Nonreassuring Fetal Heart Tracing Research Articles

Intrauterine Growth Restriction and Oligohydramnios among High-Risk Patients

The purposes of this study were (1) to determine the prevalence of oligohydramnios (amniotic fluid index < 5.0 cm) among fetuses with intrauterine growth restriction (IUGR) and newborns identified as small for gestational age (SGA), and (2) among fetuses with IUGR, to determine the predictive accuracy of amniotic fluid index (AFI) < or = versus > 5.0 cm for adverse peripartum outcomes. This was a retrospective review of high-risk pregnancy that had reliable gestational age (GA) and needed weekly biophysical profile (BPP). Along with 95% confidence intervals (CIs), we calculated the likelihood ratios (LRs) and used guidelines promulgated by Evidence-Based Medicine Working Group. Among the 1859 singletons undergoing BPP, IUGR (estimated fetal weight < 10% for GA) was suspected in 22% (n = 410) and the prevalence of oligohydramnios was 6% (95% CI, 4 to 8%). SGA (birthweight < or = 10%) occurred among 28% (n = 517) of newborns and oligohydramnios was noted in 6% (95% CI, 4 to 8%). Among fetuses with IUGR, the LR of oligohydramnios to predict cesarean delivery for nonreassuring fetal heart tracing was 2.0 (range, 0.8 to 5.0); for newborns small for gestational age, 1.9 (range, 1.2 to 3.1), and for neonatal intensive care unit admission, 1.4 (range, 0.6 to 2.3) More than 90% of patients with IUGR or SGA have AFI > 5.0 cm, and oligohydramnios with IUGR is a poor predictor of peripartum complications.

Inpatient versus Outpatient Management of Monoamniotic Twins and Outcomes

A recent literature review holds that approximately one in 10 cases of monoamniotic twinning ends with perinatal death. An entangled umbilical cord may be fatal and is not a predictable complication. This multicenter retrospective records review was undertaken to learn whether outcomes might be improved by hospitalization when monoamniotic twins are at 24 to 28 weeks gestation and close fetal surveillance is maintained until delivery at 32 to 34 weeks. Review of a recent 10-year period at 4 centers totaling approximately 15,000 deliveries annually yielded 23 sets of monoamniotic twins, 11 managed as inpatients and 12 given outpatient care. Women in the inpatient group had continuous external fetal monitoring and underwent ultrasound (to monitor fetal growth) and Doppler flow studies at 4-week intervals. Outpatient management included nonstress testing or biophysical profiling at least 3 times a week. There were no fetal deaths in the inpatient group, but 3 such deaths occurred with outpatient management. Inpatients had gestational ages of 30 to 36 weeks when delivered. There were 7 elective operative deliveries in the inpatient group, and 4 sections were done because of a nonreassuring fetal heart tracing. Eleven infants had respiratory distress syndrome; 3, intraventricular hemorrhage; 3, anomalies; and one, sepsis. Two infants were apparently free of complications. In the outpatient group, gestational ages at delivery ranged from 27 to 34 weeks. Three cesarean sections were done electively and 6 others because of a nonreassuring fetal heart tracing. There were 2 cases each of preterm labor and intrauterine fetal demise and one each of severe preeclampsia, increased liver enzymes, and abruption. Sixteen infants in this group had respiratory distress syndrome, 4 had sepsis, and one each had intraventricular hemorrhage and atrial septal defect. Three infants each had patent ductus arteriosis and retinopathy of prematurity, whereas 4 were free of complications. It is not likely that a randomized trial comparing inpatient with outpatient management of monoamniotic twin pregnancies will prove feasible. Pending such a study, the investigators propose that inpatient management be considered.

Therapeutic amnioinfusion for intrapartum fetal distress using a pediatric feeding tube

Objective: To evaluate the role of therapeutic amnioinfusion using a pediatric feeding tube in cases of intrapartum fetal distress. Methods: A randomized clinical trial including 438 women admitted in labor at Assiut University Hospital with nonreassuring fetal heart rate tracing. Using sealed opaque envelopes, the women were randomized to 2 groups. In the amnioinfusion group they underwent transcervical amnioifusion (1000 mL of warmed sterile saline solution) in addition to conventional treatment. In the control group they received conventional treatment only. The primary outcome was cesarean section rate for fetal distress. The secondary outcomes were neonatal and maternal complications. Results: The amnioinfusion group showed a significant reduction in the rate of cesarean section for fetal distress (relative risk [RR], 0.7; 95% confidence interval [CI], 0.6–0.83), and a 30% reduction in abnormal fetal heart rate patterns (RR, 0.7; 95% CI, 0.6–0.83). Significantly fewer newborns had Apgar scores less than 7 at 1 and 5 min in the amnioinfusion group than in the control group (RR, 0.38; 95% CI, 0.26–0.55 and RR, 0.31; 95% CI, 0.15–0.64, respectively). Significantly fewer newborns had meconium below the vocal cords in the amnioinfusion group than in the control group (RR, 0.36; 95% CI, 0.13–0.97). Moreover, 14 newborns in the amnioinfusion group needed admission to the intensive care unit vs. 31 newborns in the control group. There were no significant differences between the 2 groups regarding the incidence rates of uterine hypertonus and maternal temperature higher than 38 °C. Conclusion: Therapeutic amnioinfusion is a simple and effective intervention that reduces the rates of cesarean section for intrapartum nonreassuring fetal heart tracing. In under-resourced settings, it can be performed using inexpensive catheters.

