.317, and p=0.16, respectively)
 Conclusion: Our study indicates that borderline oligohydramnios does not have an adverse effect on perinatal or early postnatal outcomes in term pregnancy.

Fetal left ventricular modified myocardial performance index and renal artery pulsatility index in pregnancies with isolated oligohydramnios before 37 weeks of gestation

Objective:The aim was to evaluate fetal left modified myocardial performance index (Mod-MPI) and renal artery Doppler parameters in fetuses with isolated oligohydramnios and a normal amount of amniotic fluid.Material and Methods:This was a prospective cohort study; 25 pregnancies with isolated oligohydramnios and 25 healthy, gestational age-matched controls, between 24+0 to 36+6 weeks of gestation, were recruited. Primary outcome was to compare left modified MPI and mean fetal renal artery pulsatility index (PI). The secondary outcome was to compare adverse perinatal outcomes between the groups.Results:Mean Mod-MPI was significantly higher (p=0.001) and isovolumetric relaxation time was longer (p=0.009) in the isolated oligohydramnios group. Mean renal artery PI values were not different between the groups. Birthweight (p=0.041) and gestational age at birth (p=0.001) were significantly lower, and incidences of delivery before 37 weeks (p=0.034) and Cesarean section due to non-reassuring fetal heart rate testing (p=0.021) were significantly higher in women with isolated oligohydramnios than the control group. We found no significant relationship between Mod-MPI and adverse perinatal outcomes.Conclusion:Fetuses with isolated oligohydramnios have increased left Mod-MPI, which may be due to mild cardiac diastolic dysfunction. Increased Mod-MPI is not associated with adverse perinatal outcomes and does not seem to help in the management of pregnancies before 37 weeks of gestation with isolated oligohydramnios.

Effect of Music Intervention on Maternal Anxiety and Fetal Heart Rate Pattern During Non-Stress Test

The purpose of this cross-over experimental study was to examine effects of music intervention on maternal anxiety, fetal heart rate pattern and testing time during non-stress tests (NST) for antenatal fetal assessment. Sixty pregnant women within 28 to 40 gestational weeks were randomly assigned to either the experimental group (n=30) or control group (n=30). Music intervention was provided to pregnant women in the experimental group during NST. Degree of maternal anxiety and fetal heart rate pattern were our primary outcomes. State-trait anxiety inventory, blood pressure, pulse rate, and changes in peripheral skin temperature were assessed to determine the degree of maternal anxiety. Baseline fetal heart rate, frequency of acceleration in fetal heart rate, fetal movement test and testing time for reactive NST were assessed to measure the fetal heart rate pattern. The experimental group showed significantly lower scores in state anxiety than the control group. There were no significant differences in systolic blood pressure and pulse rate between the two groups. Baseline fetal heart rate was significantly lower in the experimental group than in the control group. Frequency of acceleration in fetal heart rate was significantly increased in the experimental group compared to the control group. There were no significant differences in fetal movement and testing time for reactive NST between the two groups. Present results suggest that music intervention could be an effective nursing intervention for alel viating anxiety during non-stress test.

Cardiac disease in pregnancy - some good news.

