Middle cerebral artery blood flow velocity in the newborn following delivery.

Ninety-five normally grown term and preterm newborns were examined to determine the means and prediction limits of cerebral blood flow velocity following delivery and to examine the relationship of systemic blood pressure to cerebral blood flow velocity. Doppler blood flow velocity was observed during the four days following delivery. Continuous measures of blood pressure and heart rate were recorded concurrently. Mean peak systolic and end diastolic blood flow velocity immediately following delivery was 43.2 and 9.3 cm/sec for term newborn, and 31.8 and 3.3 cm/sec for preterm newborn. During the 24 h following delivery there was no change of peak systolic blood flow velocity but a two to three fold increase of end diastolic blood flow velocity in the term and preterm newborn. The reference limits for peak systolic and end diastolic blood flow velocity provide criteria to define abnormal increases and decreases of blood flow velocity. During the 24 h following delivery, increasing diastolic blood pressure was associated with increasing end diastolic blood flow velocity independent of birth weight and time following delivery. Also there was a significant correlation between systemic pressure pulsatile index and middle cerebral artery blood flow velocity pulsatile index. Thus systemic blood pressure pulsatility must be recognized as distinct from other intracerebral influences on cerebral blood flow velocity regulation in the newborn.

Mortality and morbidity after intrapartum asphyxia in the preterm fetus.

This matched cohort study examined the significance of intrapartum fetal asphyxia determined biochemically in the preterm newborn in regard to outcome during the first year. Thirty preterm newborns with metabolic acidosis at delivery were compared with 60 preterm newborns, matched for birth weight, with normal blood gas measures. Deaths during the first year were reviewed. Assessment of the surviving children at 1 year corrected age included neurologic examination, Bayley scales, and Uzgiris and Hunt scale to define motor and cognitive development. Seven asphyxiated infants (23%) died during the first year compared with two nonasphyxiated infants (3%), a statistically significant difference (P less than .006). Among the surviving children, the incidence of minor motor and/or cognitive deficits was the same in the two groups. The incidence of major motor and/or cognitive deficits in the group with asphyxia (eight of 30) was significantly greater than in the control group (eight of 60) (P less than .03). These results indicate that intrapartum fetal asphyxia in the preterm newborn is a contributing factor to the mortality and morbidity observed in these children.

Hypotension and hypoxemia in the preterm newborn during the four days following delivery identify infants at risk of echosonographically demonstrable cerebral lesions.

This prospective study of 130 preterm newborns at less than 34 weeks gestational age has examined the predictive value of abnormalities in continuously recorded newborn blood pressure, heart rate, and oxygen tension during the 4 d following delivery for echosonographically demonstrable cerebral lesions (EDCL) identified in the infant by six months corrected age. EDCL consisting of intraventricular hemorrhage, ventriculomegaly, or hyperechoic parenchymal lesions in the brain were identified in 44 preterm newborns (34%). The incidence of EDCL in preterm newborns with no hypotension or hypoxemia was 13%. The incidence of EDCL was significantly increased in preterm newborns with either hypotension or hypoxemia. The probability of EDCL exceeded 50% when the total exposure to either hypotension or hypoxemia during the 4 d exceeded 50 mmHg-hours, or when newborn hypotension and hypoxemia occurred concurrently. No relationship to hypertension, bradycardia, or tachycardia was detected. These findings indicate that hypotension and hypoxemia in the preterm newborn during the 4 d following delivery are useful risk markers of EDCL.

Blood pressure and heart rate of the preterm newborn following delivery.

Thirty-five preterm newborns were studied to determine the mean blood pressure and heart rate of preterm newborns less than 1500 gm and greater than or equal to 1500 gm at birth. Systemic blood pressure increased and heart rate decreased with increasing maturity at birth. Both systemic blood pressure and heart rate increased during the four days following delivery. The 95% prediction limits of stable preterm newborns less than 1500 gm and greater than or equal to 1500 gm at birth are useful criteria to define hypertension and hypotension, as well as tachycardia and bradycardia.

The association of intrapartum asphyxia in the mature fetus with newborn behavior.

