Relationship of early intrapartum fetal heart rate patterns to subsequent patterns and fetal outcome

This study evaluated subsequent fetal heart rate (FHR) patterns and fetal outcome in laboring women with normal or abnormal initial FHR patterns. Four hundred term gravidas presenting in the latent phase of labor were studied. Ninety (22.5%) exhibited abnormalities on the initial tracing, with the majority of those abnormalities (58.9%) including mild variable decelerations, either alone or in combination with other abnormalities. An analysis of the outcome for those patients revealed a significant increase in cesarean delivery for fetal distress and depressed one-minute Apgar scores when compared to patients with initially normal tracings. Analysis of subsequent FHR patterns in that group showed a significant increase in the incidence of atypical variable declerations and bradycardia. Patients with more than one abnormality on the initial FHR tracing showed a greater incidence of loss of variability, loss of reactivity and bradycardia on subsequent FHR tracings. Likewise, pregnancy outcome for this group was remarkable for an increased risk of meconium staining, cesarean delivery for fetal distress and depressed one-minute Apgar scores. An abnormal initial FHR tracing seems to be associated with the subsequent development of ominous FHR patterns and increased fetal morbidity, particularly when more than one abnormality is present on the initial tracing.     

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.     

Clinical significance of fetal heart rate patterns during labor: IV. Agonal patterns

The characteristics of fetal heart rate (FHR) patterns were reviewed in 11 cases where the infants died either intrapartum or within eight hours of birth as a consequence of distress during labor without prior recovery. The neonatal charts and the autopsy reports were also reviewed. The infants were grouped according to gestational age as premature (four), term (four), and postmature (three). Similarities and differences were studied in an attempt to delineate some common underlying factors. The premature fetuses have an extraordinary capacity to withstand clinical signs of severe distress (late deceleration and fixed and tachycardic base line) for many hours until the very moment of death and rarely pass meconium. The term fetuses can withstand less prolonged periods of severe distress, the fixed FHR base line and impressive decelerations preceding immediate death; they consistently passed meconium, three of four had aspirated meconium. All of the postterm fetuses had massive meconium aspiration, but the FHR patterns had a bizarre appearance; several hours before death some late decelerations were followed by tachycardia and fixed base lines but no decelerations. Subsequent occurrence of erratic severe decelerations immediately preceded sudden death. Possible reasons for these different pathophysiologic responses are discussed. In the study of FHR tracings, a variable of utmost importance is chronologic age of gestation. Its value cannot be overemphasized for an accurate interpretation of the fetal condition and good decisions for management.     

Risk factors for meconium aspiration in meconium stained amniotic fluid.

Meconium aspiration syndrome (MAS) is a life-threatening respiratory disease in infants born through meconium stained amniotic fluid (MSAF). The purpose of this study was to determine risk factors for MAS in the newborns of mothers who had meconium stained amniotic fluid in labour. A retrospective study of all full-term pregnancies with MSAF from May 2003 to October 2004 was designed at a teaching hospital. Development of MAS was the primary outcome. Maternal details, mode of delivery and neonatal details (Apgar score, reassuring or non-reassuring fetal heart rate tracing and birth weight) were evaluated. During the study period, there were 2,603 deliveries of whom 302 (11.6%) had MSAF. MAS developed in 64 of these infants (21.1%). Compared with healthy neonates with MSAF, those with MAS had higher rate of non-reassuring fetal heart rate (FHR) tracing, thick meconium and Apgar score < or =5 at 5 min. The neonatal birth weight was lower in the MAS group, maternal age, parity, gestational age and mode of delivery were not significantly different in the two group. We found the severity of meconium, low Apgar score at 5 min and non-reassuring FHR tracing was associated with MAS in MSAF pregnancies.     

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.     

Prophylactic transcervical amnioinfusion in laboring women with oligohydramnios.

