Biomedical subjects

H L Brown

Publications and source records attributed to H L Brown.

At least 37 records · Page 2Linked to original sources

PubMed1991

Antiphospholipid antibodies and recurrent pregnancy loss.

Women with antiphospholipid antibodies have a significant risk of reproductive failure and adverse pregnancy outcomes. The incidence of recurrent abortion, fetal death, and intrauterine fetal growth retardation is significant. Women with a history of recurrent abortion and unexplained fetal death or a history of recurrent thrombotic episodes should be screened for the presence of antiphospholipid antibodies. The benefit of routine screening of pregnant women for the presence of these antibodies has not been established, and the yield from such screening studies has been found to be low. No treatment regimen has eliminated fetal loss and adverse pregnancy events completely in women with the antiphospholipid antibody syndrome. Even when treatment is instituted, maternal and fetal status must be monitored closely. Management of such patients has not been standardized, and various treatment regimens have been found to be efficacious. Multicenter randomized treatment trials are currently underway, and standardization of therapy in these patients may be achieved.

Abortion, Habitual↗

PubMed1991

Obstetric complications in young teenagers.

We compared pregnancy outcome in 286 teenaged primigravidas (less than or equal to 16 years old) and 267 adult primigravidas (21 to 25 years old) who had similar prenatal care, socioeconomic status, and racial balance. The incidence of preterm labor and delivery of a low birthweight infant was significantly higher in the teenagers. The incidence of preeclampsia was significantly higher in the adults. Cesarean delivery was not done more frequently in teenagers, nor was there a higher incidence of infants small for gestational age, anemia, and abnormal presentation in labor. The birthweight of infants of black teenagers was significantly lower than the birthweight of those of white teenagers, and overall birthweight was significantly lower in infants of teenagers than those of adults. Although prenatal care, socioeconomic factors, and racial balance were comparable for young teenagers and adults, teenagers were still at a significantly greater risk for delivery of smaller infants, preterm labor, and low birthweight infants.

Adolescent↗

PubMed1991

Anticardiolipin antibodies in unselected pregnant women. Relationship to fetal outcome.

Anticardiolipin antibodies (ACLA) have recently been associated with adverse fetal outcome. The prevalence of elevated ACLA has not been studied in unselected pregnant women, however. Twelve hundred unselected pregnant women were screened for IgG ACLA using an assay standardized by the first international workshop on ACLA. Fifteen (1.25%) were positive for IgG ACLA (greater than 3 SD above the mean) but only 0.5% had moderate to high levels of IgG ACLA (greater than 5 SD above the mean). Low levels of IgG ACLA were not associated with increased risk of fetal loss; however, 50% of women with moderate to high levels of antibody had fetal wastage. These findings further support the association of significantly elevated levels of IgG ACLA with fetal loss.

Adolescent↗

PubMed1990

Umbilical cord blood gases for term healthy newborns.

Examination of paired umbilical arterial and umbilical venous blood gases for 147 term, healthy newborns revealed a strong correlation of pH, bicarbonate, and base excess with the 1-minute Apgar score. Although significantly different from each other, a strong correlation existed between the gas measurements of the two vessels. The lower limit of pH for the umbilical artery was 7.12 and for the vein, 7.25. The arterial-venous difference for bicarbonate but not pH, oxygen or carbon dioxide tension, or base excess was correlated with the 1-minute Apgar score.

Apgar Score↗

PubMed1990

Umbilical cord blood gas assessment of twins.

Umbilical cord arterial and venous blood gas values were compared in 63 twin pairs, of which 57 pairs had birth weights of 1500 g or more each. Small differences between the first and second twins existed for PO2, PCO2, and pH. However, bicarbonate values did not differ significantly. These cord gas differences represent minor respiratory aberrations, as reflected by a tendency toward carbon dioxide retention by the second twin. Route of delivery, time interval between deliveries, and nonvertex presentations were not associated with significant deviations from these observed acid-base patterns.

Apgar Score↗

PubMed1990

Clinical chorioamnionitis is not predicted by an ultrasonic biophysical profile in patients with premature rupture of membranes.

A modified biophysical profile was assessed serially in 47 patients with premature rupture of membranes who were not in labor. This profile included fetal movement, fetal tone, fetal breathing, amniotic fluid volume, and placental grade. The most recent study, obtained within 2 days of delivery, was compared with pregnancy outcome as reflected by the development of chorioamnionitis and/or neonatal sepsis. No study patient received antibiotics, steroids, or tocolytics before labor. Neither the composite biophysical profile nor any of its components were found to be different between patients with and without clinical chorioamnionitis. Neonatal sepsis was not observed. These data do not support the use of the biophysical profile as a predictor of maternal infection.

Birth Weight↗

PubMed1989

In utero growth of the large-for-menstrual-age fetus.

In a cross-sectional study of 87 large-for-menstrual-age term infants, intrauterine growth was found to be linear, 34 g per day. Differences between diabetic and nondiabetic pregnancies were not evident.

Embryonic and Fetal Development↗

PubMed1989

Estimating fetal weight in patients with preterm premature rupture of the membranes.

Fetal weight estimation was performed in 58 women with preterm premature rupture of the membranes within 4 days of delivery. Of twelve formulas evaluated, only two met the requirements for clinical use (i.e., they had a small mean percent error and a high correlation). However, both had high random error, which may be attributable to the very low birth weights studied.

Birth Weight↗

PubMed1989

Strategic planning.

Explore the source record for details and available documents.

