Search PubMed⌕ Search

Biomedical subjects

A C Allen

Publications and source records attributed to A C Allen.

At least 73 records · Page 4Linked to original sources
PubMed1987

Preterm birth at 23 to 26 weeks' gestation: is active obstetric management justified?

To determine if active perinatal management was justified in preterm deliveries at less than or equal to 26 weeks' gestation, the outcome (survival and short- and long-term morbidity) of 43 infants (group I) born between 23 and 26 weeks' gestation was compared with that of 17 infants (group II) born at 27 weeks' gestation. Of the 12 surviving infants in group I (survival 28%), 11 were ventilated (median = 50 days), eight had moderate to severe bronchopulmonary dysplasia, and four had mild retrolental fibroplasia. At follow-up, two infants had physical disabilities with moderate to severe functional impairment, one had a minor disability, and nine had normal neurodevelopment. In contrast, of the 13 surviving infants in group II (survival 76%), nine were ventilated (median = 8 days), six had moderate to severe bronchopulmonary dysplasia, and six had mild RLF. At follow-up, one infant had a physical disability with moderate to severe functional impairment, four had minor disabilities, and eight had normal development. Perinatal factors that positively influenced survival in the two groups combined included active perinatal management, antenatal steroids, female sex, and absence of clinical chorioamnionitis and asphyxia. Although group I infants had a significantly higher mortality rate (p less than 0.05) and required a longer duration of ventilation (p less than 0.05), no differences in the incidence of postnatal complications or long-term morbidity at 2 to 4 years of age were evident between the two groups.

Child Development↗
PubMed1987

Fetal biophysical profile and perinatal death.

Antepartum assessment of 5034 high-risk pregnancies to predict perinatal death included five biophysical variables (nonstress test, fetal breathing movements, fetal movements, fetal tone, and amniotic fluid volume) which combined to form a biophysical profile score. We assessed 4148 fetuses within seven days of delivery. The ability of each variable to predict perinatal death was expressed as the likelihood ratio, which incorporates sensitivity and specificity into one number. The predictive ability was most accurate with fetal movement (likelihood ratio 48.1) and the combined biophysical profile score (likelihood ratio 51.0). The biophysical profile score was more likely to predict perinatal death due to asphyxia (seven of eight) than lethal anomaly (six of 19). The overall perinatal mortality was 7.6 per 1000 total births. The perinatal mortality rate was 1.0 for a normal biophysical profile score, 31.3 for an equivocal score, and 200.0 for an abnormal score. The false-negative rate for the biophysical profile score was 0.7 per 1000.

Amniotic Fluid↗
PubMed1985

1H nuclear magnetic resonance of heroin's D ring.

The 1H nuclear magnetic resonance (NMR) chemical shifts and coupling constants of heroin's D ring H-15 alpha, H-15 beta, and H-16 alpha, and H-16 beta are presented. These assignments were accessible through the introduction of a double bond (delta 15,16) in heroin. The resulting compound, delta 15,16 didehydroheroin, was subjected to deuterium exchange or stereoselective reduction or both. Reduced products d1-16 alpha heroin d2-15 alpha, 15 beta-heroin, and d3-15 alpha, 15 beta, 16 alpha-heroin are presented. Heroin with deuterated acetyls is also presented for 1H NMR spectral clarity in the D ring area.

Chemical Phenomena↗
PubMed1984

Antepartum fetal assessment using a fetal biophysical profile score.

The application of the fetal biophysical profile score in the management of 2,400 high-risk pregnancies was assessed. The negative predictive value for normal perinatal outcome was not improved compared to single variable tests. The positive predictive value for abnormal perinatal outcome was improved. The overall perinatal mortality in 2,485 fetuses was 9.2 per 1,000. In the 1,980 fetuses with a normal biophysical profile score within 7 days of delivery, excluding lethal anomalies, the perinatal mortality was 1 per 1,000. Fetal movement counting is supported as the most valid and appropriate test for universal fetal screening.

Amniotic Fluid↗
PubMed1984

Follow-up study of survivors of fetal and early onset neonatal listeriosis.

