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Biomedical subjects

J C Pons

Publications and source records attributed to J C Pons.

At least 19 recordsLinked to original sources
PubMed1995

[Multiple pregnancies].

Multiple pregnancies do raise the extraordinary problem of their frequency: conceptions of this type have taken on epidemic proportions as a result of the growth of infertility treatment. The study details the obstetric management, neonatal outcome, and follow-up data of women who were delivered of twins, triplets and more. The management of multiple pregnancies includes early diagnosis, meticulous follow-up, and early decrease of maternal activity. Data on the prognosis of triplet pregnancies are of particular importance when the option of selective termination is considered. The most common complication is preterm labor. The prematurity rate is 50% in twin, 95% in triplet and 100% in multiple pregnancy of higher order. The perinatal mortality was 20 to 80 per 1,000 in twins and 40 to 250 per 1,000 in triplets. During last years, a number of changes took place: introduction of medically assisted procreation, early diagnosis via ultrasound scans, considerable increase in the number of cesarean sections in the case of multiple pregnancies, improved prognosis for premature and growth retarded newborns.

Female↗
PubMed1995

[Congenital toxoplasmosis: transmission to the fetus of a pre-pregnancy maternal infection].

It has been established that maternal immunity developing before conception protects the fetus from congenital toxoplasmosis. We observed a case of congenital toxoplasmosis consecutive to a maternal toxoplasma infection that had preceded pregnancy. A woman with normal immune system developed toxoplasmosis 2 months before conceiving. No treatment was given to this prepregnancy seroconverted patient. At 25 weeks of amenorrhoea, the ultrasound examination showed a fetal cerebral ventricular dilatation. Amniocentesis and cordocentesis showed fetal toxoplasmosis infection. Fetopathologic examination confirmed the diagnosis of cerebral toxoplasmosis. The pathophysiology of maternal-fetal toxoplasma transmission and the role played by maternal immunodeficiency are discussed. This exceptional case-report showed the difficulties of the management in patients with 3-month pre-pregnancy toxoplasmosis and its practical implications.

Abortion, Therapeutic↗
PubMed1995

Is prevention of preterm births in twin pregnancies possible? Analysis of the results of a prevention program in France (1989-1991).

OBJECTIVES: A policy aimed at the prevention of early preterm births in twin pregnancies has been evaluated. The prevention program included: early diagnosis of twinning, information of the mothers about the risk of prematurity, attempts to restrain physical activity and early work leave prescription when indicated. STUDY DESIGN: Cohort study of all twin births in a given geographical area (Hauts-de-Seine district); 546 mothers with pregnancy duration of > or = 26 weeks were included; 1088 newborns were followed up to the 28th day of life. RESULTS: The recommended prevention program is largely used (88% of early diagnosis of twinning, 62% of the women informed and 73% of prescription for reduced physical activity). The very preterm (26-28 weeks) and early preterm (< or = 32 weeks) birth rates are low: 1.5 and 8.5%, respectively. The stillbirth rate is 11 per thousand and the neonatal mortality rate (0-27 days) is 10 per thousand live births, with a persistent difference between the first and the second twin. CONCLUSION: The present study demonstrates the open access and acceptability of the prevention policy; in addition, the perinatal outcomes are better than those of comparable published cohorts.

Cohort Studies↗
PubMed1995

Ultrasound evaluation of the length of the fetal nasal bones throughout gestation.

Subtle facial abnormalities, including smallness of the nose, are common findings in trisomy 21 and numerous other genetic conditions. The aim of this study was to construct a normal range for the length of the fetal nasal bones with gestation in a Caucasian population. Ultrasound measurements were performed on a strictly mid-sagittal profile in 376 normal singleton fetuses at 14-34 (mean 24) weeks' gestation. It was found that the length of the nasal bones increased from 4 mm at 14 weeks to 12 mm at 35 weeks' gestation, and that there was a linear relationship between the length of these bones and biparietal diameter and femur length. We conclude that the length of nasal bones can easily be measured in fetuses at 14-34 weeks' gestation and that such measurements might prove useful in the evaluation of pregnancies at high risk for associated fetal abnormalities.

Embryonic and Fetal Development↗
PubMed1994

Thrombocytopenia in pregnant women infected with human immunodeficiency virus: maternal and neonatal outcome.

