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Biomedical subjects

T B Lebherz

Publications and source records attributed to T B Lebherz.

At least 37 records · Page 2Linked to original sources

Chromosome findings in 2,500 second trimester amniocenteses.

We have analyzed the chromosome abnormalities found in 2,500 amniocenteses for prenatal diagnosis; 1,887 (75%) were performed because the maternal age was 34 years or more. Chromosome abnormalities were detected in 1.80% of those referred for advanced maternal age, 1.2% between ages 34 and 39 years and 4.6% 40 years and over. Of these, four occurred in women who would have been 34 years at delivery (2.9%). Trisomy 21 accounted for 50% of the chromosome abnormalities; sex chromosome abnormalities, for 25%; the remaining 25% was divided equally between trisomy 18 and partial trisomies and mosaics. Unexpected translocations were found in 0.4%, of which two-thirds were balanced and identified in one parent. The accuracy was 99.6%.

Amniocentesis↗

Follow-up of 2000 second-trimester amniocenteses.

The authors analyzed the outcome of 2000 consecutive second-trimester amniocenteses. Seventy-three percent were performed for maternal age of 34 years or more. The risk of spontaneous abortion before 28 weeks' gestation was 1.3% and for stillbirth or neonatal death, 1.4%. Total fetal loss was 2.7%, compared with 2.2% in a control population. Congenital malformations were found in 1.6% of the study group and in 1.9% of controls; no increase in skeletal problems was observed. Prematurity, defined as a birth weight of less than 2500 g, was noted in 3.6%, compared with 3.7% and 3.9% in 2 control populations. Respiratory difficulties persisting for more than 24 hours were observed in 0.8% of patients, compared with 0.7% of controls. Analyses of the outcome of amniocenteses performed at a single large center do not show an increase in perinatal complications or malformations.

Abortion, Spontaneous↗

Neural tube defects: maternal serum screening and prenatal diagnosis.

Neural tube defects represent some of the most common and serious of the congenital malformations. Although elevation of alpha-fetoprotein in amniotic fluid is not diagnostic, it does indicate an abnormality of the fetus in a very high proportion of cases. A normal level, however, does not exclude the possibility of a closed neural tube defect. It is therefore recommended that all amniocenteses performed between 15 and 20 weeks of gestation include measurement of alpha-fetoprotein. Maternal serum alpha-fetoprotein assay is a screening test and pilot studies will be necessary to determine its value as a routine prenatal blood test.

Amniocentesis↗

Identification of a bactericidal factor (B-lysin) in amnionic fluid at 14 and 40 weeks' gestation.

Amnionic fluid (AF) specimens from 40 normal obstetric patients at 14 to 16 weeks' gestation and at 37 to 40 weeks' gestation were found to contain both lysozyme and a bactericidal substance identified as B-lysin. The concentrations of both lysozyme and B-lysin were significantly higher in the AF at 40 weeks' than at 14 weeks' gestation. B-lysin concentration in AF were also found to be significantly higher than in either cord or maternal blood.

Amniotic Fluid↗

Prenatal genetic diagnosis in 350 amniocenteses.

Three hundred and fifty second trimester amniocenteses performed for prenatal diagnosis of genetic disorders are reported. One hundred and ninety-three of these were performed because maternal age was greater than 35 years, and 6 fetuses with unbalanced chromosomal abnormalities (3%) were identified. Thirteen procedures were performed because a previous child had had a neural tube defect; 1 anencephalic fetus was identified. Ninety-six percent of the initial taps were cultured successfully; we failed to obtain amniotic fluid in 3% of patients. The risk of a spontaneous abortion occurring at some time after the amniocentesis was 0.85%, and no cases of fetal injury were identified.

Adult↗