OBJECTIVES: Evaluation of prophylactic intrapartum amnioinfusion in women with oligohydramnios. METHODS: Assiut University Hospital during the period from February 2000 to September 2001, 160 laboring women with oligohydramnios [amniotic fluid index (AFI) 相似文献   

Fetal distress during labour in diabetic pregnancy

The frequency of fetal distress in labour was studied in 46 diabetic women and in 46 non-diabetic matched controls. Fetal distress was assessed by electronic fetal heart rate (FHR) monitoring and fetal scalp blood pH determinations in late first stage of labour. Ominous FHR and/or low pH (less than 7.26) was more common in the diabetic group than in the control group (17.4% and 10.9%, respectively) but the difference was not statistically significant. The frequency of caesarean section and low Apgar score at 1 min was significantly higher in the diabetic group (P less than 0.05). There was no correlation between maternal blood glucose regulation and the occurrence of fetal distress in the diabetic group. The results suggest that fetal distress may be slightly more common in labour in diabetic women compared with controls managed in a similar way. Careful FHR monitoring and liberal use of fetal scalp blood pH determinations is recommended.     

Variables associated with meconium aspiration syndrome in labors with thick meconium

OBJECTIVE: To examine the possible maternal and fetal variables associated with meconium aspiration syndrome in labors with thick meconium. STUDY DESIGN: The fetal heart rate tracings, cord pH, Apgar scores and maternal risk factors were evaluated in singleton pregnancies with vertex presentation and thick meconium in labor. The study included 33 consecutive fetuses which developed a moderate or severe meconium aspiration syndrome and 104 consecutive fetuses which had a favorable outcome. RESULTS: Significant differences between fetuses with meconium aspiration syndrome and healthy fetuses were found in the following parameters: baseline FHR (154+/-17 vs. 136+/-10, P<0.0001), small accelerations/30 min (1.47+/-1.52 vs. 3.04+/-1.2, P<0.0001), large accelerations/30 min (1.46+/-1.96 vs. 3.5+/-2.31, P<0.0003), decelerations/30 min (4.9+/-3.9 vs. 2.4+/-2.1, P<0.0034), number of fetuses with reduced beat-to-beat variability (9/33 vs. 0/104, P<0.0001), cord pH (7.21+/-0.09 vs. 7.33+/-0.08, P<0.0013) and Apgar scores at 1 min (5+/-2 vs. 8+/-1, P<0.0001) and Apgar scores at 5 min (8+/-2 vs. 9.7+/-0.6, P<0.0001). Maternal risk factors were found in two of 33 sick infants and in 13 of 104 healthy infants. CONCLUSION: Thick meconium by itself is not associated with adverse fetal outcome. However, the incidence of meconium aspiration syndrome increases in cases of a non-reassuring FHR.     

Fetal acoustic stimulation in the early intrapartum period as a predictor of subsequent fetal condition

Fetal acoustic stimulation has recently received much attention in the literature. This study evaluates fetal acoustic stimulation in the early intrapartum period as a predictor of subsequent fetal condition. The study group consisted of 201 patients, approximately 60% of whom had complicated pregnancies. All were in the latent phase of labor with singleton, vertex-presenting fetuses. Gestational age ranged from 37 to 43 weeks. Fourteen of the 201 fetuses (7%) showed a nonreactive response to fetal acoustic stimulation and those fetuses were at significantly greater risk of initial and subsequent abnormal fetal heart rate patterns, meconium staining, and cesarean delivery because of fetal distress and Apgar scores less than 7 at both 1 and 5 minutes. Transient fetal heart rate decelerations after a reactive response occurred in 25% of patients; however, fetal outcome was not worse in this group. A reactive response to fetal acoustic stimulation was associated with high specificity and negative predictive values. Therefore we conclude that fetal acoustic stimulation in the early intraprtum period may discriminate the compromised from the noncompromised fetus.     