Two articles in this month's BJOG provide some welcome news for women with some types of cardiac disease during pregnancy. In a meta-analysis including 499 pregnancies, Lawley et al. examined maternal and perinatal outcomes in women with artificial heart valves. Less than 5% of women had the older, ball-and-cage type valves, making their data relevant to current practice. These authors reported a maternal mortality rate of 1.8% for mechanical valves, whereas no deaths were seen in women with bioprosthetic valves. Notably, in contrast to earlier studies no thrombosis-related deaths were identified in the current study. The authors appropriately attribute this improvement to advances in the design of mechanical prostheses and modified anticoagulation regimens and monitoring. Although no deaths from thrombosis were seen, the rate of thromboembolism even with newer mechanical valves was 12.5%; no thromboembolism was seen in women with bioprosthetic valves. Hence, although outcomes have improved, the two fundamental quandaries that have plagued us for decades remain. First, when considering valve replacement in women of childbearing age how does one balance the increased risk of mortality and thrombosis during pregnancy in women with mechanical valves against the need for more frequent valve replacement with bioprosthetic devices? Second, how does one balance the lower antithrombotic efficacy of heparin, which does not cross the placenta, with the potential adverse fetal effects of oral anticoagulants? Without the availability of an anticoagulant as effective as Coumadin that does not cross the placenta, this dilemma is likely to persist. In addition, Lawley et al. report a relatively high rate of pregnancy loss and perinatal deaths in women with artificial valves. To what extent these deaths may have been related to anticoagulation, or were a result of unknown factors, is uncertain. Although the value of any specific form of fetal surveillance in these women is unproven, enhanced vigilance – including serial fetal growth assessment and antepartum fetal heart rate testing – seems prudent. In a related article, Gelson et al. compared complications in first and second pregnancies in women with congenital and acquired cardiac disease. The interpretation of pooled data from patients with disparate forms of structural and functional defects must be undertaken with caution, even if these defects involve the same organ. A report of clinical outcomes in patients with liver disease in pregnancy would have little value if data from patients with both intrahepatic cholestasis of pregnancy and hepatocellular carcinoma were pooled. In addition, one might question the authors’ contention that their data apply to women with both mild to moderate heart disease, since only one woman was NYHA class II – the rest were class I. Because of the limited power of such a study to detect no difference, one should be cautious in using these data to reassure women who have encountered a complication in their first pregnancy that the next pregnancy is not likely to be any worse. However, for women with NHYA class I disease contemplating a first pregnancy who wonder whether the stress of pregnancy might impact their long-term cardiac function and prognosis, the favourable tolerance of a subsequent 40-week ‘stress test’ represented by second pregnancies in this series suggest that the answer to this question is ‘no’. Both studies are good news for pregnant women with cardiac disease. None declared. Completed disclosure of interests form available to view online as supportinginformation Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Borderline amniotic fluid index and perinatal outcomes in the uncomplicated term pregnancy

Objective: To determine perinatal outcomes in uncomplicated term pregnancies with a borderline amniotic fluid index (AFI).Methods: A retrospective review was conducted of uncomplicated singleton pregnancies at term (>37 weeks). Borderline and normal AFI were defined as 5.1 ≤ AFI ≤ 8.0 cm and 8.1 ≤ AFI ≤ 24 cm, respectively. Adverse perinatal outcomes, cesarean delivery for non-reassuring fetal heart rate testing, meconium-stained amniotic fluid, a 5-min Apgar score of <7, admission to the neonatal intensive care unit (NICU), and whether the neonate was small for gestational age were compared between the borderline and normal AFI groups.Results: Borderline AFI was not significantly associated with cesarean delivery for non-reassuring fetal heart rate testing (p = 0.513), meconium-stained amniotic fluid (p = 0.641), admission to the NICU (p = 0.368), or a 5-min Apgar score of <7 (p = 1.00). However, the number of neonates who were small for gestational age (p = 0.021) and rates of induction of labor (p < 0.001) were significantly higher in the borderline group. Multiple logistic regression analysis showed that borderline AFI was not associated with cesarean delivery for non-reassuring fetal heart rate testing (odds ratio [OR] = 0.72, 95% confidence interval [CI] 0.27–1.91, p = 0.52).Conclusion: In uncomplicated term pregnancies, a borderline AFI does not increase the risk of adverse perinatal outcomes.

Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing.

