Biomedical subjects
Publications and source records attributed to B K Young.
Spondylothoracic dysplasia, also known as short-trunk dwarfism or Jarcho-Levin syndrome, is a fatal autosomal recessive disorder characterized by vertebral and spinal defects with a short thorax. Until recently, in utero diagnosis could only be made radiographically. Sonographic criteria for antenatal diagnosis are discussed in conjunction with a review of the literature.
A right adrenal gland mass was found during sonographic examination of the right upper quadrant during a workup for hyperemesis gravidarum. Magnetic resonance imaging was used to clarify the origin of the mass. The tumor was nonfunctional. Because of the possibility of a malignancy, the patient underwent a successful second-trimester exploratory laparatomy with right adrenalectomy. Pathology demonstrated a benign ganglioneuroma.
Thoracic aortic aneurysm is associated with increased morbidity and mortality in pregnancy. Successful pregnancy with vaginal delivery after repair of a traumatic aortic aneurysm is described.
A pregnancy complicated by vaginal stenosis six years after diagnosis of Stevens-Johnson syndrome is described. The pathologic changes in the vagina have not previously been reported. The basic pathology of severe mucosal erythema multiforme was present, as well as ectasia of the superficial capillaries and small venules. The effect of the vaginal scars on the mode of delivery is discussed.
Riboflavin concentration was measured in sera of a control population and in a series of paired maternal and cord sera. The assay technique was carefully validated and appears to be specific and reproducible. The mean riboflavin concentration in 12 apparently healthy adults was 116 +/- 46 nmol/L (SD). In 20 uneventful pregnancies the cord serum concentration was generally higher than the maternal concentration (158 +/- 47 nmol/L versus 113 +/- 35 nmol/L; p = 0.001). The cord-to-maternal ratio in paired sera averaged 1.45 +/- 0.44. There was no detectable difference in binding of riboflavin to cord and maternal serum proteins as measured by equilibrium dialysis (59.0% +/- 17% versus 60.8% +/- 16%). Comparison of protein binding by paired cord and maternal sera yielded a ratio of 0.99 +/- 0.13. The transplacental gradient of riboflavin concentration is unrelated to protein binding and is consistent with active transport by the placenta, as previously demonstrated in vitro.
To differentiate pregnancies complicated by oligohydramnios due to intrauterine growth retardation from those due to renal agenesis, the authors administered furosemide intravenously to eight pregnant women (19-25 weeks gestation) with oligohydramnios. The fetal abdomen was scanned with ultrasound to demonstrate the fetal urinary bladder. In six fetuses, sonography failed to demonstrate the bladder: two fetuses had growth retardation with normal kidneys and bladder, and four had renal anomalies. It is concluded that administration of furosemide to the mother fails to induce diuresis in growth-retarded fetuses of 19-23 weeks gestation and that failure to see the fetal bladder after furosemide administration does not necessarily indicate absent fetal kidneys.
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This is the first report to date on biochemical parameters in triplets. Umbilical artery and venous pH, PO2, PCO2, lactate and base deficit were measured in seven sets of triplets. Other parameters compared were route of delivery, one- and five-minute Apgar score, birth weight, relative birth order and sex. Twenty-one viable infants were born from three induced and four spontaneous pregnancies. Female: male sex ratio was 1.6:1.0. All triplets within a set were delivered by the same route--six sets by cesarean section and one set vaginally. There were no significant differences, according to Student's t-test, in birth weight, Apgar scores and biochemical parameters related to birth order. Comparison of umbilical artery and umbilical venous pH, PO2, PCO2, lactate and base deficit differences did not demonstrate evidence of acidosis or significant base deficit in the third triplet when compared with the first two, suggesting that the duration in utero after deliver of the firstborn is not associated with metabolic acidosis or hypoxia in the absence of any obstetric complication or anesthetic problem.
Despite the clinical impression that firstborn twins do better than second-born twins, recent reports have shown no difference in perinatal mortality between them. In order to evaluate differences in twins, more sensitive means than perinatal deaths are necessary. This study examines differences between 80 firstborn and second-born twin pairs with respect to Apgar score, umbilical venous and arterial blood gas, and acid-base data. The umbilical venous and arterial blood PO2, PCO2, base deficit, pH, and lactic acid concentration were measured in paired samples and compared with the paired t test and chi 2 when applicable. Statistically significant differences favoring twin A, the firstborn, were found in 1-minute Apgar score, umbilical venous pH, PO2, and PCO2, and umbilical arterial PO2. The other factors in umbilical venous and arterial blood did not show statistically significant differences. When these parameters were examined with respect to route of delivery, monochorionic and dichorionic twins, interval between twins, and vertex twins only, with the possible effects of malpresentation eliminated, the results persistently favored the firstborn twin. Thus it is unequivocally demonstrated that there are substantial differences at birth favoring the first twin, despite similar perinatal mortality for both. The data suggest that the second-born twin has potentially greater susceptibility to hypoxia and trauma.
This is the second report of endometrioid carcinoma of the ovary associated with an intrauterine pregnancy. The previous report presented six cases, making this the seventh. Characteristics of the tumor are reviewed, as are the guidelines for the management of ovarian carcinoma complicating pregnancy.
The prenatal diagnosis and postpartum confirmation of hydranencephaly is discussed. The need for an adequate knowledge of fetal cranial anatomy when performing obstetric sonography is stressed.
