Human fetal movement: spontaneous oscillations near one cycle per minute.

Spectral analysis of spontaneous fluctuations in human fetal movement revealed strong oscillations at frequencies between 0.24 and 0.90 cycle per minute, which are much higher than those of the cyclic alternation of quiet and active states in the fetus and neonate. Oscillations at frequencies up to 2.88 cycles per minute were also detected, but they were usually much weaker. The prominent peaks in the fetal movement spectra are in the frequency range of recently reported neonatal motor rhythms, and indicate the existence of a cyclic process controlling spontaneous motor output that oscillates near one cycle per minute and begins to function in utero.

Gestational diabetes mellitus. Is further improvement necessary?

The maternal antepartum, intrapartum, and neonatal characteristics of 158 patients with gestational diabetes mellitus (GDM) attending a large teaching hospital between 1979 and 1983 were described and compared with a matched nondiabetic control group. The primary cesarean section rate in patients with GDM (18%) was significantly greater than in the control group (11%, P less than 0.04). Neonatal macrosomia, as reflected in mean birthweight (P less than 0.04), the number of neonates weighing greater than 4 kg (P less than 0.05) and large-for-gestational-age infants (P less than 0.05), and the birthweight adjusted for gestational age (K-score, P less than 0.01) was significantly increased in the diabetic group. The characteristics of patients with GDM treated with diet alone and diet and insulin together were examined. The insulin-therapy group was characterized by more patients older than 25 yr (P less than 0.01) and a higher mean birthweight (3743 +/- 677 g) (P less than 0.02) than the diet-alone group. This may reflect an increased magnitude of glucose intolerance in the insulin-treated group. Obese patients with GDM delivered heavier neonates than the nonobese patients with GDM (P less than 0.01). Although there was no difference between the groups, perinatal mortality was present in this study. These data indicate that the major perinatal morbidity in GDM included increased cesarean section for fetal macrosomia. Early diagnosis with strict diagnostic criteria and rigid antenatal surveillance may result in further improvements in outcome.

Effect of amniotic membrane rupture on length of labor.

Between January 1, 1979, and December 21, 1982, 2564 medically and obstetrically normal patients, admitted to the hospital with intact amniotic membranes during the latent phase of labor, were matched for spontaneous or artificial rupture of the membranes at similar cervical dilations. Spontaneous rupture of the membranes occurred earlier and was more likely in the latent phase of labor than was artificial rupture of membranes, which tended to occur nearer to or in the active phase of labor, and at lower pelvic stations. When matched by cervical dilation, spontaneous membrane rupture was associated with more rapid cervical dilation. Stepwise regression analysis confirmed that membrane rupture had a significant but small effect on labor length and rate of cervical dilation. Pelvic station and maternal parity had a smaller association with labor length than did membrane rupture. Cervical dilation at the time of membrane rupture appeared to be the most important factor associated with the length of labor.

Prenatal and perinatal factors associated with brain disorders.

In April 1985, a report entitled "Prenatal and Perinatal Factors Associated with Brain Disorders" was published by the National Institutes of Child Health and Human Development and the National Institute of Neurological and Communicative Disorders and Stroke. A panel of ten individuals completed the report documenting the knowledge and the complexities of what is known with respect to brain damage that may develop before birth or in the neonatal period. It is clear that all stages of fetal and neonatal development influence normal outcome. Although intrapartal period events may explain a significant portion of cerebral palsy, the illness is often linked with confounding factors such as low birth weight and asphyxia. Pure epilepsy or pure mental retardation is rarely associated with intrapartal events. In general, the pathologic lesions seen in the brain may reflect many different fetal insults. The same clinical event such as asphyxia may result in varied intracranial diseases, which effects may depend on when the clinical events occurred.

Transition from latent to active labor.

