Fetal supraventricular tachycardia and cystic fibrosis: Coincidence or association? Two case reports.

Prenatal diagnosis of cystic fibrosis (CF) is difficult and is mainly considered upon identification of digestive sonographic signs. Although such an association has never been described until now to our knowledge, we report two cases of fetal arrhythmia associated with cystic fibrosis. This association may be explained by the physiopathology of heart in the context of CF, but nevertheless needs to be confirmed by other reports. The prenatal diagnosis of CF is important in order to implement early appropriate care, with better prognosis. The finding of possibly new associated prenatal signs may then improve the global management of the disease.

Are all cases of low-grade mosaic trisomy 13 in amniotic fluid with no fetal malformation in fact confined placental mosaicism? A case report.

We report on a case of true prenatal mosaic trisomy 13 on amniotic fluid associated with a normal phenotype at the age of 6 years. The amniocentesis was performed because of advanced maternal age and was controlled by a second sample. Morphological and cardiac ultrasonography did not reveal any fetal malformations. No trisomic cells were found in the fetal blood and a nuclear magnetic resonance imaging (IRM) of the brain was performed during the third trimester found no abnormality of the brain. Finally, at birth cytogenetic analysis was performed on two placental samples for chromosomal analysis: one in an area where the placenta seemed normal, and the other one in an area with infarcted and hemorrhagic aspect. We found a high rate of trisomic cells in the sample with abnormal aspect. Furthermore, no trisomic cell was observed by fluorescent in situ hybridation (FISH) on the buccal smears of the baby. We concluded to a confined placental mosaicism. The good outcome of the child aged 6 years confirms this diagnosis. So in the aim to predict a good development for the child in case of low rate mosaic trisomy 13 in amniotic fluid, we propose at birth: i) to take several samples from the placenta to confirm placental mosaicism; ii) to label by FISH buccal smears with a LSI 13 probe to prove that the baby is not a carrier of the trisomy.

Familial 18 centromere variant resulting in difficulties in interpreting prenatal interphase FISH.

We report here on a familial case of centromeric heteromorphism of chromosome 18 detected by prenatal interphase fluorescence in situ hybridization (FISH) analysis transmitted by the mother to her fetus, and resulting in complete loss of one 18 signal. The prenatal diagnosis was performed by interphase FISH (AneuVysion probe set, and LSI DiGeorge 22q11.2 kit) because of the presence of an isolated fetal cardiac abnormality, and was first difficult to interpret: only one centromeric 18 signal was detectable on prenatal interphase nuclei, along with one signal for the Y and one for the X chromosome. The LSI DiGeorge 22q11.2 kit also showed the absence of one TUPLE 1 signal on all examined nuclei. In fact, the FISH performed on maternal buccal smear displayed the same absence of one chromosome 18 centromeric signal, combined with the presence of two TUPLE1 signals. All these results led to the diagnosis of an isolated 22q11.2 fetal microdeletion that was confirmed on metaphases spreads. This case illustrates once again that the locus specific (LSI) probes are more effective than the alpha centromeric probes for interphase analysis. The development of high-quality LSI probes for chromosomes 18, X and Y could avoid the misinterpretation of prenatal interphase FISH leading to numerous additional and expensive investigations.

[Hyperhomocysteinemia and pregnancy: a dangerous association]. / Hyperhomocystéinémie et grossesse : une association dangereuse.

Homocysteine results from the demethylation of the essential amino acid methionine. Its metabolism depends primarily on three enzymes and several vitamin cofactors (vit. B6, B9 and B12). Genetic abnormality in these enzymes or deficiency of these vitamins lead to Hyperhomocysteinemia. Hyperhomocysteinemia belongs among the congenital thrombophilies and is a long-known vascular disease risk factor. The discovery that hyperhomocysteinemia may also be responsible for several pregnancy complications has only recently been made. Studies in this area are still scarce and report on limited numbers of patients. It nevertheless appears clear that HHCh is associated with the syndromes of repeated miscarriage, pre-eclampsia, placenta abruptio, thromboembolic events, neural tube defects, and perhaps with fetal death-in-utero and intra-uterine growth retardation. Supplementation with vitamin B9 can reduce plasma HC levels, and is thus recommended in patients with HHCh. The prevention of thromboembolic events during pregnancy by anticoagulant treatment is also desirable in these patients.

Primary fetal hydrothorax: A literature review and proposed antenatal clinical strategy.

OBJECTIVE: To investigate the prognostic factors for primitive fetal hydrothorax (PFHT) and propose a clinical strategy based on systematic literature review. METHODS: We reviewed 64 articles describing 204 cases of PFHT. For each case we focused on 11 criteria. We investigated prognostic factors in the 89 cases where no in utero treatment was undertaken. We also studied the impact of different in utero treatments on the evolution of PFHT. RESULTS: We have found 4 factors correlated with the course of PFHT: the presence of hydrops, gestational age at time of birth, the unilateral or bilateral nature of the effusion, and the occurrence of spontaneous resolution. With multivariate analysis, only hydrops remained determinant as a prognostic factor. CONCLUSIONS: Studies such as ours, reviewing case reports or series, are subject to the biases of literature underreporting of therapeutic failures or nonintervention. However (with the best available data) we propose a clinical approach to PFHT discovered in utero.