Acoustic stimulation of the fetus has been suggested to improve the efficiency of antepartum fetal heart rate testing. To assess the advantages and disadvantages of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013). All published and unpublished randomised controlled trials assessing the merits of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing. All review authors independently extracted data and assessed trial quality. Authors of published and unpublished trials were contacted for further information. Altogether 12 trials with a total of 6822 participants were included. Fetal vibroacoustic stimulation reduced the incidence of non-reactive antenatal cardiotocography test (nine trials; average risk ratio (RR) 0.62, 95% confidence interval (CI) 0.48 to 0.81). Vibroacoustic stimulation compared with mock stimulation evoked significantly more fetal movements when used in conjunction with fetal heart rate testing (one trial, RR 0.23, 95% CI 0.18 to 0.29). Vibroacoustic stimulation offers benefits by decreasing the incidence of non-reactive cardiotocography and reducing the testing time. Further randomised trials should be encouraged to determine not only the optimum intensity, frequency, duration and position of the vibroacoustic stimulation, but also to evaluate the efficacy, predictive reliability, safety and perinatal outcome of these stimuli with cardiotocography and other tests of fetal wellbeing.

Fetal manipulation for facilitating tests of fetal wellbeing.

Manual fetal manipulation has been suggested to improve the efficiency of antepartum fetal heart rate testing. The objective of this review was to assess the merits or adverse effects of the use of manual fetal manipulation in conjunction with tests of fetal wellbeing. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013). All published and unpublished randomised controlled trials assessing the use of fetal manipulation versus mock stimulation, no stimulation or other types of stimulation, used in conjunction with cardiotocography or other tests of fetal wellbeing. Three review authors independently assessed studies for inclusion, assessed trial quality and extracted data. Data were checked for accuracy. We contacted authors of published and unpublished trials for further information. We included four trials with a total of 1280 women with 2670 episodes of participation. No trial was at low risk of bias for all domains and only two trials were at low risk of bias for both selection and attrition bias.Fetal manual manipulation decreased the incidence of non-reactive antenatal cardiotocography test compared to mock or no stimulation. However, this was not statistically significant (average risk ratio (RR) 0.31, 95% confidence interval (CI) 0.02 to 6.20, I² = 96%; two trials, N = 2350). There was also no significant reduction in the mean testing time to achieve a reactive result (mean difference -2.29 minutes, 95% CI -9.61 minutes to 5.03 minutes, I² = 97%; two trials, N = 560).Comparing fetal manual manipulation with vibroacoustic stimulation, there was no significant difference in the incidence of non-reactive cardiotocography or the need for contraction-stress test.There were no data available on other outcomes such as perinatal mortality, fetal distress, maternal anxiety and gestation at delivery. There is insufficient evidence to support the use of manual fetal manipulation during cardiotocography or other tests of fetal wellbeing. More studies of manual fetal manipulation that utilises standardised protocol should be encouraged.

Maternal glucose administration for facilitating tests of fetal wellbeing

Antenatal maternal glucose administration has been suggested to improve the efficiency of antepartum fetal heart rate testing. The objective of this review was to assess the merits or adverse effects of antenatal maternal glucose administration in conjunction with tests of fetal wellbeing. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 July 2012). All published and unpublished randomized controlled trials assessing the merits of antenatal maternal (oral or intravenous) glucose administration in conjunction with tests of fetal wellbeing. Both review authors independently extracted data and assessed trial quality. Authors of published and unpublished trials were contacted for further information. A total of two trials, involving 708 participants, were included. Antenatal maternal glucose administration did not decrease the incidence of non-reactive antenatal cardiotocography tests. Antenatal maternal glucose administration has not been shown to reduce non-reactive cardiotocography. More trials are needed to further substantiate this and to determine not only the optimum dose, but also to evaluate the efficacy, predictive reliability, safety and perinatal outcome of glucose administration in conjunction with cardiotocography and also other tests of fetal wellbeing.