The transition from the latent to the active phase of labor, as defined by Friedman, was studied in all noncomplicated patients over a four-year period. Mothers studied were in spontaneous labor with a singleton fetus in the vertex position with intact membranes at admission. The independent variables were the parity and vaginal examination data, and the dependent variable was the rate of cervical dilation. The transition from latent to active labor was recorded and stratified by the cervical dilation where it occurred in a sample population consisting of 1060 nulliparous and 639 primiparous or multiparous women. There were no differences between nulliparous and multiparous patients. Less than 50% of labors became active by the time the cervixes had reached 4-cm dilation. By 5 cm, 74% of labors were active. However, when protracted and arrested labors were eliminated, 60% of the patients had reached the latent-active transition by 4 cm and 89% by 5 cm. We concluded that once a normal patient has reached 5 cm, she should be in the active phase of labor. If not, there is a high probability of labor dystocia.

Cervical incompetence: diagnosis and outcome.

The results of 147 cervical cerclage procedures were reviewed in a retrospective study. Patient history and past reproductive performance were assessed to determine which factors were predictive of successful pregnancy outcome after cervical cerclage. A past history of spontaneous second trimester abortion or premature labor was associated with a better outcome than was a history classically associated with cervical incompetence. Morbidity immediately following the procedure was low, however significant morbidity related to cervical scarring occurred at the time of delivery. There was poor correlation between the clinical history, examination and adjunctive tests of cervical incompetence, and the pregnancy outcome following cerclage. These observations indicate the need for a prospective, randomized study of the efficacy of this procedure.

Vaginal birth after cesarean: a meta-analysis of indicators for success.

The cesarean birth rate has continued to climb despite efforts to counteract this trend. A major reason for this rise is the practice of doing an elective repeat cesarean. Our study used a statistical model of meta-analysis to analyze the findings of 29 individual studies that looked at the association between the success of a trial of labor and various preexisting conditions. We hypothesized that various preexisting factors, including cephalopelvic disproportion, previous breech, previous vaginal delivery, more than one previous cesarean, use of oxytocin, and the length of labor and extent of dilatation in the previous cesarean, would affect the prediction of the outcome of a trial of labor. After determining odds ratios for the individual preexisting factors from the individual studies, we calculated overall odds ratios which incorporated the findings from all of the studies. For previous cephalopelvic disproportion, the odds were 0.5 for a successful trial of labor; for prior breech, 2.1; for women with a previous vaginal delivery, 2.1; for women who had had more than one cesarean, 0.7; and for women receiving oxytocin, 0.3. We were unable to analyze other preexisting factors because the data were not available, but short discussions of some of these other factors are offered. Even though the success rates do vary with the different preexisting factors, the clinician may anticipate a greater than 50% chance for success in any individual labor.

Latent phase of labor in normal patients: a reassessment.

The vaginal examination data (dilation, station, and time) were examined from 2845 consecutive uncomplicated patients who were admitted in early labor to Cleveland Metropolitan General Hospital between January 1, 1979 and December 31, 1982, using data from the computer database of the Perinatal Clinical Research Center. The length of the latent phase of labor was calculated in 2479 of these patients to form the study group. Individual effects of parity and the cervical dilation on the length of the latent phase of labor resembled Friedman's results from 20 years ago. Furthermore, the average and prolonged lengths of the latent phase confirmed that labors have not changed appreciably in 20 years. However, multivariable analysis and standard stepwise regression on all of the vaginal examination data revealed that the largest influence on the length of latent labor was the admitting cervical dilation. Parity had only a small effect when cervical dilation was controlled. Thus, a multiparous patient may progress as slowly as a primiparous patient if they both are admitted with a low cervical dilation.

"Prediction" of the one-minute Apgar score from fetal heart rate data.