A matched cohort study of mature newborns with biochemically determined intrapartum fetal asphyxia and mature newborns with normal blood gas and acid-base assessments at delivery were studied to demonstrate the effect of fetal asphyxia on newborn behavior as expressed by the Brazelton newborn behavioral assessment scale. The newborn behavioral assessment scale was administered 3 days after delivery and again 2 weeks after delivery. The Lester newborn behavioral assessment scale summary scores for the group with asphyxia were of the same order as those in the control group. This was also true of the group of newborns with asphyxia with the more severe metabolic acidosis and those with low Apgar scores. These findings support the contention that many newborns who have undergone an intrapartum asphyxial insult will not have evidence of central nervous system injury and that the threshold of central nervous system injury is at the severe end of the spectrum of asphyxia as expressed by a metabolic acidosis.

The association of fetal and newborn metabolic acidosis with severe periventricular leukomalacia in the preterm newborn.

One hundred twenty preterm newborns less than 34 weeks' gestational age have been studied prospectively to determine the frequency of fetal and newborn metabolic acidosis and to examine the relationship of metabolic acidosis to periventricular leukomalacia as demonstrated by serial newborn ultrasonographic examinations. Fetal metabolic acidosis, based on an umbilical artery buffer base less than 34 mmol/L at delivery, occurred in three cases (2%), one of which had evidence of periventricular leukomalacia. Newborn metabolic acidosis that is based on a buffer base less than 34 mmol/L during the 4 days after delivery occurred in 12 cases (10%), five of which had evidence of periventricular leukomalacia. There is a significant relationship between the degree and duration of newborn metabolic acidosis and the occurrence of periventricular leukomalacia. This study indicates that systemic metabolic acidosis is an important pathophysiologic marker of periventricular leukomalacia. Intrapartum fetal asphyxia with metabolic acidosis, although an infrequent occurrence in the preterm newborn, may account for a few cases of periventricular leukomalacia, while the more common newborn metabolic acidosis, when of sufficient degree and duration, carries a high risk of periventricular leukomalacia.

Intrapartum asphyxia in the preterm fetus less than 2000 gm.

The incidence of intrapartum asphyxia in the preterm fetus less than 2000 gm (6%) is greater than that in the mature fetus (2%). Severe antepartum hemorrhage is the only clinical marker predictive of asphyxia in the preterm fetus. Marked deceleration patterns and particularly late decelerations may be of predictive value for asphyxia. However, many intrapartum asphyxial episodes are not identified on the basis of clinical observations. Consistent diagnosis of intrapartum asphyxia in the preterm fetus requires routine umbilical cord blood gas and acid-base assessment at delivery.

Motor and cognitive deficits after intrapartum asphyxia in the mature fetus.

The incidence of major and minor motor and/or cognitive deficits at 1 year of age, in 37 mature children who had experienced an intrapartum fetal asphyxial insult, was compared with the incidence of deficits at 1 year in 76 children of the control group. The incidence of both major and minor deficits was significantly greater in the group with intrapartum fetal asphyxia in relation to the control group. These findings support the concept that, beyond a critical threshold of fetal asphyxia, a continuum of casualty in the surviving newborn infants exists.

Motor and cognitive development of infants with intraventricular hemorrhage, ventriculomegaly, or periventricular parenchymal lesions.

Two hundred twenty-six moderate- or high-risk newborn infants were studied to examine the relationship between ultrasound findings in the newborn period and at 6 months and motor and cognitive deficits at 1 year. A three-part classification of abnormal ultrasound findings was used to grade intraventricular hemorrhage, ventriculomegaly, and parenchymal lesions. Abnormal ultrasound findings were observed in 48 infants, of whom 21 had intraventricular hemorrhage, 18 persistent ventriculomegaly, and nine parenchymal lesions. The incidence of deficits was as follows: normal ultrasound examination, 20%; intraventricular hemorrhage, 33%; persistent ventriculomegaly, 67%; and parenchymal lesions, 89%. The present study indicates that serial ultrasound examinations are indicated in preterm newborn infants less than 1500 gm and in selected newborn infants at risk and greater than 1500 gm at birth. The three-part classification of abnormal ultrasound findings should be used because of the predictive significance of persistent ventriculomegaly and parenchymal lesions for motor and cognitive deficits at 1 year of age.

The relationship between antepartum fetal heart rate, intrapartum fetal heart rate, and fetal acid-base status.