Prospective, Randomized Trial Comparing General with Spinal Anesthesia for Cesarean Delivery in Preeclamptic Patients with a Nonreassuring Fetal Heart Trace

Prospective, Randomized Trial Comparing General with Spinal Anesthesia for Cesarean Delivery in Preeclamptic Patients with a Nonreassuring Fetal Heart Trace

THIS MONTH IN ANESTHESIOLOGY

THIS MONTH IN ANESTHESIOLOGY

Unusual presentation of echogenic bowel: postnatal diagnosis of congenital myofibromatosis

Description of case(s): A 27-year-old primigravid woman presented for ultrasound at 25 weeks for concern over large fetal size. Biometry was appropriate for gestational age. Fluid, movement, and tone were unremarkable. Asymmetry of the cerebral ventricles was noted, 10 mm vs. 5 mm. Additionally, a fairly well-circumscribed cystic and solid area was noted midline within the fetal abdomen below the stomach. The patient underwent an amniocentesis; karyotype and TORCH studies were normal. Subsequent ultrasound examinations at 29 and 33 weeks revealed a decreased prominence of the ventricular asymmetry. The previously noted mass in the abdomen was no longer distinguishable from the normal abdominal contents though the bowel had a stippled appearance. Fetal monitoring was started at 33 weeks for mild growth restriction. Delivery was at 34.4 weeks by Cesarean section due to abnormal Dopplers and a nonreassuring fetal heart tracing.

Randomized trial of concurrent oxytocin with a sustained-release dinoprostone vaginal insert for labor induction at term

Objective: The purpose of this study was to determine whether the concurrent administration of oxytocin with sustained-release dinoprostone results in shorter induction times when compared with oxytocin after the removal of the dinoprostone insert. Study Design: Women with singleton pregnancies at ≥36 weeks, vertex presentations, reactive nonstress tests, no prior uterine scar, intact membranes, and Bishop scores of ≤6 were randomly assigned to receive oxytocin either immediately after placement of a sustained-release dinoprostone insert (immediate) or 30 minutes after its removal (delayed). The primary outcome was the time interval from induction to delivery. Results: Seventy-one patients were enrolled (immediate, 34 patients; delayed, 37 patients). There were no differences between treatment groups in nonreassuring fetal heart tracings, excess uterine activity, and epidural use. The mean time from dinoprostone placement until delivery was 544 minutes, shorter in the immediate group (972 vs 1516 minutes; P =.001). The proportion of deliveries within 24 hours was higher (90% vs 53%; P =.002) in the immediate group. Cesarean delivery rates were similar between the immediate and delayed groups (16% vs 13%; P =.73). No adverse maternal or neonatal outcomes were observed with concurrent therapy. Conclusion: Oxytocin that is administered concurrently with sustained-release dinoprostone significantly shortens induction-to-delivery times and results in a higher proportion of vaginal deliveries of ≤24 hours with no apparent adverse effects. (Am J Obstet Gynecol 2002;186:61-5.)

Fetal heart rate abnormalities after regional analgesia for labor pain: The effect of intrathecal opioids

Background and Objectives: Intrathecal opioids used to relieve labor pain have been associated with uterine hyperactivity and nonreassuring fetal heart rate abnormalities. We retrospectively evaluated all charts of singleton, term, vertex-presenting parturients in active labor requesting neuraxial pain relief during a 1-year period for the occurrence of nonreassuring fetal heart rate tracings. Methods: Three different strategies to relieve labor pain were routinely used in our department: conventional epidural using 10 mL bupivacaine 0.125% and sufentanil 0.75 μg/mL; combined spinal and epidural (CSE) using intrathecal sufentanil (7.5 μg); and CSE using intrathecal bupivacaine (2.5 mg) and sufentanil (1.5 μg). Charts (n = 1,293) were evaluated for nonreassuring fetal heart tracings and uterine hyperactivity as well as for neonatal and labor outcome. Results: Intrathecal sufentanil (7.5 μg) produced significantly more nonreassuring tracings and uterine hyperactivity. However, this did not result in more cesarean deliveries or detrimental neonatal outcome. Conclusion: Based on this retrospective analysis, we conclude that intrathecal sufentanil in a dose of 7.5 μg has the potential to result in more nonreassuring fetal heart rate tracings compared with both intrathecal analgesia using a bupivacaine (2.5 mg)/sufentanil (1.5 μg) mixture and epidural analgesia using bupivacaine, sufentanil, and epinephrine. Reg Anesth Pain Med 2001;26:257-262.