The value of any fetal monitoring technic is in its ability to predict infant outcome. In the present study, the ability of fetal heart rate (FHR) monitoring data to "predict" a measure of short-term infant outcome, the 1-minute Apgar score, was evaluated using univariate and multivariate statistical analyses. Of 61 monitored high-risk infants, 46 had high (7 to 10) and 15 had low (1 to 6) 1-minute Apgar scores. Computer analysis of FHR/intrauterine pressure (IUP) data for these 61 infants revealed that the infants with low Apgar scores had more than the expected number of late decelerations (LD). Using a threshold of ten LD and univariate analysis, 74% of the infants could be properly classified for high or low Apgar scores, but 60% of the infants with low Apgar scores were not identified. Using discriminant function (multivariate) analysis for the numbers of LD and uterine contractions, 47% of the depressed infants were appropriately identified and simple risk scoring equations were devised. Using additional observation vectors, including the number of accelerations and early decelerations, 67% of the depressed infants could be identified. The results of this study suggest that using multiple observation vectors improves the predictive capacity and, thus, the value of fetal monitoring data. Clinical experience suggests that the value of monitoring data can be further enhanced by simultaneous evaluation of other observation vectors from additional perinatal data sets using the technics of this study.

Arrest disorders and infant brain damage.

In the past, difficult labors have been associated with maternal and infant damage. Today, changing patient management is associated with less trauma and more frequent use of cesarean births to avoid potential fetal neurologic damage. In this report, arrests of dilatation and descent and prolongation of the decelerative phase of labor were reviewed with respect to the later appearance of brain damage in infants after 2 years of age, in association with obstetric interventions including cesarean birth, forceps, and oxytocin. Charts of 413 infants born after abnormal labors were studied. Log-linear analysis was performed to determine the contribution of method of delivery and oxytocin use to the presence of neurologic abnormalities. Statistical testing ruled out the presence in the model of a three-way interaction, and excluded the two-way interactions of neurologic abnormalities-oxytocin use and neurologic abnormalities-method of delivery. Chi-square tests of partial association and marginal association for the delivery-oxytocin interaction yielded values of 33.54 (P less than .0001) and 33.78 (P less than .00001). This model asserted that method of delivery and use of oxytocin were unrelated to the presence of neurologic abnormalities, but were related to each other.

Caring for our future: a report by the expert panel on the content of prenatal care.

The report of the Expert Panel on Prenatal Care entitled Caring for Our Future: The Content of Prenatal Care was presented to the Assistant Secretary for Health, James Mason, MD, on October 2, 1989. The Panel noted the need for attention not only to the mother and fetus, but also to the infant and family. Besides traditional medical care concerns, the importance of psychosocial and environmental patient and family needs was emphasized. The Panel felt that the addition of the pre-conception visit to routine prenatal care made care more effective. Suggestions as to visit timing and content were made. The Panel noted the need for further understanding of many of the activities performed routinely in prenatal care.

Abnormal labor and infant brain damage.

OBJECTIVE: To determine whether arrest disorders result in increased neurologic abnormalities in infancy or childhood. METHODS: Four hundred thirteen infants with arrest disorders as defined by Friedman criteria were matched to a similar population without arrest disorders. The median length of follow-up was 6 years for the study infants and 5.07 years for the controls. The numbers of children with abnormalities in the groups with and without arrest disorders, as well as the specific abnormalities encountered, were stratified by method of delivery. RESULTS: Thirty neurologic abnormalities were found in the arrest group and 37 in the control group; thus, the null hypotheses could not be rejected. In addition, although the control group was not followed as long as the study population, the diagnosis of abnormalities was more frequent in the later years in the controls. This suggests that had the follow-ups been equal, there would have been stronger proof that arrest by itself was not associated with infant brain damage. CONCLUSION: Our study confirms that labor diagnoses of prolonged active phase, protractions or arrests, and failure to descend are not associated with increased neurologic abnormalities. Delivery by cesarean or vaginal birth and use of oxytocin are not factors in the etiology of major brain damage.

Risks preceding increased primary cesarean birth rates.