The relationships between antepartum baseline fetal heart rate, baseline variability, accelerations, decelerations, and fetal movement and intrapartum fetal heart rate, fetal acid-base assessment at delivery, and Apgar scores 1 and 5 minutes after delivery were studied in 290 mature pregnancies. There was a significant relationship between antepartum and intrapartum baseline fetal heart rate and baseline variability. There was no relationship between antepartum and intrapartum accelerations or decelerations. There was no correlation between antepartum fetal heart rate or fetal movement and fetal acid-base status at delivery or Apgar scores 1 and 5 minutes after delivery. There was a trend for decreased accelerations and decreased fetal movements to be associated with a low Apgar score 1 minute after delivery.

Cervical carcinoma in women aged 34 and younger.

This presentation addresses three questions concerning invasive cervical carcinoma in women 34 years of age and younger. Is there an increase in the incidence of the disease? Is it more or less susceptible to prevention by cervical screening? Is the clinical behavior different for this age group? Three separate studies are reported: (1) Incidence data in the younger age group have been reviewed at the national, provincial, and local levels. (2) Cytologic screening histories of 125 patients who subsequently developed cervical carcinoma were reviewed. (3) The clinical histories of 121 women 34 years of age and younger, with invasive cervical carcinoma, were reviewed and compared with those of 242 control women 35 years of age and older. Results indicate an increase in incidence in the younger age groups in the three prairie provinces only. Cytologic histories are similar except for an increase in false negative reports in the younger age group. Clinical behavior of the disease is similar for both age groups.

Maternal, fetal, and newborn complications associated with newborn intracranial hemorrhage.

Two hundred twenty newborn infants with one or more fetal or newborn complications and 54 newborn infants without fetal or newborn complications were prospectively studied to assess the relationship between maternal, obstetric, fetal, and newborn complications and intracranial hemorrhage. Intracranial hemorrhage occurred in 47 newborn infants with fetal or newborn complications (21%) and in one infant with no fetal or newborn complications (2%). Maternal and obstetric complications, duration of labor, and mode of delivery were not associated with intracranial hemorrhage. Newborn immaturity at delivery is an important factor in the occurrence of intracranial hemorrhage. There is little evidence that fetal hypoxia is a contributing factor. Severe respiratory complications and major infections are newborn complications associated with intracranial hemorrhage.

The contribution of fetal-newborn complications to motor and cognitive deficits.

A total of 364 selected high-risk premature and mature infants were studied prospectively to assess the relationship between fetal-newborn complications and motor and cognitive deficits identified during the first year of life. Deficits occurred in 24 per cent of the children: 14 per cent had one or more major deficit and the other 10 per cent had one or more minor deficit. Prematurity was one of the fetal-newborn complications not associated with deficits at one year. Complications that were associated with deficits included fetal hypoxia, respiratory difficulties, infection and newborn encephalopathy. There was also a significant association between fetal hypoxia, newborn respiratory complications, infection and newborn encephalopathy, which is in keeping with the concept that the first three may be mechanisms in CNS injury and subsequent deficits, while newborn encephalopathy reflects the injury and is an important predictor of such deficits.

The relationship between perinatal hypoxia and newborn encephalopathy.

Newborn encephalopathy was observed in 30% of 303 selected high-risk preterm and term newborn infants. The newborn encephalopathy was mild or moderate in 65 children and severe in 27. The predictive significance of newborn encephalopathy to motor and cognitive deficits at 1 year was evident from the incidence of deficits in the children with no encephalopathy (17%), in children with mild or moderate encephalopathy (25%), and in children with severe encephalopathy (55%). The biologic risk factors with a significant association with newborn encephalopathy included severe intrapartum fetal hypoxia, moderate and severe newborn respiratory complications, and major infections. Perinatal hypoxia was associated with, and may have contributed to, 26% of the cases of mild and moderate newborn encephalopathy and 66% of the cases of severe newborn encephalopathy. Fetal and newborn hypoxia occurred with equal frequencies in cases of mild and moderate encephalopathy; however, newborn hypoxia was twice as frequent as fetal hypoxia in cases of severe newborn encephalopathy.

Factors associated with motor and cognitive deficits in children after intrapartum fetal hypoxia.