OBJECTIVES: Our purpose was to evaluate the prevalence of thrombocytopenia related to human immunodeficiency virus among seropositive pregnant women and its impact on maternal and neonatal outcome. STUDY DESIGN: A retrospective survey of all deliveries of women infected with human immunodeficiency virus in 14 maternity units in France over a 6-year period collected data on mothers who had thrombocytopenia < 100.10(9)/ and their infants. RESULTS: Among 890 women, 29 were thrombocytopenic (3.2%, 95% confidence interval 2.1% to 4.3%). Thrombocytopenia appeared directly related to human immunodeficiency virus infection in 25 of these women. During pregnancy 16 patients were treated for thrombocytopenia with zidovudine, corticosteroids, or high-dose intravenous gamma globulin. Zidovudine was effective in five of seven cases, and intravenous gamma globulin was effective in five of 11 cases. Cesarean sections were performed in 13 of 29 women. Abnormal intrapartum or postpartum bleeding was recorded in five cases. Among 28 infants for whom neonatal platelet counts were available, only one had thrombocytopenia < 100.10(9)/L at birth; he went on to have early-onset acquired immunodeficiency syndrome. CONCLUSIONS: The incidence of fetal or neonatal thrombocytopenia appears low and may not justify invasive sampling or routine cesarean delivery. Therapy with zidovudine or intravenous gamma globulin should be considered for women with severe thrombocytopenia, because of the risk of maternal hemorrhage.

Adult↗
PubMed1994

Methods of motor performance evaluation: application to a primate model for basal ganglia pathology.

In studies on the motor impairments induced in monkeys by performing lesions of various kinds on the central nervous system, it is necessary to be able to exactly quantify the motor deficits. The battery of tests described in the present paper (simple and choice reaction-time procedures, goal-directed pointing movement, digital manipulation task) provide a systematic means of analysing the motor performances involving movement control. Central nervous dysfunction can be induced by either reversibly or permanently excluding specific structures. An example of the motor impairments observed after lesion of the substantia nigra is given which provides an animal model for hemi-parkinsonism.

Animals↗
PubMed1994

Flecainide distribution, transplacental passage, and accumulation in the amniotic fluid during the third trimester of pregnancy.

OBJECTIVE: To study the disposition of flecainide acetate and its transplacental passage (both into the fetus and in the amniotic fluid) during the third trimester of pregnancy. DATA SOURCES: Reference articles and books are identified in the text. A literature review is presented. CASE SUMMARY: Flecainide distribution, transplacental passage, and accumulation into the amniotic fluid were studied in a patient at term presenting with a fetal supraventricular tachycardia diagnosed at 33 4/7 weeks of gestation. The fetal tachycardia was accompanied by cardiac failure with placental anasarca and hydramnios. Flecainide 100 mg po bid was prescribed initially; by the time of delivery, the dosage had been decreased to 50 mg bid. At delivery day (39 5/7 weeks), the pharmacokinetics of total flecainide were studied at plateau. DATA SYNTHESIS: The concentrations of flecainide at birth in fetal and maternal blood and in amniotic fluid were 235.4, 241.2, and 6426.5 micrograms/L, respectively. Calculation of a fetomaternal blood accumulation ratio of 0.97 showed that, at this gestational age, flecainide penetrates the placental membrane easily without accumulation in fetal blood. In contrast, the concentration of flecainide in amniotic fluid was approximately 27-fold that measured in maternal peripheral blood. Our results suggest the following: (1) close to term, the metabolic clearance (fetal hepatic clearance) of flecainide offers a high yield and its excretion by the fetal kidney is efficient; (2) given that amniotic fluid is constantly swallowed, it seems that, in contrast to what is seen in adults (relative oral bioavailability > or = 95 percent), the oral bioavailability of flecainide is possibly low in the fetus at term or close to term; under such circumstances, the drug would accumulate passively within the gestational sac; and (3) an alternative explanation is that the concentration in the fetus is, in part, the result of both transplacental crossing of the drug and reabsorption orally from the amniotic fluid. CONCLUSIONS: The regular therapeutic monitoring of flecainide is necessary and sufficient in the mother as the concentrations found appear to accurately reflect the degree of fetal accumulation. Because previous studies in infants and children have indicated few toxic adverse effects attributed to flecainide, it appears that the risk to a sucking infant of ingesting toxic amounts of flecainide in human breast milk is very low. Finally, the child of the patient described here has normal initial growth and development at the present time. The transplacental penetration of a drug can be considered, according to gestational age and the disorder being treated, as being of no consequence, dangerous, or desirable. Flecainide appears to fall into this last category.

Adult↗
PubMed1993

Magnetic resonance imaging of the fetus: a study of 20 cases performed without curarization.

