Prenatal findings in chondrodysplasia punctata, tibia-metacarpal type.

Chondrodysplasia punctata, a skeletal dysplasia with craniofacial dysmorphism and joint contractures can occur with rhizomelia, mesomelia or both. The rhizomelic form is generally lethal, whereas one form of mesomelic chondrodysplasia punctata has been described that is associated with a presumably normal lifespan and intelligence. We describe a case of a fetus suspected prenatally of having rhizomelic chondrodysplasia punctata, who was subsequently diagnosed at 1.5 years of age to have the tibia-metacarpal form of chondrodysplasia punctata. The prenatal sonographic findings of second-trimester micromelic bone shortening and third-trimester proximal femoral stippling may be present in the rhizomelic form but are not specific to this condition.

The prenatal identification of fetal compatibility in neonatal alloimmune thrombocytopenia using amniotic fluid and variable number of tandem repeat (VNTR) analysis.

Most severe episodes of neonatal alloimmune thrombocytopenic purpura (NATP) are caused by antiplatelet alloantibodies against the HPA-1a (PlA1) antigen. However, half of subsequent fetuses produced from a HPA-1a/b father (genotypic frequency 28%) will result in a child who is not affected. Some investigators manage NATP by confirming the fetal platelet phenotype using percutaneous umbilical cord sampling, a procedure that carries a low but real risk of fetal morbidity and mortality. More recently, physicians determine the fetal platelet antigen genotype using DNA derived from amniotic fluid or chorionic villus samples. All therapy is withdrawn for a fetus who genotypes as HPA-1b/b. However, since the fetus is the same genotype as the mother, there can be uncertainty about the origin of the genetic material and thus the validity of the fetal genotype. The inappropriate withdrawal of therapy for a erroneously genotyped fetus could be fatal, and consequently many physicians advocate fetal HPA-1 phenotyping with confirmation using percutaneous umbilical blood sampling. In this report we describe the management of two pregnancies with previously affected infants due to anti-HPA-1a alloantibodies. Both husbands were HPA-1a/b. For the current pregnancies, amniotic fluid was collected at 20 or 29 weeks of gestation, and the platelet genotype indicated that the fetuses were HPA-1b/b. The fetal origin of the amniotic fluid derived DNA was confirmed by the forensic technique of DNA profiling using variable number of tandem repeat (VNTR) analysis. All therapy was withdrawn, percutaneous umbilical blood sampling was not performed, and both women vaginally delivered healthy non-thrombocytopenic infants. The application of platelet alloantigen genotyping using DNA from amniotic fluid cells identified the HPA-1b/b fetus, and VNTR analysis confirmed that the tissue was fetal derived, thus avoiding the necessity for percutaneous umbilical blood sampling. The use of this approach in patients at risk will avoid additional investigation and treatment in approximately one-seventh of all NATP pregnancies involving the HPA-1a antigen.

Determination of the seroprevalence of human immunodeficiency virus infection in gravidas by non-anonymous versus anonymous testing.

From February 16, 1988 to July 15, 1988, a prospective study was undertaken at the University of Illinois Hospital in Chicago to do the following: 1) determine the seroprevalence of human immunodeficiency virus (HIV) infection among our gravid patients, 2) test the hypothesis that methodical counseling would elicit a more thorough recounting of risk factors, and 3) test the hypothesis that those patients who self-identify risk factors represent only a fraction of HIV-positive gravidas. After educational counseling regarding HIV infection, 349 clinic patients (34%) requested non-anonymous HIV testing (group I). Risk factor histories were recorded from these women. Simultaneously, 849 women admitted to labor and delivery were queried with regard to the same risk factors but without preliminary counseling, and then tested anonymously (group II). Nineteen percent (63 of 349) of group I reported risk factors, whereas only 9.6% (82 of 849) of group II reported similar risks (P less than .0001). Two HIV-positive patients were identified in group I, both of whom reported risk factors (seroprevalence 0.6%). Nine HIV-positive patients were detected in group II, but only four reported risk factors (seroprevalence 1.1%). We conclude that methodical counseling may elicit increased reporting of HIV risk factors as compared with questioning without preliminary counseling. Because many HIV-positive patients may be unable or unwilling to report risk factors, selective voluntary testing will not identify all HIV-positive gravidas.

Hormones and cervical ripening: dehydroepiandrosterone sulfate, estradiol, estriol, and progesterone.

Fetal adrenal steroids have been shown to be important in the timing of parturition. Since dehydroepiandrosterone sulfate is converted to estrogen, which is important in cervical softening, levels of dehydroepiandrosterone sulfate together with those of estradiol, estriol, and progesterone were measured and compared in pregnant women undergoing induction of labor with ripe and unripe uterine cervices. While there were no differences between the levels of estradiol, estriol and progesterone in the two groups of women, dehydroepiandrosterone sulfate was significantly elevated in the group of women with ripe cervices. These findings suggest that cervical changes preceding the onset of labor are associated with a significant elevation of maternal dehydroepiandrosterone sulfate levels. Changes in maternal plasma estradiol, estriol, and progesterone levels do not appear to be clinically related to cervical ripeness.

Configuration of the fetal electrocardiogram in ambulatory women in labor monitored with wideband telemetry.

The fetal electrocardiogram (ECG) in 23 ambulatory women in labor was monitored successfully with a single-channel FM telemetry unit with a 0.5-100-Hz wideband receiver to improve the quality of the ECG complex. An inverted QRS complex was seen in a patient with a deceleration and an inverted T wave during a deceleration in a patient confined to bed. A maternal artifact was transmitted in a third. The ECG complex was identical when wired patients were switched to telemetry. Thus, fetal heart rate and ECG configuration can be monitored accurately in ambulatory pregnant women.