Changes in alpha 1-acid glycoprotein serum concentrations and glycoforms in the developing human fetus

alpha 1-Acid glycoprotein concentrations and reactivity to concanavalin A were measured in maternal and fetal serum and amniotic fluid obtained from 24 women undergoing diagnostic cordocentesis at 20 to 33 wk gestation and in 30 additional fetal sera (19 to 34 weeks gestation). Maternal alpha 1-acid glycoprotein serum levels were five to ten times higher than fetal and amniotic levels. Fetal alpha 1-acid glycoprotein levels were found to increase with advancing gestational age. Using crossed immunoaffino electrophoresis with concanavalin A, alpha 1-acid glycoprotein patterns were identical in maternal serum and amniotic fluid but totally different in fetal serum. The fetal concanavalin A pattern changed progressively during fetal life towards that of the newborn. These data confirm earlier assumptions of fetal synthesis of alpha 1-acid glycoprotein and provide normal reference values for alpha 1-acid glycoprotein in fetal serum. In addition, the specific fetal concanavalin A pattern indicates that the alpha 1-acid glycoprotein glycosylation process during fetal life differs from that in post-natal life.

[Infectious fetal diseases. Prevention, prenatal diagnosis, practical measures]

Many congenital infections can produce foetal diseases and are sometimes responsible for major disablements. The most frequent infectious foetal diseases are toxoplasmosis, rubella and chickenpox. Diseases caused by parvovirus or cytomegalovirus are exceptional. Foetal blood sampling has considerably simplified the prenatal diagnosis and made it accessible to more medical centres; it has also widened the therapeutic possibilities and above all, it has considerably reduced the number of therapeutic abortions. It may well be that the development of molecular biology, which has the great advantage of permitting an earlier diagnosis, will in the near future make it possible not only to detect numerous monogenic diseases before birth, but also to diagnose some foetal infections. We might then hope that a much earlier treatment in utero will also be more effective.

Prenatal diagnosis of fetal cytomegalovirus infection

Twelve fetuses were evaluated with a combination of ultrasonography, amniocentesis, and blood sampling for possible cytomegalovirus infection. In seven the mother had a documented primary cytomegalovirus infection. All seven women had normal ultrasonographic findings and one fetus was found to be infected. In the other five cases fetal cytomegalovirus infection was diagnosed in association with abnormal ultrasonographic findings. There was no history of maternal infection in the latter group. All positive and negative diagnoses were confirmed and none of the six infected fetuses survived. In this series, the most reliable parameters of infection were the isolation of the virus from amniotic fluid and elevations of total immunoglobulin M and gamma-glutamyl transpeptidase in fetal blood. In the majority of infected fetuses cytomegalovirus-specific immunoglobulin M was not detected in blood. Prenatal diagnosis of fetal cytomegalovirus infection is possible with a combination of amniocentesis and fetal blood sampling.

Fetal toxoplasmosis: ultrasonographic signs

Eighty-nine cases of proven Toxoplasma gondii fetal infection were studied in order to describe the morphological lesions which could be demonstrated on ultrasound examination; these were present in 32 of the infected cases. Cerebral ventricular dilatation was the most common sign and was generally bilateral and symmetrical. Its evolution was always very rapid over a period of a few days. Other signs observed included intracranial and intrahepatic densities, increased thickness and hyperdensity of the placenta, ascites and rarely pericardial and pleural effusions. Thirteen fetuses demonstrated two or more ultrasound features. Intrauterine growth retardation and microcephaly were not observed. Ultrasonographic assessment of the fetus injected with Toxoplasma gondii is important. It improves the reliability of prenatal diagnosis and is of important prognostic value in cases with severe brain lesions, but is of little value in detecting brain necrosis without ventricular dilatation.

Developmental hematopoiesis in normal human fetal blood

Using an easy and safe procedure for fetal blood sampling in utero, we studied 3,415 fetuses for prenatal diagnosis. Retrospectively, 2,860 normal blood samples, performed from the 18th week of gestation to the end of pregnancy, were selected. Differentials were evaluated in 732 cases. Burst-forming unit erythroid (BFU-E) and erythropoietin (Epo) were measured in 27 and 163 cases, respectively. Total nucleated cell and platelet counts did not change from the 18th to the 30th week of gestation. The lymphocytes represented the main population and the decrease of normoblastic cells made up for the increase in neutrophils. The increase of red blood cells and hemoglobin was substantial during the studied period. At mid trimester threefold more BFU-E were obtained than at birth. Epo levels remained stable throughout the pregnancy and no correlation was found between Epo and gestational age. These normal values of fetal erythropoiesis will improve our knowledge of physiology and provide a better insight into developmental hematopoiesis.