Intrapartum amniotic fluid volume at term. Association of ruptured membranes, oligohydramnios and increased fetal risk

The amniotic fluid index (AFI), a semiquantitative technique for assessing amniotic fluid volume, has been shown to be a useful adjunct in antepartum surveillance. We evaluated the usefulness of the AFI in the early intrapartum period as it relates to subsequent fetal morbidity and fetal heart rate patterns. Two hundred term gravidas presenting in the latent phase of labor with vertex-presenting fetuses were studied. An intrapartum AFI less than or equal to 5.0 cm was associated with a significant increase in the risk of cesarean section for fetal distress and of an Apgar score of less than 7 at one minute as well as abnormal fetal heart rate patterns in late labor. The majority (71.4%) of the patients with an intrapartum AFI less than or equal to 5.0 cm had ruptured membranes on entry; however, there was no significant difference in outcome when they were compared to patients with intact membranes and oligohydramnios. Variable decelerations on entry were associated with oligohydramnios in 43.8% of the patients. An AFI less than or equal to 5.0 cm in the early intrapartum period is a risk factor for perinatal morbidity and abnormal fetal heart rate patterns in subsequent labor, and ruptured membranes in early labor are a risk factor for oligohydramnios.     

Computerized analysis of fetal heart rate variability using the matching pursuit technique as an indicator of fetal hypoxia during labor.

OBJECTIVE: To determine whether the computerized analysis of fetal heart rate variability with the new matching pursuit technique can indicate fetal distress during labor. STUDY DESIGN: Eighty women were studied during the intrapartum period with external cardiotocography. In all cases, cord arterial pH and 5-min Apgar Scores were evaluated. Six cases that presented large segments of missing data were excluded from the study. The remaining 74 women were divided into two groups; 32 women with normal (Group A) and 42 women with non-reassuring FHR tracings (group B). Group B was divided in subgroup BI, including 24 women with pH > 7.20, and BII, including 18 women with pH < 7.20. In order to evaluate the FHR fluctuations, in different frequency ranges, we applied an adaptive time-frequency method, called Matching Pursuit. We estimated the power of the FHR signal in four frequency ranges. RESULTS: The 5-min Apgar Scores were significantly lower in both subgroup BI and subgroup BII (p = 0.003 and p = 0.003 respectively). The Low Low Frequency (LLF) parameter appears to recognize better the cases with lower pH (sensitivity 78.5%, specificity 52.3%) than the cases with non-reassuring FHR (66.6%, 56.2). The sensitivity and specificity of the Very Low Frequency (VLF) parameter were 72.2% and 59% respectively in recognizing the cases with lower pH and 64.2% and 53.1% in recognizing non-reassuring FHR. CONCLUSION: Fetal hypoxia during labor can be recognized using the MP technique for the analysis of FHR signal power in the VLF and LLF frequency ranges. Since the analysis is feasible in real-time, it can be a useful tool for the intrapartum evaluation of fetal well-being.     

Meconium aspiration and fetal acidosis

Meconium in labor is associated with increased perinatal morbidity and mortality. To identify the infants at risk, 53 women with moderate-to-thick meconium were followed in labor after obtaining baseline fetal scalp blood pH levels. Although 28 of the newborns (53%) exhibited an arterial cord pH of less than 7.25 at delivery, there were no significant predictive variables found in the electronic fetal monitoring score, Apgar score, or mode of delivery. Nine of the infants with a pH value of less than 7.25 had meconium below the vocal cords at delivery, but none in the infants with pH levels greater than or equal to 7.25. The P50 value for cumulative acidosis is 55 minutes, indicating a more rapid deterioration than an average-for-gestational-age fetus without meconium. Therefore, the presence of thick meconium implies that fetal stress must be avoided during labor, and early intervention is warranted when there is deviation from normal labor progress or fetal heart rate pattern.     