Intrapartum fetal heart rate tracings: accuracy of interpretation is unaffected by level of providers’ training

Objective: The ACOG Technical Bulletin of July 1995 suggests that intrapartum fetal heart rate patterns should be interpreted as reassuring or nonreassuring. The bulletin describes a nonreassuring fetal heart tracing (FHT) as having one or more of the following components: abnormal baseline (ie, tachycardia, decreased variability); the presence of variable decelerations that are persistent, progressively deeper and longer lasting; late decelerations that are persistent; prolonged deceleration greater than 60 seconds; and a sinusoidal heart rate pattern. A reassuring FHT implies the absence of these patterns. We sought to investigate the accuracy of interobserver interpretation of FHT in labor. Method: Three hundred sixty intrapartum FHTs were evaluated by obstetric residents, attendings, nurses, and maternal–fetal medicine specialists (MFMs). Tracings were accompanied by a questionnaire addressing classification of FHT, a proposed approach, and anticipated fetal outcome. Participants were blinded to actual outcomes. Results: 1) Of reassuring FHTs, 96% were identified with no significant difference in rate of identification in each provider group; 2) 80% of nonreassuring patterns were identified with similar rates of identification within each provider group; and 3) there was no significant interobserver difference in the correct interpretation of tracings between residents (75.5%), attendings (81.9%), MFMs (77.4%), and nurses (85%). Conclusion: Our data suggest that theTechnical Bulletin’s recommended classification of intrapartum FHT tracings as reassuring versus nonreassuring is successful in providing a simple, accurate method of recognition regardless of the providers’ level of obstetric training.

Spontaneous umbilical cord hematoma: a rare cause of acute fetal distress.

Spontaneous umbilical cord hematoma is very rare. We present a newborn who was discovered to have a spontaneous fetal umbilical cord hematoma. A nonreassuring fetal heart tracing complicated the first and second stages of labor. The only pathological finding was a short umbilical cord, which could have contributed to the rupture of fetal vessels.

Amniotic fluid distribution in predicting perinatal outcome in patients with ruptured membranes

To determine if amniotic fluid distribution predicts perinatal outcome in women with spontaneously ruptured membranes. Patients presenting for labor and delivery with spontaneously ruptured membranes had amniotic fluid indices determined upon admission. Those with greater than 50% of their amniotic fluid in the upper quadrants were placed in the upper-greater group and those with greater than 50% in the lower quadrants were placed in the lower-greater group. The groups were compared with respect to meconium staining, 1- or 5-minute Apgar scores below 7, persistent variable or late decelerations, umbilical arterial or venous pH below 7.20, cesarean for non-reassuring fetal heart rate monitoring, and neonatal intensive care unit admissions. One hundred women were studied, 60 in the upper-greater group and 40 in the lower-greater group. Significant differences between upper-greater and lower-greater distributions were noted in meconium staining (28.3% compared with 0%, P < .001), 1-minute Apgar score below 7 (16.7% compared with 2.5%, P < .027), variable decelerations (63.3% compared with 25.0%, P < .001), late decelerations (23.3% compared with 0%, P < .001), and cesarean for non-reassuring fetal heart tracing (11.6% compared with 0%, P < .025). The negative predictive values for all of the variables studied were in the range 92.5-100%, with the exception of variable decelerations (75%). Amniotic fluid distribution predicts perinatal outcome in patients with ruptured membranes. This test's high negative predictive value indicates its potential as a valuable screening tool. These results may provide additional guidance in defining the intrapartum management of patients presenting with ruptured membranes.

Risk factors for meconium aspiration syndrome

To identify potential predictors of meconium aspiration syndrome (MAS) in pregnancies complicated by moderate or thick meconium-stained amniotic fluid (AF). In the period 1990-1993, 937 vertex singleton pregnancies with moderate or thick meconium-stained AF were delivered; of these, 39 neonates developed MAS and 898 did not. The two groups were compared retrospectively according to maternal findings, pregnancy outcome, and neonatal complications, using univariate analysis (P < .05 considered significant) and stepwise multiple logistic regression analysis to identify independent significant factors for prediction of MAS and to calculate odds ratios (OR) and 95% confidence intervals. The two groups had a similar mean gestational age at delivery and birth weight. They also had similar incidences of post-dates pregnancies, small and large for gestational age infants, and amnioinfusion use. Univariate analysis identified significant differences between the two groups in 13 variables, two of which were excluded from logistic analysis because of inadequate data. Logistic regression analysis identified only six variables with independent, statistically significant effects on MAS: admission for induction with nonreassuring fetal heart tracing (OR 6.9), need for endotracheal intubation and suctioning below the vocal cords (OR 4.9), 1-minute Apgar score of 4 or less (OR 3.1), present cesarean delivery (OR 3.0), and previous cesarean delivery (OR 2.5). Cigarette smoking was associated with a lower risk for MAS (OR 0.07). The presence of at least one of the five risk factors had a sensitivity of 92%, a specificity of 56%, a positive predictive value of 8%, and a negative predictive value of 99% for MAS. Considering the high negative predictive value of the test, infants without any risk factors will not develop MAS and thus can be safely allowed to room with their mothers. Furthermore, this model helps to identify infants who may benefit from 24-hour observation and in counseling women about the neonatal risk for developing MAS.