Simultaneous measurements of maternal arterial and umbilical cord blood pH, PCO2, and base deficit at delivery were studied in 168 live-born infants and their mothers. The correlations between maternal and umbilical parameters were highly significant (P less than .001) and were greater in vigorous than in depressed newborns. Mothers of vigorous acidotic infants had a lower pH and a higher base deficit than those of vigorous nonacidotic infants (P less than .001). However, the maternal-fetal differences were wider in the vigorous acidotic than in the vigorous nonacidotic newborns for all three parameters, and in both umbilical vein and umbilical artery (P less than .001). The data indicate that maternal acidosis accounts only partially for the acidosis observed at the time of delivery in the apparently normal fetus. With neonatal depression, the degree of acidosis is not dependent on maternal pH but on other factors. These factors may be influenced by maternal acidosis, but they are the major reasons for the neonatal depression, not the maternal acidosis.
One thousand thirty-two neonates were evaluated with umbilical venous and arterial blood samples drawn at delivery for assessment of pH, PO2, PCO2, and base deficit. These values were statistically correlated with Apgar scores in all of the neonates studied. Infants were divided into Apgar groupings (group A, greater than or equal to 7 at one and five minutes; group B, less than 7 at one minute, greater than or equal to 7 at five minutes; group C, less than or equal to 7 at both one and five minutes). Generally, umbilical artery and umbilical venous data were parallel. The differences in means for pH, PO2, PCO2, and base deficit was significant when group A was compared with group B in both umbilical artery and umbilical venous data. However, a severe degree of biochemical disturbance must take place before significant association with neonatal depression can be made. It appears that umbilical blood biochemical data are related to fetal metabolic status before birth but only modestly influence the one-minute Apgar score.
Fifty-three fetal heart rate (FHR) tracings obtained by direct ECG monitoring during labor and 24 simultaneous external Doppler FHR tracings were analyzed for the quantitative assessment of baseline FHR variability. The beat-to-beat difference in FHR subsumed by 90% of all beat-to-beat changes within a tracing was taken as the index of variability of that tracing. This index correlated well with the visual assessment of variability for both internal ECG records (Spearman rank correlation coefficient, rs, = 0.71) and external Doppler records (rs = 0.78). However, there was no correlation between the variability index of the Doppler FHR records and that of simultaneous ECG FHR records (r = 0.11, p greater than 0.6). This finding casts doubt on the use of the presence of "normal" FHR variability as a sign of fetal well-being during antepartum FHR monitoring with current Doppler equipment.
Umbilical arterial lactate, pH, PO2, PCO2, and base deficit were measured at delivery of 468 live-born infants. The correlation between the 1-minute Apgar score and lactate (r = -0.34) was comparable to that between the 1-minute Apgar score and pH (r = 0.30). The multiple correlation coefficient between the 1-minute Apgar score and all five parameters combined (lactate, pH, PO2, PCO2, and base deficit) was 0.36. This was not significantly higher than the simple correlation coefficient for pH alone (0.30). Similar correlation coefficients were noted for the 5-minute Apgar score. The dividing point between normal and pathologic lactate levels was 3.70 mmol/L. A pH less than 7.20 and a lactate level greater than or equal to 3.70 mmol/L had the same sensitivity, specificity, and positive and negative predictive values for low Apgar scores (less than 7). While pH and lactate are equally correlated with fetal outcome, their combination with each other and with other blood gas parameters does not predict outcome better than either pH or lactate alone.
Estriol (E3), the most abundant estrogen in pregnancy is produced predominantly in the placenta from androgen precursors of fetal origin. The estriol so formed is secreted efficiently into the maternal circulation where it is converted to 4 conjugates--estriol-3-sulfate (E3-3S), estriol-16-glucosiduronate (E3- 16G ), estriol-3-glucosiduronate (E3- 3G ) and estriol-3-sulfate-16-glucosiduronate (E3-SG). The order of renal clearances is E3- 16G greater than E3- 3G greater than E3-3S approximately E3-SG. Unconjugated E3 and E3- 3G differ from the other forms of estriol in that their removal from the blood compartment is essentially irreversible. E3-3S, E3- 16G and E3-SG undergo interconversions during enterohepatic circulation and eventual partial conversion to E3- 3G . Following delivery of the fetus and placenta, unconjugated E3 is no longer detectable in the maternal serum within 1-2 h, whereas the concentrations of the conjugates decline more slowly, the rates being determined by the rates of renal clearance and enterohepatic interconversions. E3- 3G levels were dramatically elevated in a case of Group C polycystic kidney disease, providing evidence that this conjugate is indeed an end-product of estriol metabolism.
Simultaneous measurement of fetal heart rate (FHR), uterine contractions (UC), continuous fetal tissue pH (TpH) and transcutaneous pO2 (tcpO2) was attempted in 40 high-risk parturients monitored for an average duration of 117 +/- 74 min. There were only two failures (9%) in the last 23 cases, with satisfactory recording of all parameters in 78% of the total. At present, the feasibility of simultaneous biochemical monitoring is limited to the active phase of labor. Fetal scalp and umbilical arterial blood pH and pO2 were obtained as well. The biochemical data showed a good correlation between tcpO2, scalp capillary pO2 and umbilical artery pO2 (P less than 0.02). The correlation was not significant between similar pH comparisons, although an average difference of 0.04 pH units was observed between the final tpH and umbilical artery pH. Both fetal TpH and tcpO2 fell progressively during labor. Preliminary findings comparing TpH, tcpO2 and FHR suggest that changes in tcpO2 rapidly reflect changing maternal and fetal conditions, while TpH responds more slowly and less sensitively.