Conventional Linear Criteria with Sample Entropy in the Interpretation of Reactive Antepartum Fetal Heart Rate Tracings

Objective: To compare the test duration times and rate of nonreactive results between the conventional linear reactive criteria (CLRC) and the modified nonlinear reactive criteria (MNRC) in electronic fetal heart rate (FHR) monitoring. The MNRC are the CLRC with the addition of approximate entropy or sample entropy. Methods: One thousand women with singleton pregnancies between 30 and 37 weeks’ gestation were selected. They visited Hanyang University Hospital for non-stress tests (NSTs). In these patients, FHR tracings were recorded for 50 min including the first and second 20 min of NST and 10 min of vibroacoustic stimulation test. All patients had a reactive NST with CLRC in these antepartum FHR tests. The rate of nonreactive tests and test duration times of these linear and nonlinear criteria were calculated and compared. Results: The rate of nonreactive tests within a 20- and 40-min period with the MNRC (6.8 and 1.2%) was significantly lower than with the CLRC (35.2 and 10.5%, respectively; p < 0.001). To meet the reactive criteria, the mean durations of the MNRC and the CLRC were 11.47 (95% CI, 11.11–11.84) and 18.45 (95% CI, 17.79–19.12) min, respectively (p < 0.001). The MNRC led to a significant reduction in testing time of 37.8% compared to the CLRC. The rate of reactive tests using only sample entropy (0.20), calculated over 5-min segments of FHR tracings, was 88.3% (95% CI, 88.0–88.7). It was close to the results using the MNRC (93.2%) in the 20-min time window. Conclusion:The use of the MNRC significantly reduced the test duration times and decreased the rate of nonreactive tests when compared to the CLRC. It may be useful in providing more rapid and accurate assessment of the fetus in electronic FHR monitoring.

Doppler Ultrasonography in Assessment of Fetal Well-being

After completing this article, readers should be able to: 1. Describe the calculations used to measure fetal systemic and placental vascular impedance in the umbilical artery via Doppler ultrasonography. 2. Delineate the two primary uses of measurement of middle cerebral artery flow velocity. 3. List the fetal conditions in which Doppler flow velocity has been studied. The Doppler principle, discovered by Johann Christian Andreas Doppler in 1842, (1) was used initially in astronomy and later in the military, in various branches of industry, and more recently in medicine. Doppler shift is based on the perceived change in frequency of an energy waveform as the source and the receiver move toward or away from each other. The Doppler shift principle applies to light waves as well as sound waves. In biology, Doppler ultrasonography is used noninvasively, primarily to measure flow velocity in blood vessels. Flow velocity depends on the volume and speed of effluent relative to the diameter of the vessel. Estimating fetal vascular resistance through study of Doppler flow velocity provides a means to assess, albeit indirectly, fetal physiology and pathology. Johnson and colleagues (2) in 1965, made the earliest mention of the use of Doppler effect in obstetrics. The use of Doppler ultrasonography to investigate the pattern of waveforms in the umbilical artery during pregnancy initially was reported in 1977 by Fitzgerald and Drumm. (3) Subsequently, Wladimiroff and associates (4) reported on Doppler assessment of cerebral blood flow in the human fetus. The addition of color mapping has enhanced the utility of the Doppler effect in sonographic assessment of the fetus. The fetal umbilical artery (UA) and middle cerebral artery (MCA) have evolved as the primary targets of fetal Doppler studies (Figs. 1 and 2). Figure 1. Color Doppler view of circle of Willis. Arrows show anterior (ACA), middle (MCA), and posterior cerebral …

The impact of maternal ketonuria on fetal test results in the setting of postterm pregnancy

Objective: The aim of this study was to determine whether ketonuria, a commonly assessed urinary marker of maternal starvation and dehydration, is associated with abnormal fetal test results in the setting of postterm pregnancy. Study Design: During a 4-year period (January 1993–December 1996), a total of 3655 visits for antepartum maternal-fetal testing of postterm pregnancies (≥41 weeks’ gestation) occurred at our institution. Maternal assessment included vital signs and urinalysis. The presence and degree of maternal ketonuria was correlated against abnormal results of fetal heart rate tests, nonstress tests, amniotic fluid index measurements, and biophysical profile scores performed on the same day. Results: There were 3601 encounters suitable for inclusion in the study. Clinically detectable ketonuria occurred in 10.9% of the patients studied. Patients with clinically detectable ketonuria were at increased risk relative to patients without ketonuria for abnormal outcomes during postterm testing, including the presence of oligohydramnios (24% vs 9.3%; P <.0001 ), nonreactive nonstress tests (6.2% vs 2.15%; P <.0001), and fetal heart rate decelerations (14% vs 9.2%; P =.0039 ). Conclusion: Maternal ketonuria among patients with postterm pregnancy was associated with a >2-fold increase in the occurrence of oligohydramnios, a 3-fold increase in nonreactive nonstress tests, and a significant increase in fetal heart rate decelerations. Further studies are required to evaluate the potential benefits of treating ketonuria before fetal testing. (Am J Obstet Gynecol 2001;184:713-8.)

Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing.

Acoustic stimulation of the fetus has been suggested to improve the efficiency of antepartum fetal heart rate testing. The objective of this review was to assess the merits or adverse effects of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing. We searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: October 2000. All published and unpublished randomized controlled trials assessing the merits of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing. Both reviewers independently extracted data and assessed trial quality. Authors of published and unpublished trials were contacted for further information. A total of seven trials with a total of 4325 participants were included. Fetal vibroacoustic stimulation reduced the incidence of non-reactive antenatal cardiotocography test (odds ratio (OR) 0.61, 95% confidence interval (CI) 0.49-0.75) and reduced the overall mean cardiotocography testing time (weighted mean difference (WMD) -4.55 minutes, 95% CI -5.96 minutes to -3.14 minutes). Vibroacoustic stimulation evoked more than mock stimulation when used in conjunction with fetal heart rate testing (OR 0.08, 95% CI 0.06-0.12). Vibroacoustic stimulation offers benefits by decreasing the incidence of non-reactive cardiotocography and reducing the testing time. Further randomized trials should be encouraged to determine not only the optimum intensity, frequency, duration and position of the vibroacoustic stimulation, but also to evaluate the efficacy, predictive reliability, safety and perinatal outcome of these stimuli with cardiotocography and other tests of fetal wellbeing.

NONSTRESS TESTING AND CONTRACTION STRESS TESTING

Antepartum fetal heart rate (FHR) testing, including the nonstress test and contraction stress test, has evolved in clinical usage over the past 3 decades. Although the nonstress test has become a standard of care in high-risk pregnancy, it has been modified by the use of fetal stimulation (vibroacoustic stimulation) and the addition of automated fetal movement recording (actocardiotocography). In all of its formats, antepartum FHR testing has been associated with reduction of preventable fetal loss. More recently, there have been attempts to improve test efficacy by computer-enhanced approaches.

Cervical Ripening With Mifepristone Before Labor Induction

In Brief Objective To determine the efficacy and safety of mifepristone for cervical ripening in post-term pregnancies. Methods Women with post-term pregnancies and Bishop scores less than 6 were assigned randomly to mifepristone (41 patients) or placebo (42 patients). Mifepristone was given orally in a dose of 400 mg. Efficacy was assessed by change in the Bishop score within 48 hours after treatment; a score of 6 or greater was considered a “strict” success. An “extended” success rate was defined, including all patients with scores of at least 6 or those who delivered within 48 hours of treatment. Antenatal safety was assessed by fetal heart rate testing before and throughout labor. Neonatal safety was assessed by Apgar score, arterial or venous pH of cord blood, and blood glucose level during the first 48 hours. Analysis used Student t test for continuous variables, Kruskal-Wallis test for ordinal data, and χ2 for categoric variables. Results Strict success was achieved in 10 of 18 mifepristone patients (55%) evaluated for Bishop score on day 2 versus 8 of 29 placebo patients (27.5%) (P = .004). Extended success was achieved in 33 mifepristone patients (80.5%) and 21 placebo patients (50.0%) (P = .004). There were no statistical differences with regard to number of cesareans or fetal and neonatal safety. Conclusion Mifepristone proved effective for cervical ripening and reduced the time to delivery compared with placebo, but it did not improve the rate of cesarean. Our study did not include enough pregnancies to reach conclusions about fetal or neonatal safety. Mifepristone promotes cervical ripening in women with post-term pregnancies and reduces the time to delivery, but it does not lower the cesarean rate.