Twenty patients underwent magnetic resonance imaging (MRI) at a mean gestational age of 32 weeks. There were 12 patients with suspected fetal brain abnormality and four with intrauterine growth retardation (IUGR), while the remaining four cases were studied for other reasons. The MRI examinations were performed on a 0.5 Tesla machine, with surface coils. One minute acquisition time T1 sequences were used. All the studies were performed without fetal curarization, and only under maternal sedation using flunitrazepam given per os 1 h before MRI examination. Three examinations were incomplete because of fetal movement artefacts. In the remaining cases, MRI allowed the examination of fetal brain anatomy. In five cases, it helped to differentiate isolated hydrocephalus and corpus callosum agenesis. Sub-ependymal nodules were depicted in a case of fetal tuberous sclerosis. One suspected arachnoid cyst was proved to be an ultrasound artefact. Decreased fetal fat on MR images was correlated with low birth weight in cases of IUGR. Due to its better spatial resolution, ultrasonography was more accurate for the diagnosis of facial and lumbar anomalies. Fetal MRI may be performed without curarization. Surface coils allow the detailed analysis of brain parenchyma, and thus MRI is especially useful in the difficult prenatal diagnosis of fetal brain abnormalities.

Adipose Tissue↗
PubMed1993

[Treatment failure of preventive zidovudine in maternal fetal transmission of HIV].

The role of zidovudine therapy during pregnancy in women infected with HIV-1 is still controversial. A case of a 40-year-old woman, seropositive for HIV-1 since a blood transfusion in 1984 is reported. She was treated by zidovudine since 1989 because of a CDC stage IIIb. The treatment was continued throughout pregnancy at the dose of 600 mg per day. A cesarean section was performed in the 40th week of amenorrhoea. The newborn weighed 3940 g. Viral culture was negative at birth, but positive at the age of four months. Zidovudine and its glucuronide were measured by high performance liquid chromatography in maternal blood taken by venopuncture, in amniotic fluid and in cord blood. In our case, zidovudine was ineffective in preventing transmission of HIV to the fetus despite of a concentration in cord blood higher than minimal therapeutic concentration in vitro. It must be pointed out that all cases of lack of efficacy of zidovudine were described in patients with CD4-cell count lower than 250 per cubic millimeter.

Adult↗
PubMed1992

Fetal karyotype from cystic hygroma fluid.

In cystic hygroma (CH) fetuses, hydrops fetalis and anamnios make it difficult or impossible to obtain amniotic fluid or cord blood for cytogenetic analysis. We report six cases of CH in which cytogenetic analysis was simply and successfully performed using nuchal fluid cells. The karyotypes were 47,XY, + 18,46,XY,46,XX, and 45,X (n = 3).

Cytodiagnosis↗
PubMed1992

[Medical and ethical problems posed by the prenatal diagnosis of distal absence of a limb].

Eight cases of distal amputation of limb are reported. The diagnosis were made by ultrasound scans at 18-25 weeks of amenorrhea. In all cases, according to the French law, our team of fetal medicine refused the therapeutic terminations of pregnancy requested by the parents. The therapeutic terminations of pregnancy were achieved by another unit of fetal medicine in France, or in another country. These reported cases address many questions about the aim of fetal medicine (therapeutic terminations of pregnancy or treatment of infants), the place of the parents request in the decision, the different decision arguments, and the variations in the decision between different fetal medicine crew facing to similar prenatal diagnosis.

Abortion, Legal↗
PubMed1992

[Quadruplet pregnancies: management and obstetric and pediatric outcome].

Multi-fetal gestations are associated with increased frequency of maternal, fetal and neonatal complications. Data on the prognosis of multi-fetal pregnancies are of particular importance when the option of selective termination is considered. The present study details the obstetric management, neonatal outcome, and follow-up of seven quadruplet pregnancies in a french university center. The perinatal mortality was 250/1000. The neonatal mortality was 214/1000. The incidence of respiratory distress syndrome was 38%, bronchopulmonary dysplasia 19% and intraventricular hemorrhage 9.5%. Follow-up from one to 16 years shows that no child is handicapped. Our specific management for higher order multi-fetal pregnancies include early diagnosis, meticulous follow-up, early decrease of maternal activity, midwives at home, psychological care, delivery by cesarean section and a neonatalogist for each baby at the time of delivery.

Abortion, Therapeutic↗
PubMed1992

[RU 486 (mifepristone) and therapeutic abortions in the second and third trimesters].

RU 486 activity for therapeutic pregnancy termination through prostaglandin was studied in a controlled survey including 50 patients, in the second and third trimester of pregnancy (in conformity with the French law). Patients were randomly divided into two groups. The first one was administered orally 200 mg of RU 486, 48 hours before the first Sulprostone injection. The control group did not receive any RU 486. The mean duration between prostaglandin administration and miscarriage was significantly shorter in the RU 486 group (13.16 hours), than in the control group (23.16 hours). Women with RU 486 treatment needed less prostaglandin doses and, above all, had less prostaglandin secondary effects than the patients in the control group.

Abortifacient Agents, Nonsteroidal↗