Recent increases in cesarean birth rates are of concern to obstetricians and to the public. Previous studies often focused on indications for abdominal delivery, described in such broad categories as repeat cesarean, breech presentation, dystocia, and fetal distress, without detailed information concerning medical/obstetric risk factors. In this study of 2744 consecutively delivered mothers who received antenatal care, the problem was approached differently by evaluating approximately 100 pregnancy risk factors recorded in a computerized uniform perinatal record system before making a decision for delivery. Excluding repeat cesareans, relative risks for primary cesarean birth were calculated for each risk factor. For the large majority of patients, the need for primary cesarean birth could not be predicted before the onset of labor. Approximately 70% of primary cesareans could be accounted for on the basis of single pregnancy risks--antepartum problems, 11%; abnormal fetal presentation, 30%; abnormal labor, 14%, and fetal distress, 15%. This leaves 30% of primary cesareans without a single major preceding risk. Along with the facts that 80% of primary cesareans in this series were performed for normal-size infants and that dystocia appears to account for a 3.4-fold greater proportion of cesareans in the national experience than in the current study, this suggests that critical evaluation and study of obstetric management of dystocia may be most fruitful in responding to the question of rising cesarean birth rates.

Active and quiet periods in the preterm and term fetus.

Heart rate variability and fetal movement were used to classify active and quiet fetal periods. Fetuses at 28 to 30 weeks and at 38 to 40 weeks' gestation were compared. A period of fetal movement with increased variability of heart beat was classified as active and one with the absence of movement and diminished fetal heart beat was classified as quiet. The results demonstrated significant differences both in the number of active-quiet cycles per hour and in the length of the active periods. These findings suggest that analogs of fetal behavioral states may be present before birth and have cyclic patterns, and that the time spent in each fetal period is longer in older fetuses.

Risk, antepartum care, and outcome: impact of a maternity and infant care project.

A Title V Maternity and Infant Care (M&I) Project has been operating from Cleveland Metropolitan General Hospital for more than 13 years. To evaluate the effectiveness of its program of antepartum care, social and medical-obstetric risk factors and perinatal outcome were evaluated for pregnant women delivered during a 2-year period. After the potential biases of patient referral and failure to obtain antepartum care were excluded, patients who received either M&I or non-M&I care were compared. Despite the similar social and antepartum/intrapartum risk of these groups, the M&I patients experienced 60% less perinatal mortality than the non-M&I group (P less than .0001). These results suggest that M&I antepartum care is of considerable value, possibly ameliorating the risks for preterm delivery. M&I patients receive more patient education, nutrition counseling, social service assessment and intervention, special services for adolescents, and delinquent appointment follow-up. Thus, this study further suggests that these components of antepartum care may be important in producing the observed improvement in fetal-infant outcome.

Efficacy and safety of Laminaria digitata for preinduction ripening of the cervix.

Twenty-five study patients in whom laminaria tents had been used for the preinduction ripening of the cervix were compared with 28 control patients in a retrospective study. Both groups had comparable indications for induction, parity, mean maternal age, mean birth weight, and gestational age. Although laminaria appeared to be effective in reducing the duration of induction, no difference in the incidence of cesarean birth was apparent between the laminaria and nonlaminaria groups. Maternal endometritis was present in 15 of 25 mothers in the laminaria group, and in 3 of 28 in the control group (P less than .05). All 9 mothers who had cesarean deliveries in the study group had endometritis, whereas it occurred in only 3 of 11 in the control group (P less than .005). Six of the 16 patients in the study group who delivered vaginally had endometritis, whereas none of 17 in the control groups has it (P less than .01). Five of 25 neonates in the study group has sepsis, but there was no evidence of sepsis in the 28 control neonates (P less than .05). Three of the 5 septic neonates died. There were no neonatal deaths in the control group. The findings suggest that laminaria use in associated with significant risk of maternal and neonatal infectious morbidity.

Vaginal birth after cesarean: a meta-analysis of morbidity and mortality.

