Kenneth L. Garver

Etiology of Recurrent Pregnancy Losses and Outcome of Subsequent Pregnancies

Prospective evaluation of 155 couples with two or more consecutive pregnancy losses disclosed uterine morphologic abnormalities in 27%, chromosomal abnormalities in 21 individuals (7.7%, or 15.4% of the couples), and at least one abnormal diagnostic test suggestive of a cause for recurrent pregnancy losses in 106 (68%). A positive test for antinuclear antibody was found in 7.5% of the women, whereas the expected rate in a population of this age is less than 2%. Cervical cultures for Ureaplasma urealyticum (T-strain my-coplasma) were positive in 48% of the women, and 28% of these women had a genetic or uterine abnormality to explain their pregnancy losses. Thyroid function profiles and cervical cultures for Mycoplasma hominis provided no significant information in the evaluation in these couples. With the exception of women with a positive antinuclear antibody, the overall prognosis for later pregnancies was quite good whether the diagnostic evaluation of the couple was normal (77% subsequent live births) or abnormal (71% subsequent live births). The significance of the positive antinuclear antibody in these women is unclear, but further studies and long-term evaluation are necessary to determine the relationship between recurrent pregnancy losses and later development of collagen-vascular diseases.

Origin of Lactate Dehydrogenase in Amniotic Fluid

The origin of protein including enzymes in amniotic fluid is of clinical and research interest. 8 patients were evaluated, with their informed consent, prior to therapeutic abortion. Amniotic fluid, placentas and blood were obtained and lactate dehydrogenase (LDH) isozyme patterns of cell-free amniotic fluid was compared to the LDH patterns of uncultured amniotic fluid cells, maternal serum and RBC, placentas and placental membranes. The LDH isozyme pattern of amnion closely corresponded to that of cell-free amniotic fluid and represents the major source of this enzyme in amniotic fluid.

Mosaicism or Pseudomosaicism: The Problem of Hypermodal Cells in Amniotic Fluid Cell Culture

A series of 2029 consecutive amniotic fluid specimens studied for prenatal genetic diagnosis were reviewed and reassessed so as to evaluate the frequency and clinical significance of hypermodal cells in amniotic fluid cell cultures. Hypermodal cells were defined as those with more than 46 chromosomes, and were characterized by an additional structurally normal or structurally abnormal chromosome. Of 2029 specimens, 47 (2.31 per cent) contained a total of 167 hypermodal cells. True fetal mosaicism was detected in three cases (0.14 per cent). All had hypermodal cells in more than one culture flask or colony which contained the same aberrant chromosome complement. In all but one case the babies were normal when only one cell was hypermodal, or when several cells were hypermodal but present in only one colony or one culture vessel. One case had an extra No. 20 chromosome in one cell. Although the child had multiple anomalies, they were not characteristic of trisomy 20, and subsequent chromosomal study on the baby postnatally revealed a 46,XX karyotype. The in situ coverslip technique is recommended as the preferred method for prenatal diagnosis, and it is useful as an aid in differentiating true mosaicism from pseudomosaicism.