Cervical ripening with mifepristone before labor induction: a randomized study

Objective: To determine the efficacy and safety of mifepristone for cervical ripening in post-term pregnancies. Methods: Women with post-term pregnancies and Bishop scores less than 6 were assigned randomly to mifepristone (41 patients) or placebo (42 patients). Mifepristone was given orally in a dose of 400 mg. Efficacy was assessed by change in the Bishop score within 48 hours after treatment; a score of 6 or greater was considered a “strict” success. An “extended” success rate was defined, including all patients with scores of at least 6 or those who delivered within 48 hours of treatment. Antenatal safety was assessed by fetal heart rate testing before and throughout labor. Neonatal safety was assessed by Apgar score, arterial or venous pH of cord blood, and blood glucose level during the first 48 hours. Analysis used Student t test for continuous variables, Kruskal-Wallis test for ordinal data, and χ 2 for categoric variables. Results: Strict success was achieved in 10 of 18 mifepristone patients (55%) evaluated for Bishop score on day 2 versus 8 of 29 placebo patients (27.5%) ( P = .004). Extended success was achieved in 33 mifepristone patients (80.5%) and 21 placebo patients (50.0%) ( P = .004). There were no statistical differences with regard to number of cesareans or fetal and neonatal safety. Conclusion: Mifepristone proved effective for cervical ripening and reduced the time to delivery compared with placebo, but it did not improve the rate of cesarean. Our study did not include enough pregnancies to reach conclusions about fetal or neonatal safety.

Antepartum cervical ripening: Applying prostaglandin E 2 gel in conjunction with scheduled nonstress tests in postdate pregnancies

OBJECTIVE: Our purpose was to evaluate whether inserting prostaglandin E 2 gel at the time of scheduled nonstress tests in patients with postdate pregnancies can decrease rates of intervention. STUDY DESIGN: A multicenter pilot study enrolled women with postdate pregnancies with Bishop score ≤6 who were undergoing antepartum fetal heart rate testing. Patients were randomized in a double-blind fashion to receive either a prostaglandin E 2 intracervical gel (Prepidil) or a placebo gel after each of their scheduled nonstress tests. RESULTS: There were no significant differences in the number of antepartum tests, labor inductions, or cesarean sections, the maximum oxytocin dosage, or the interval from admission to delivery in the prostaglandin E 2 gel and placebo gel groups ( n = 90). In the subset of patients with a Bishop score between 3 and 6 (63 patients), there were fewer inductions in the prostaglandin E 2 group (30% vs 55%, P < .05). CONCLUSION: Application of prostaglandin E 2 gel at the time of scheduled antepartum testing in patients with postdate pregnancies with unfavorable cervices decreased the induction rate only among patients with intermediate Bishop scores. (Am J Obstet Gynecol 1998;179:453-8.)

Serial amniotic fluid index in severe preeclampsia: A poor predictor of adverse outcome

OBJECTIVE: The purpose of the study was to determine the relationship between low amniotic fluid index and intrauterine growth restriction and nonreassuring fetal testing in patients with severe preeclampsia. STUDY DESIGN: We reviewed the medical records of 136 women with severe preeclampsia managed conservatively for at least 48 hours. Patients were followed up with a daily nonstress test and amniotic fluid index. We evaluated amniotic fluid index ≤5 cm and ≤7 cm, measured on admission or just before delivery (i.e., final), and attempted to correlate these findings with the incidence of nonreassuring fetal testing necessitating cesarean section or the incidence of intrauterine growth restriction (birth weight ≤10th percentile). RESULTS: One hundred seven patients had a cesarean section, but only 42 (39%) of these were for a nonreassuring fetal heart rate tracing or a persistent biophysical profile of ≤4, and 38 (36%) of the pregnancies resulted in infants with intrauterine growth restriction. During expectant management, the amniotic fluid index worsened for 61 (45%) patients and improved or remained the same for 75 (55%). For those with an amniotic fluid index of ≤5 cm both on admission and at delivery, there was a significantly higher incidence of intrauterine growth restriction compared with those with an amniotic fluid index >5 cm (p = 0.007 and p = 0.029, respectively). However, there was no association between intrauterine growth restriction and an amniotic fluid index ≤7 cm. Moreover, there was no difference in the frequency of nonreassuring fetal heart rate testing on the basis of amniotic fluid volume (p = 0.59) or intrauterine growth restriction (p = 0.4). CONCLUSIONS: For women with severe preeclampsia remote from term, an amniotic fluid index ≤5 cm is predictive of intrauterine growth restriction but lacks sensitivity. There is no association between the amniotic fluid index status and frequency of cesarean section for fetal distress or nonreassuring fetal testing. (Am J Obstet Gynecol 1996;175:1018-23.)