[Fetal toxoplasmosis. In utero treatment with pyrimethamine sulfamides]

The mothers of 52 cases of toxoplasmic fetopathy diagnosed in utero by fetal blood and/or amniotic fluid sampling were treated with the combination pyrimethamine-sulfadiazine (or sulfisoxazole) and by spiramycine. The infants were compared with 51 other infants with congenital toxoplasmosis whose mothers had received spiramycine alone. Patients of both groups received the same pyrimethamine-sulfadiazine and spiramycine treatment after birth. Parasitologic examination of the placenta was positive in 42 and 76.6% of patients, in group I and group II respectively. The newborns had specific IgM in 17.4 and 69.2% of cases respectively in both groups. These differences were significant. The mean specific IgG titer was significantly reduced at birth and 4 to 6 months of age in the first group. Patients in group I had more often subclinical infection than patients of the comparison group: 57% vs 33.3%. They had less often a high cerebro-spinal protein content during the first week. Prenatal treatment with pyrimethamine-sulfadrugs resulted in a less progressing infection at birth. However in cases with clinically patent toxoplasmosis, the frequency of overt localizations and their sequellae was not significantly altered. This might be related to a relatively late onset of the treatment. The pyrimethamine-sulfadrug combination given to mothers of proved infected fetuses can be rewarding. The indication might be extended to well-documented seroconverted mothers if, in the future, the acquired experience and necessary pharmacological studies bring the proof of its innocuousness.

Serum insulin-like growth factors and insulin-like growth factor binding proteins in the human fetus. Relationships with growth in normal subjects and in subjects with intrauterine growth retardation

IGF-I, IGF-II, and their binding proteins (BP) were studied in sera obtained by direct puncture of umbilical cords in utero between 20 and 37 wk of gestation in 103 normal fetuses and in 16 fetuses with intrauterine growth retardation, as well as in the cord blood of 37 normal newborns of 38- to 42-wk pregnancies. In normal fetuses, IGF-I levels were approximately 50 ng/mL and IGF-II levels approximately 350 ng/mL up to the 33rd wk of pregnancy. Thereafter, both increased to reach values two to three times higher at term. Correlations were found between fetal placental lactogen levels and those of IGF-I and IGF-II, which is consistent with the hypothesis that placental lactogen is involved in the regulation of IGF synthesis in the fetus. With weight (either measured at birth or deduced from echographical data) as index of fetal size, IGF-I levels were significantly (p less than 0.001) higher in fetuses with weights above the mean for gestational age than in fetuses with weights below the mean, whereas IGF-II levels were similar in the two groups. Similarly, IGF-I (but not IGF-II) levels in fetuses with intrauterine growth retardation were significantly lower than those in normal fetuses of the same age (p less than 0.01). These findings suggest that, during the latter months of intrauterine life, IGF-I (but not IGF-II) is involved in the control of fetal size. Total fetal BP concentrations were approximately 1/3 those of adults. The fetal electrophoretic profile obtained by Western-ligand blotting bore a strong resemblance to that of subjects with growth hormone deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

[6 cases of toxoplasmosis in twins]

Studies of congenital toxoplasmosis in twins confirm the definite role of the placenta in the modalities and mechanism of fetal contamination. In single-chorion twin pregnancies, clinical manifestations are generally identical in both infants. Conversely, twins from double-chorion pregnancies usually have different clinical patterns; occasionally, only one of the twins is affected (1 case). The diagnosis can be ascertained antenatally by sampling blood from each of the fetuses (2 cases). The cases reported herein illustrate some of the diagnostic pitfalls that may lead to inappropriate discontinuation of monitoring and treatment: negative placental studies, absence of specific IgM antibodies, transient fall in IgG antibody titers, delayed fetal contamination after a negative fetal blood study, and need for routine tests for increased CSF albumin levels.