Sixty children with biochemical evidence of intrapartum fetal hypoxia were studied to define the factors which distinguish the children with deficits from those without deficits of motor and cognitive development. Follow-up assessment included growth measures, neurological examination, Bayley Scales of Infant Development, and a modified Uzgiris and Hunt Scale. Eight children (13%) had a major deficit and 10 children (16%) had a minor deficit at 1 year. Children with deficits had an episode of hypoxia that was more severe and prolonged and, subsequent to delivery, a greater incidence of severe respiratory complications, apnea, and newborn encephalopathy. No other significant risk factors were identified. It is concluded that an episode of hypoxia less than one hour may occur without subsequent deficits. However, an episode of hypoxia in excess of 1 hour resulting in a metabolic acidosis of the order of 25 mEq/L will be followed by motor and cognitive deficits in approximately 50% of children.

The predictive significance of biologic risk factors for deficits in children of a high-risk population.

Two hundred forty-two high-risk children and 47 low-risk children were prospectively studied to assess the relationship between biologic risk factors that occurred during the perinatal period and the motor and cognitive deficits that were identified during the first year of life. Multiple risk factors were present in 80% of the children of the high-risk group. Provisional deficits were classified on the degree of abnormality found in a clinical and behavioral assessment that included neurological examinations, Bayley Physical and Mental Development Scales, and the Uzgiris and Hunt Scale. Provisional deficits occurred in 10% of the children of the low-risk group. High-risk children had a significantly greater incidence of provisional deficits, particularly in respect to positive deficits. In high-risk children, the probability of a deficit was 17% in those without infection or encephalopathy, 30% in those with infection, and 40% in those with encephalopathy.

Intrapartum fetal hypoxia: a study of long-term morbidity.

Reported is the second phase of a prospective follow-up study of 37 children who had episodes of intrapartum fetal hypoxia at delivery identified by an acid-base assessment and of a control group of 59 children who had no evidence of intrapartum fetal hypoxia. The newborn infants were normally grown and mature at delivery. Follow-up assessments of motor, cognitive, and language development were made between 1 and 6 years of age. There was no significant difference in the pattern of physical growth and the incidences of motor and cognitive handicap or developmental delay, language developmental delay, and tests of vision and hearing in the children of the hypoxia group and the children of the control group. These findings suggest that acid-base measures of metabolic acidosis can be used as a method of assessment of the mature normally grown fetus during labor without compromising the long-term outcome of the child.

The prediction of intrapartum fetal metabolic acidosis by fetal heart rate monitoring.

Fetal heart rate characteristics during the 8 hours prior to delivery have been studied in 200 patients in whom the fetus had evidence of a metabolic acidosis at delivery, and compared to those in 200 patients in whom the fetus had a normal acid-base at delivery. Baseline fetal heart rate moderate bradycardia and tachycardia, decreased baseline variability, and decreased fetal heart rate accelerations are predictors of intrapartum fetal hypoxia with metabolic acidosis. Marked patterns of total decelerations and late decelerations are predictive of intrapartum fetal hypoxia with metabolic acidosis. The probability of fetal metabolic acidosis in the presence of a marked pattern of total decelerations is 25%, and with late decelerations it is 48%, in a population of high-risk pregnancies.

The effect of maternal, labor, and fetal factors upon fetal heart rate during the intrapartum period.

The effect of maternal labor, and fetal characteristics upon fetal heart rate behavior during the intrapartum period has been studied in 400 patients. Abnormal labor in comparison to normal labor has a higher baseline fetal heart rate with an increased incidence of baseline tachycardia and an increased incidence of absent or decreased baseline variability. A decreasing fetal weight gestational age percentile is associated with an increased incidence of variable decelerations. Segmental epidural and Demerol analgesia carefully administered has little effect upon fetal heart rate behavior.

The clinical prediction of intrauterine growth retardation.

From a total study group of 8,030 deliveries, 2,788 patients with risk factors and 292 representative patients from the 5,242 patients without risk factors were selected for detailed analysis of predictors of intrauterine growth retardation (IUGR). Two thirds of the IUGR infants came from the population with risk factors and a weighting was assigned to individual risk factors. One third of the IUGR infants came from the population without risk factors, and their mothers demonstrated significantly differing maternal characteristics from those with a normally grown infant. The perinatal mortality rate was higher in the IUGR group and particularly in the population with risk factors.