脐血乳酸水平及胎心监护图形预测胎儿窘迫的价值

目的　探讨新生儿脐动脉血乳酸水平及胎心监护图形预测胎儿窘迫的价值。方法　测定 73例胎心监护图形为不良图形 (胎心基线异常、重度变异减速、轻度变异减速、心动过速 )的新生儿(病例组 )和 118例产前无胎儿窘迫征象 ,出生后 1分钟Apgar评分≥ 9分的新生儿 (对照组 )出生后脐动脉血乳酸水平。结果　病例组中产钳助产率明显高于对照组 (P <0 0 1) ,顺产率低于对照组 (P<0 0 1)。病例组中 ,胎心重度变异减速多发于第二产程 ;胎心基线异常的新生儿Apgar评分≤ 7分的发生率高于重度变异减速、轻度变异减速、心动过速的新生儿 (P <0 0 5 )。病例组中 ,胎心基线异常者脐动脉血乳酸水平为 (4 5 5± 0 2 3 )mmol/L ;重度变异减速者为 (3 84± 0 40 )mmol/L ,出现以上两种图形的新生儿脐动脉血乳酸水平均明显高于对照组 (P <0 0 1)。轻度变异减速者脐动脉血乳酸水平为 (2 63± 0 3 2 )mmol/L ;心动过速者脐动脉血乳酸水平为 (2 5 5± 0 46)mmol/L。并且轻度变异减速与心动过速者脐动脉血乳酸水平与对照组比较 ,差异无显著性 (P >0 0 5 )。结论　测定新生儿脐动脉血乳酸水平是一种有效、准确的诊断胎儿窘迫的方法。胎心基线异常、重度变异减速与胎儿窘迫的发生密切相关 ;轻度变异减速、心动过速与胎     

Labor induction versus expectant management for postterm pregnancies: a systematic review with meta-analysis

OBJECTIVE: To compare routine labor induction with expectant management for patients who reach or exceed 41 weeks' gestation. DATA SOURCES: Computerized databases, references in published studies, and textbook chapters in all languages were used to identify randomized controlled trials (RCTs) evaluating induction and expectant management of labor for postterm pregnancies. METHODS OF STUDY SELECTION: We identified RCTs that compared induction and expectant management for uncomplicated, singleton, live pregnancies of at least 41 weeks' gestation and evaluated at least one of the following: perinatal mortality, mode of delivery, meconium-stained fluid, meconium aspiration syndrome, meconium below the cords, fetal heart rate (FHR) abnormalities during labor, cesarean deliveries for FHR abnormalities, abnormal Apgar scores, and neonatal intensive care unit (NICU) admissions. The primary outcomes assessed were cesarean delivery rate and perinatal mortality. TABULATION, INTEGRATION, AND RESULTS: Sixteen studies met inclusion criteria for this review. For each study with binary outcomes, an odds ratio (OR) with 95% confidence intervals (CIs) was calculated for selected outcomes. Estimates of ORs for dichotomous outcomes were calculated using fixed and random-effects models. Homogeneity was tested across the studies. Compared with women allocated to expectant management, those who underwent labor induction had lower cesarean delivery rates (20.1% versus 22.0%) (OR 0.88; 95% CI 0.78, 0.99). Although subjects whose labor was induced experienced a lower perinatal mortality rate (0.09% versus 0.33%) (OR 0.41; 95% CI 0.14, 1.18), this difference was not statistically significant. Similarly, no significant differences were noted for NICU admission rates, meconium aspiration, meconium below the cords, or abnormal Apgar scores. CONCLUSION: A policy of labor induction at 41 weeks' gestation for otherwise uncomplicated singleton pregnancies reduces cesarean delivery rates without compromising perinatal outcomes.     

Fetal heart rate variability: an approach to automated assessment.

Three hundred seventy-five hours of fetal heart rate (FHR) data derived from the direct fetal electrocardiogram (ECG) were studied. This data had been stored on magnetic tape from 83 intrapartum patients. By means of a computerized technique, the FHR variability was assessed quantitatively. The degree of variability was then related to: (1) state of labor, (2) fetal scalp pH values, and (3) the 1-minute Apgar score. FHR variability was computed from differences between consecutive R-R intervals measured from the R wave of each fetal ECG. A trend of increasing variability was seen with advancing labor, defined by either time prior to delivery or cervical dilatation, but values were not statistically significant. Significantly less FHR variability was encountered when fetal scalp pH values below 7.20 were compared to higher values. FHR variability assessed during the 20 minutes immediately preceding delivery was significantly lower in infants with 1-minute Apgar scores less than 7. Machine assessment of FHR variability thus could be correlated with fetal condition as determined by scalp pH and neonatal outcome determined by Apgar score.     