Although fetal or neonatal infection with Listeria monocytogenes is known to have a high mortality, the longterm morbidity is unknown. Clinical sequelae of fetal or neonatal listeriosis were studied in eight survivors of such infections at a mean age of 16 months corrected for prematurity. A developmental and health history was taken and a Denver Developmental Screening Test and neurological exam performed on each subject. Two infants were seen again and the remainder had developmental and health histories obtained from their mothers and primary physicians at a mean age of 31 months. Six of the eight infants studied had no evidence of neurodevelopmental sequelae. Four of these six had mild or no clinical disease after birth. However, two of the six intact survivors, both born prematurely, were critically ill in the early postnatal period. The two remaining infants had neurodevelopmental handicap. In addition to being prematurely born with severe perinatal disease, these two had CNS complications in the newborn period, both with meningitis and one with intraventricular hemorrhage. Although intelligence in both appeared to be normal, one had mild and the other moderate spastic diplegia. Severe perinatal disease, including fetal or neonatal death, appeared to be related to delayed or no antepartum antibiotic therapy of mothers. Premature delivery appeared to be an important factor both in the severity of disease and in the development of longterm handicap. There were no deaths and no longterm sequelae in infants born at a gestational age greater than 37 weeks. However, in the absence of meningitis and other CNS complications, it would appear that the prognosis even for prematurely born survivors of perinatal listeriosis is very good.

Adult↗
PubMed1981

Progressive hydrocephalus in infants with birth weights less than 1,500 g.

Premature infants have been frequently observed to manifest hydrocephalus after intraventricular hemorrhage (IVH). For the complete newborn population of Nova Scotia in 1976 to 1978, we found a very low incidence of hydrocephalus in children whose birth weight was less than 1,500 g. Eighty-two percent of these babies were born in a perinatal center; 18% were transported. Chart review of survivors (58%) and autopsy review of deaths (autopsy rate, 86%) showed that in the province's three neonatal intensive care units, only four of 314 such babies manifested progressive hydrocephalus. Only one of four infants was examined after IVH. An IVH was noted at autopsy in 42% of cases. No survivor manifested hydrocephalus one to three years later as judged by head circumference and neurosurgical records. Our results may reflect the impact of regionalized perinatal care, or that post-IVH hydrocephalus is rare in an unselected population.

Cerebral Hemorrhage↗
PubMed1980

Neonatal asphyxia. I. Relationship of obstetric and neonatal complications to neonatal mortality in 38,405 consecutive deliveries.

The requirement of greater than one minute of positive pressure ventilation was prospectively used to identify infants suffering from asphyxia at birth in 38,405 consecutive deliveries. Multivariate analysis of high-risk factors associated with increased risk of asphyxia showed the prematurity was the most significant predictor of asphyxia. Asphyxia occurred in 62.3% of infants less than 27 weeks' gestation and decreased to 0.4% in infants greater than 38 weeks' gestation. Presence of asphyxia was associated with significant increase in neonatal mortality of infants greater than 36 weeks' gestation. Of the asphyxiated neonates, growth retardation, hypothermia, hyaline membrane disease, and seizures were significantly associated with an increased risk of death.

Asphyxia Neonatorum↗
PubMed1979

Overt diabetes in pregnancy.

Of 45 diabetic pregnancies, 80% were Class C, D, or R. The perinatal mortality rate was 4.4% (corrected 2.2%); however, neonatal morbidity was high. Of the infants, 28% developed respiratory distress syndrome (RDS); 18%, asphyxia; and 42%, hypoglycemia. Thus, the woman with overt diabetes needs delivery in an institution where neonatal expertise and modern neonatal facilities exist. Of the mother 28% had a family history that was negative for diabetes mellitus. Four neonates developed RDS despite mature lecithin/sphingomyelin ratios.

Abortion, Induced↗
PubMed1975

Actinomycosis infections associated with intrauterine contraceptive devices.

A series of 10 instances of genital actinomycosis infection complicating the use of intrauterine contraceptive devices is recorded and its pathogenesis described. The likelihood is suggested that this complication is more frequent than is generally appreciated. A pathway of infection extending upward from the patient's anus, across the perineum, and up the vagina and cervix is suggested as the route of infection. The traumatizing effect of the device and a previously existing or intercurrent infection as additional contributing factors to the development of actinomycotic infection in the female genitalia is also postulated.

Abscess↗