Vibroacoustic Stimulation

Vibroacoustic stimulation of the human fetus profoundly alters fetal behavior and heart rate. Many authors have reported success using this technique to improve the efficiency of antepartum fetal heart rate testing without changing the predictive reliability of the tests. Vibroacoustic stimulation has other potential advantages in the antepartum assessment of fetal well-being and in provoking fetal activity to improve ultrasonic visualization. From an experimental standpoint, vibroacoustic stimulation offers a unique opportunity to assess how the fetus responds to the external environment. The available information suggests that exposure of the fetus to vibroacoustic stimulation is clinically safe. Additional research is needed to characterize the optimal frequency, duration, intensity, and choice of stimulus to provide consistent responses. The literature presents a confusing array of studies using different methods, which makes comparison of results among institutions and investigators difficult. Vibroacoustic stimulation appears to be a reasonable and safe clinical technique. Additional prospective investigation is necessary to characterize further how this technique can be more useful clinically.

Antepartum surveillance for a history of stillbirth: When to begin?

OBJECTIVE: A history of stillborth is universally accepted as an indication for antepartum fetal heart rate testing. Our goal was to examine when fetal testing should begin in an otherwise healthy patient with a history of stillbirth. STUDY DESIGN: This is a nonconcurrent cohort study of patients who were seen for antepartum surveillance from January 1979 to December 1991 with a history of stillbirth as the only indication for testing. Subsequent pregnancies were evaluated for adverse outcomes and abnormal antepartum test results. RESULTS: There was one case of recurrent stillbirth among the 300 study patients. Nineteen patients (6.4%) had one or more positive antepartum surveillance tests (positive contraction stress test or biophysical profile ≤4). Three patients (1%) had positive tests before 32 weeks, all of whom were subsequently delivered without incident at term. Three patients were delivered for positive tests at <36 weeks, one by cesarean section for fetal distress. We could not detect a relationship between the gestational age of the previous stillborn and the incidence of abnormal tests or fetal distress in subsequent pregnancies. CONCLUSION: Antepartum surveillance should begin at ≥32 weeks in the healthy pregnant woman with a history of stillbirth.

Transabdominal amnioinfusion in preterm pregnancies complicated by fetal growth restriction, oligohydramnios and umbilical cord compression.

Fetal growth restriction with oligohydramnios occurring in the preterm gestation is associated with significant fetal morbidity and mortality. We investigated the possibility that transabdominal amnioinfusion might relieve acute cord compression and allow prolongation of gestation long enough to administer corticosteroids. Four patients with fetal growth restriction, oligohydramnios and evidence of significant cord compression with otherwise reassuring fetal heart rate testing underwent transabdominal amnioinfusion. Pregnancy was prolonged 22, 38, 10 and 9 days, and cord compression was relieved in all cases. One patient showed findings consistent with reversal of chronic hypoxemia with stabilization of amniotic fluid index measurements in the normal range and normalization of fetal growth. Transabdominal amnioinfusion may be useful as an adjunctive technique to prolong pregnancy in preterm gestations with fetal growth restriction, oligohydramnios and evidence of umbilical cord compression.