Decision Making, Organizational↗

PubMed1988

Estimated fetal weight: applicability to small- and large-for-gestational-age fetus.

Ultrasonic formulas using femur length and abdominal circumference with or without biparietal diameter were found to be highly accurate in predicting the weight of normal-sized term infants. The small-for-gestational age fetus, however, was overestimated and the large-for-gestational-age fetus was underestimated. The fetal weight formulas tested that were appropriate for the entire study group were not applicable to those fetuses having altered growth.

Abdomen↗

PubMed1988

Fetal weight estimates in diabetic gravid women.

Fetal weight in utero was estimated sonographically within one week of delivery in 70 live-born fetuses of diabetic gravidas. The best estimates of weight were obtained with formulas dependent on biparietal diameter, abdominal circumference, and femur diaphysis length, and with formulas using the two variables of femur diaphysis length and abdominal circumference. Use of a special formula for the fetus of a diabetic mother was not of additional benefit. Acceptable weight estimates for the macrosomic diabetic fetus were not obtained.

Birth Weight↗

PubMed1988

Ultrasonographic identification of the macrosomic fetus.

Ultrasonographically determined biparietal diameter, femur length, abdominal circumference, and estimated fetal weight were analyzed with regard to their ability to predict the macrosomic newborn. Receiver operating characteristic curves were plotted for each of these variables. Estimated fetal weight was superior to biparietal diameter or femur length measurements in the identification of the overgrown fetus. Because of limitations of positive predictive values and sensitivities, application of these observations varies with the clinical setting in which they are used.

Abdomen↗

PubMed1988

The relationship of placental grade to fetal size and growth at term.

Among 246 term patients undergoing ultrasonic evaluation within 1 week of delivery, a grade-three placenta was found in 39.4%. Advanced placental maturity was not associated with altered fetal growth rates or an increase in small- or large-for-gestational infants. At term, advanced placental maturity is not associated with aberrant fetal growth.

Birth Weight↗

PubMed1988

Fetal overgrowth. Diabetic versus nondiabetic.

Term, large for gestational aged newborns were retrospectively evaluated. The fetal parameter of relative growth, was measured using the ratio of fetal length to abdominal circumference (FL/AC). This measurement was not different between diabetic and nondiabetic gravidas who delivered LGA infants when ultrasound was obtained within 1 week of delivery.

Anthropometry↗

PubMed1988

Premature placental calcification in maternal cigarette smokers.

Ultrasonographic examinations, including placental grading, were done in 145 smoking and 100 nonsmoking low-risk obstetric patients at 37 weeks' gestation. Extensive calcification--grade III changes--occurred significantly more often in smokers than in nonsmokers (36 versus 14%; P less than .0001). Two groups of smokers, consuming five to 15 cigarettes per day or one or more packs per day, also had significant differences in grade III placenta when compared with nonsmokers. Smokers under age 20 years were more likely to have premature grade III changes; however, parity did not influence premature placental calcification in smokers and nonsmokers. The incidence of small for gestational age infants delivered was not significantly higher in smokers, and grade III placental changes appeared to occur no more often in SGA infants of smokers than of nonsmokers. Our findings suggest that the smoking gravida is at increased risk for premature placental calcification.

Adult↗

PubMed1987

Recognition of the overgrown fetus: in utero ponderal indices.

In a cross-sectional study of 210 pregnancies resulting in above-average-sized term infants, ponderal and ponderal-like indices were found to be highly correlative with fetal overgrowth. Clinical usefulness, however, is limited because for each index, most large-for-gestational age infants remain unidentified.

Birth Weight↗

PubMed1987

Plasma and amniotic fluid prostacyclin and thromboxane in mild pregnancy-induced hypertension.

To study the involvement of 6 keto prostaglandin F1 alpha (6 keto PGF1 alpha) and thromboxane B2 (TxB2) in mild pregnancy-induced hypertension (PIH), we measured amniotic fluid and plasma concentration of these prostanoids by radioimmunoassay in PIH subjects and normotensive pregnant controls. The results suggest no difference in plasma or amniotic fluid 6 keto PGF1 alpha or plasma TxB2 in PIH and control subjects. The concentration of TxB2 (mean +/- SE) in amniotic fluid, however, were 189.5 +/- 27.7 for PIH and 107.4 +/- 9.7 for controls (P less than 0.05). This increase in vasoconstrictor TxB2 over vasodilator 6 keto PGF1 alpha may have implications in the hypertensive vascular response of mild PIH.

6-Ketoprostaglandin F1 alpha↗

PubMed1987

Ultrasonic recognition of the small-for-gestational-age fetus.

Sonar biparietal diameter, femur length, abdominal circumference, femur length/abdominal circumference ratio, ponderal index, and estimated fetal weight were obtained within ten days of delivery of small-for-gestational-age (SGA) (N = 102) and non-SGA (N = 204) newborns. The effectiveness of each ultrasound variable in the antenatal recognition of the SGA fetus was assessed. An abnormal abdominal circumference was the best predictor, confirming SGA in 98% of cases. Other variables (biparietal diameter, femur length, femur length/abdominal circumference ratio, ponderal index, or estimated fetal weight) were less accurate for predicting SGA. When we determined expected results based on a 10% prevalence of SGA, negative predictive value was greater than 92% for all variables studied; however, with the exception of estimated fetal weight and femur length, positive predictive values were disappointing, including abdominal circumference (21%). This report establishes the limits of ultrasound-derived growth variables in the antenatal identification of the SGA fetus.

Birth Weight↗