Fetal platelet counts in thrombocytopenic pregnancy

Fetal platelet counts were assessed by percutaneous umbilical blood sampling in 64 pregnancies (62 women) with maternal thrombocytopenia. In 33 pregnancies associated with chronic immune thrombocytopenia, 11 of the fetuses had platelet counts below 150 x 10(9)/l and 4 were severely thrombocytopenic (less than 50 x 10(9)/l). In 31 pregnancies with symptomless maternal thrombocytopenia as an incidental finding, 4 fetuses were thrombocytopenic, 1 of them severely. Maternal indices, including antiplatelet antibodies, did not correlate with risk of fetal thrombocytopenia; and in those with repeat measurements there was no evidence of benefit from treatment with either corticosteroids (4 cases) or intravenous immunoglobulin (3 cases). Percutaneous umbilical blood sampling, a safe procedure in experienced hands, provides accurate platelet counts in thrombocytopenic pregnancy, as an aid to decisions on mode of delivery and to assessment of treatments.

Presence of gamma interferon in human acute and congenital toxoplasmosis

The production of gamma interferon in acute acquired and congenital toxoplasmosis was studied. Gamma interferon was produced at significant titers (P less than 0.001) in the course of both congenital toxoplasmosis and acquired toxoplasmosis at an early stage of infection, when Toxoplasma gondii was multiplying. Its presence in fetal blood was correlated with the positive inoculation of fetal blood or amniotic fluid into mice (95%). The data suggest that the fetus is able to synthesize gamma interferon as early as week 21 of pregnancy. This test, easily and rapidly performed, could be included among those useful for diagnosing fetal toxoplasmic disease.

Fetal toxoplasmosis: outcome of pregnancy and infant follow-up after in utero treatment

Eight-nine cases of fetal Toxoplasma infection are reported in women treated with spiramycin during pregnancy. Thirty-four pregnancy terminations were performed (2.7% of the total number of acquired Toxoplasma infections during pregnancy). Fifty-two pregnancies were allowed to proceed (43 being additionally treated with pyrimethamine and sulfonamides), leading to the birth of 54 live infants. After a mean follow-up period of 19 months, 41 infants had evidence of subclinical Toxoplasma infection, 12 had a benign form, and one had severe congenital toxoplasmosis (this infant did not receive the additional treatment during pregnancy). Efficacy of the additional treatment with pyrimethamine and sulfonamides was demonstrated by a significant reduction of severe congenital toxoplasmosis and the relative decrease of the ratio of benign to subclinical forms. We recommended that spiramycin treatment be started as soon as possible once the diagnosis of maternal Toxoplasma infection during pregnancy is proved or strongly suspected, because a prolonged time interval between onset of infection and start of treatment seems to be associated with the presence of severe fetal lesions at the time of prenatal diagnosis.

Corticosteroid sulfates in fetus plasma

The sulfates of deoxycorticosterone (DOCS), corticosterone (BS), cortisone (ES) and cortisol (FS) were radioimmunoassayed in umbilical vein blood plasma samples collected in 97 fetuses between 19 and 32 weeks of gestation after extraction and chromatography on Sephadex LH 20 columns. While DOCS and BS displayed a decreasing pattern until 27-28 weeks, FS and ES did not show important variations throughout the period considered. All sulfates, excepted BS, increased at 29-30 weeks but this rise was only significant for FS and ES. Thereafter BS significantly increased while no significant difference could be displayed for the three others. In view of the difference between the patterns of 17-deoxy- and 17-hydroxycorticosteroids, one can speculate that, during this period of pregnancy, a shift in steroid biogenesis might occur towards a more important production of cortisol. DOCS was correlated with BS and with FS but not with ES. FS was correlated with the three other sulfates and with unconjugated F. ES was correlated with BS and FS but not with DOCS or unconjugated E. The significance of these correlations are discussed according to the origin and the metabolic interrelationships of the four steroid sulfates and unconjugated F and E.

Fetal blood sampling

Fetal blood sampling under ultrasound guidance has permitted the opening of the fetal vascular compartment for diagnosis and therapy. Under very strict conditions, this procedure allows the clinician to use fetal blood analysis as a complementary routine examination.