第一产程异常胎心监护图形与新生儿结局的关系

目的　探讨第一产程异常胎心监护图形与新生儿结局的关系。方法　回顾分析 2 0 0 2年 8月至 2 0 0 3年 6月在我院足月单胎头位分娩产妇 ,第一产程中胎心率 (FHR)异常图形 2 1 7例 (观察组 )和FHR正常图形的2 6 9例 (对照组 )的临床资料。结果　第一产程异常FHR图形的发生率为 4 4 7% ,常见类型为轻度变异减速(6 4 5 % )、基线变异减弱 (2 1 6 % )和轻度心动过速 (1 2 0 % )。晚期减速、基线变异减弱和重度变异减速是导致新生儿窒息的危险因素。观察组羊水过少 (5 1 % )、脐带缠绕 (2 2 6 % )、羊水粪染 (1 0 6 % )、新生儿窒息 (6 5 % )、新生儿转入NICU(1 0 1 % )的发生率和剖宫产率 (31 8% )明显高于对照组 (P <0 0 5 )。结论　第一产程异常FHR图形的发生率较高 ,其中晚期减速、基线变异减弱、重度变异减速与新生儿窒息的发生相关 ,其他图形可在严密监护下继续试产     

Fetal pulse oximetry and wavelet analysis of the fetal heart rate in the evaluation of abnormal cardiotocography tracings

AIM: Previous studies indicate that the addition of wavelet analysis of the fetal pulse oximetry tracings (FSPO2) and fetal heart rate (FHR) variability to cardiotocography (CTG), for intrapartum fetal monitoring, provides useful information on the fetal response to hypoxia. We applied the new procedure in non-reassuring CTG patterns, in which cesarean section was performed, and tested its accuracy in the diagnosis of the intrapartum fetal compromise. METHODS: At the 'Aretaieion' University Hospital labor ward, 318 women with term fetuses in the cephalic presentation entered the trial during labor. They all were monitored with external CTG and fetal pulse oximetry. In the cases that cesarean section was applied, because of abnormal CTG tracings, we applied a method based on the multiresolution wavelet analysis and a self-organized map neural network on the first and second stage of labor. The main outcome parameter was the rate of cord metabolic acidosis at birth (pH < 7.05). Secondary outcomes included Apgar scores at 5 min, fetal transmission to neonatal intensive care unit (NICU) and neonatal encephalopathy. RESULTS: Fifty out of 318 cases delivered operatively because of abnormal CTG patterns (rate 15.72%). In 30 cases, cord pH was >7.05, while in 11 Apgar scores at 5 min were <7, while none of those neonates were transferred to NICU. In the rest 20 cases cord pH was <7.05; in all of these cases Apgar scores at 5 min were <7, while four neonates were transferred to NICU. In one of them, neonatal encephalopathy was diagnosed. After the offline application of wavelet analysis and neural networks to the pulse oximetry and FHR variability readings of the 50 cases, statistics calculated that the system showed a sensitivity of 85% and a specificity of 93%, while false negative and false positive rates were 15% and 7%, respectively. CONCLUSION: Computerized FHR and FSPO2 monitoring shows an excellent efficacy and reliability in interpreting non-reassuring FHR recordings.     

Four-quadrant assessment of amniotic fluid volume: distribution's role in predicting fetal outcome.