The cesarean birth rate has continued to climb despite efforts to counteract it. A major reason for this rise is the practice of elective repeat cesarean. We conducted a meta-analysis that included 31 studies with a total of 11,417 trials of labor to evaluate the association between birth route after a cesarean and morbidity and mortality for the mother and infant. Summary odds ratios were calculated. Maternal febrile morbidity was significantly lower after a trial of labor than after an elective repeat cesarean. The intended birth route made no difference in the rates of uterine dehiscence or rupture. The use of oxytocin, presence of a recurrent indication for the previous cesarean, and presence of an unknown uterine scar were also unassociated with dehiscence or rupture. After excluding antepartum deaths, fetuses weighing less than 750 g, and congenital anomalies incompatible with life, we found no difference in perinatal death rates. The proportion of 5-minute Apgar scores of 6 or lower was higher after a trial of labor, but we were unable to exclude very low birth weight fetuses or those with congenital anomalies from this analysis. Our findings argue for trials of labor for more women after a cesarean birth.

Maternal and fetal plasma concentrations of ritodrine.

Previous studies using other beta-adrenergic drugs for tocolysis suggest that if treatment fails and the patient delivers shortly after the therapy is discontinued, there is a direct correlation between neonatal drug concentration and major neonatal complications. In the present study, the disposition of ritodrine was studied in 28 maternal-infant pairs in whom intravenous ritodrine had been administered for clinical indications. The fetal to maternal ratio of ritodrine was 1.17 +/- 0.48. The concentration of ritodrine in both maternal and umbilical vein was found to vary inversely with the length of time the drug was discontinued before delivery. A stepwise multilinear regression revealed that the maternal ritodrine dose in the 24 hours before delivery and the drug discontinuance to delivery interval were both independently related to umbilical vein ritodrine concentrations. When combined, the two variables explained 52% of the variance in umbilical vein ritodrine levels. The frequency of respiratory distress syndrome was increased in the neonates in whom umbilical vein ritodrine was greater than 10 ng/mL, compared with the groups with umbilical vein levels ranging from 3.0 to 10.0 ng/mL. However, neonates with the highest ritodrine concentration were also of lower gestational age (29.4 versus 33.5 weeks, P less than .05) and thus, had greater inherent risk of prematurity-related complications.

Obstetric care and cesarean birth rates: a program to monitor quality of care.

OBJECTIVE: To study the quality of obstetric care in relation to rising cesarean rates, a Task Force was formed in New York state by the Department of Health and ACOG District II. The Task Force also included the Organization of Obstetric, Gynecologic, and Neonatal Nurses and the Hospital Association of New York State. The goals were to enhance hospitals' in-house review processes, standardize terminology, and improve the quality of care. A premise of the program was that if quality of care improved, cesarean rates would fall. METHODS: A Dictionary of Terms was developed to standardize clinical and diagnostic terminology. A two-tiered review process was instituted, using internal and external hospital reviews. A format for in-house review of obstetric care was developed and recommended to hospitals. External reviews were conducted at 24 hospitals during 1989-1990. Review teams, composed of obstetrician-gynecologists and obstetric nurses in active obstetric practice, assessed obstetric facilities, staffing, medical care, and the in-house review process. Contacts continued with the hospitals after site visits to follow up on implementation of recommendations. General recommendations to improve care, based on the overall program experience, were distributed to hospitals and physicians as part of educational efforts to improve quality of care. RESULTS: The state cesarean rate reversed. Statistics for 1989 and 1990 showed a stronger downward trend in reviewed hospitals than in non-reviewed hospitals. A survey of reviewed hospitals reported a positive response to the review process. CONCLUSION: A successful quality assurance program can be jointly developed by a state regulatory agency and a medical specialty society.

Regular and irregular human fetal respiratory movement.

Fetal respiratory movements (FRM) were studied using abdominal strain gauges (tocodynamometers). The patterns of the FRM were evaluated during both active and quiet fetal time periods, which were determined by the fetal heart rate (FHR) and fetal body movement (FM). The FRM were classified into Regular and Irregular patterns based on neonatal respiratory criteria for sleep-state studies in the term infant. Evaluation of the breath-to-breath intervals (BBI) showed statistically significant respiratory differences during active and quiet fetal time periods. Irregular fetal respiratory movement patterns were noted during fetal active periods. It would appear that the correlation of regular fetal respiratory movement with fetal quiet periods in the term fetus adds additional evidence that a quiet sleep state may exist in the term fetus.