Prenatal diagnosis with biotinylated chromosome specific probes

We have used a Y-chromosome specific DNA probe in a controlled study to determine the presence of Y-chromosome material and to detect numerical abnormalities in uncultured amniotic fluid cells by fluorescent hybridization. Using this non-radioactive method, we correctly predicted fetal sex within 48 h in all but 3 of 54 cases and identified an XYY syndrome. The technique was previously tested with no false-positive or false-negative results on cultured interphase or metaphase nuclei of fetal fibroblasts and adult T-lymphocytes. Fluorescent in situ hybridization was applied to long-term fixed cytogenetic preparations up to 44 months old and was shown to be reliable.

Placental transfer of vitamin K1 and its implications in fetal hemostasis

Vitamin K status was evaluated using coagulation studies and/or vitamin K1 assays in a total of 53 normal fetuses and 47 neonates. Second trimester fetal blood samples were obtained for prenatal diagnosis under ultrasound guidance. Endogenous vitamin K1 concentrations (determined by high performance liquid chromatography) were substantially lower than maternal levels. The mean maternal-fetal gradient was 14-fold at mid trimester and 18-fold at birth. Despite low vitamin K levels, descarboxy prothrombin, detected by a staphylocoagulase assay, was elevated in only a single fetus and a single neonate. After maternal oral supplementation with vitamin K1, cord vitamin K1 levels were boosted 30-fold at mid trimester and 60-fold at term, demonstrating placental transfer. However, these levels were substantially lower than corresponding supplemented maternal levels. Despite elevated vitamin K1 concentrations, supplemented fetuses and neonates showed no increase in total or coagulant prothrombin activity. These results suggest that the low prothrombin levels found during intrauterine life are not due to vitamin K deficiency.

Management of alloimmune thrombocytopenia: antenatal diagnosis and in utero transfusion of maternal platelets

Neonatal alloimmune thrombocytopenia (NAIT) can cause severe bleeding in the central nervous system (CNS) and death or severe neurologic sequelae. The expression of the PLA1 antigen is detectable as early as 19 weeks of gestation. Alloimmunization can therefore lead to fetal thrombocytopenia very early in pregnancy. Until recently, we have had no means of detecting and assessing the severity of fetal thrombocytopenia during pregnancy. The level of the maternal antibody is not of a predictable value since 20% of the mothers had no circulating antibodies in our series. An alternative approach is to carry out investigations on fetal blood samplings. This management leads to an exact knowledge of the fetal status and antenatal diagnosis is feasible as early as the 21st week of gestation. Early diagnosis facilitates appropriate management and makes possible such therapeutic options as in utero maternal platelet transfusions. We report our experience in the antenatal diagnosis and management of nine cases with in utero transfusion in the six cases with severe thrombocytopenia. All neonates did well, with no signs of bleeding at birth. No side effects of therapy were noted after a period ranging from 6 months to 3 years.

Prenatal and postnatal production of IgM and IgA antibodies to rubella virus studied by antibody capture immunoassay

Rubella virus-specific IgM and IgA antibodies were quantitated by antibody capture immunoassay in adults after primary infection and after experimentally induced reinfection. Antibodies to rubella virus were also detected in fetuses whose mothers had rubella before week 18 of pregnancy. IgM and IgA concentrations in fetal blood were determined by radial immunodiffusion and enzyme immunoassay, respectively. In primary postnatal infection, IgM antibodies were consistently found until week 8 after onset of the disease, and after week 14 these antibodies were usually no longer detected. The time of disappearance of rubella virus-specific IgA varied with each individual. After vaccination of previously immune volunteers, no change was noted in level of IgA antibody, and no IgM antibody was detected. In infected fetuses, total IgM and IgA concentrations rose significantly, and rubella virus-specific IgM and IgA antibodies were detected as early as week 22 of pregnancy.

Physiology and management of intrauterine growth retardation: a biologic approach with fetal blood sampling

Intrauterine growth retardation is a major contributor to perinatal mortality and morbidity. The most important obstetric problem is to determine which fetuses are well in utero and which are at risk of irreversible damage or severe and prolonged neonatal morbidity. The optimal timing of delivery is at present made by subjective assessment of clinical variables. We present hematologic and biochemical values obtained by fetal blood sampling of 24 idiopathic fetuses with intrauterine growth retardation to give objective information on which to base clinical management. The results show that there is stimulation of erythropoiesis as well as evidence of red blood cell destruction and liver damage. In many cases there is acute decompensation with acid base abnormalities in a setting of chronic hematologic and biochemical changes.