OBJECTIVE: The amniotic fluid (AF) index has been shown to be a useful tool in the area of antepartum surveillance. An intrapartum AF index less than or equal to 5.0 has been shown to have predictive value with respect to increased perinatal morbidity. This study was designed to determine whether the distribution of the AF within the AF index is related to perinatal outcome. METHODS: Patients presenting for labor and delivery had an AF index determined and were divided into two groups. Patients with greater than 50% of their AF distributed in the upper quadrants were placed in the "upper-greater" group. The remaining patients were placed in the "lower-greater" group. The distribution data were compared with the following variables: meconium staining, 1- or 5-minute Apgar score of less than 7, persistent variable decelerations in the first stage of labor, late decelerations, neonatal intensive care unit admission, cesarean delivery for fetal distress, and umbilical arterial and venous pH less than 7.20. RESULTS: A total of 218 patients were evaluated, 125 in the upper-greater group and 93 in the lower-greater group. The upper-greater group had a greater incidence of meconium staining (32.8 versus 9.7%; P < .0001), 1-minute Apgar score of less than 7 (12.0 versus 2.2%; P < .007), variable decelerations (53.6 versus 19.4%; P < .00001), late decelerations (16.0 versus 0%; P < .0001), cesarean delivery for fetal distress (7.2 versus 0%; P < .008), umbilical arterial pH less than 7.20 (29.6 versus 8.9%; P < .0105), and umbilical venous pH less than 7.20 (8.9 versus 0%; P < .0398). These results were maintained regardless of the overall AF index. CONCLUSIONS: The distribution of the fluid within the AF index is predictive of perinatal outcome. In addition, the presence of a high negative predictive value for all of the perinatal indices studied enhances the value of this technique as a potential screening tool. Application of these results could provide additional guidelines in defining the intrapartum management and therapy of patients presenting for labor and delivery.     

A new computerized analysis to precisely evaluate heart rate variability during the nonstress test

The study was conducted to assess whether the power spectrum analysis of fetal heart rate (FHR) data obtained with a cardiotocograph provides more than visual judgment of nonstress test (NST) tracing to predict fetal well-being. A total of 71 FHR data were obtained from 44 healthy pregnant women with normally grown fetuses and 11 pregnant women with pregnancy-induced hypertension. Power spectrum analysis was performed for the 8192 points of the instantaneous heart rates derived from these FHR data. Abnormal perinatal outcome was defined when at least one of the followings were present at birth: Cesarean delivery for nonreassuring FHR pattern and umbilical artery cord PH < or = 7.15, delivery at < or = 32 weeks for fetal compromise, neonatal seizures within the first 72 hours of life, respiratory distress at 36 weeks or more, 5-minute Apgar score < 7 and stillbirth. The total power of the 8192 points without considering gestational weeks was 256.3 +/- 65.6 normalized units (NU) . Hz in the fetuses with good outcomes (n = 47), while that of the abnormal fetuses (n = 8) was 148.5 +/- 54.6 NU . Hz. There is a significant difference between the two values (p < 0.00001). When the abnormal value of the total power of the 8192 points was defined as < 200 NU . Hz, the sensitivity on the prediction of fetal outcome using this method was 81.8%, significantly higher than that of the nonstress test tracing (p < 0.05). The power spectrum analysis of the large amount of FHR data obtained with a cardiotocograph permits a better assessment of the fetal well-being and may be suitable for the screening test because of no additional manpower to the current NST.     

Management of prolonged pregnancy: results of a prospective randomized trial.

Prolonged pregnancy was rigorously defined in 180 gravid women without other complications. Patients were randomly assigned to be serially followed, either by amniocenteses or by oxytocin challenge tests (OCT's). Induction of labor, based upon only (1) a finding of meconium in the amniocentesis group or (2) a positive test in the OCT group, was nearly three times more frequent in the amniocentesis group. The incidence of meconium, which overall was 22% initially and 44% at delivery, as well as the frequencies of obstetric and perinatal complications, were similar in both management groups. Although meconium was significantly associated with abnormal labor progression, intrapartum fetal distress, and low 1 and 5 minute Apgar scores, induction of labor after discovery of meconium, when compared to nonintervention, did not improve perinatal outcome. It is concluded that a search for meconium is of little value in the management of prolonged pregnancy.