Chorionic villus sampling and end-artery disruption of the fetus

Chorionic villus sampling significantly affects fetal cardiovascular function

OBJECTIVE

To assess the effects of chorionic villus sampling (CVS) on fetal heart rate (FHR).

METHODS

A prospective longitudinal study was conducted among 300 patients undergoing transabdominal CVS between 8 and 13 weeks of gestation. Duration of the procedure, number of needle passes, sample weight, maternal age, fetal gender, and FHR response to CVS were recorded.

RESULTS

The FHR before but not after CVS was inversely correlated with gestational age (r = -0.406, p < 0.001). Conversely, following CVS, no correlation was observed between FHR and gestational age (r = -0.06, p = 0.27). The difference between FHR after CVS and that obtained before CVS (delta FHR) increased with increasing gestational age at sampling (r = 0.372, p < 0.0001), decreased with increasing specimen weight (r = -0.16, p = 0.01) and increased with increasing maternal age (r = 0.22, p < 0.0001). Duration of the procedure, fetal gender and number of needle passes did not affect delta FHR. Multiple logistic regression indicated that gestational age at CVS and maternal age but not the other variables significantly affected delta FHR and together they accounted for over 22% of the variance (R(2) = 0.224, p < 0.0001).

CONCLUSIONS

In summary, our results suggest that acute fetal hemodynamic changes accompany CVS and that these changes vary with gestational age.

[Management of 103 limb reduction defects: a French-speaking fetal medicine club enquiry]

OBJECTIVES

Prenatal diagnosis of a limb reduction defect poses difficult medical and ethical problems. Prenatal diagnosis can be at the origin of two opposing medical attitudes, either a medical termination of pregnancy, or the specific management of the child at birth. The objective is to carry out an enquiry of practices and to determine whether there is a threshold in the gravity of the malformation from which the medical termination of pregnancy is accepted.

MATERIAL AND METHOD

The study was carried out by a questionnaire addressed to the members of the French-speaking Club of Fetal Medicine.

RESULTS

Outcome of 103 fetuses with limb reduction defect was described. Prenatal diagnosis and management of observed malformations were explained.

CONCLUSION

Decisions concerning the outcome of the pregnancy are very variable from one couple to another and from one medical team to another. Parents making a request must be given complete information and accompanying psychological support. Collegial with a multidisciplinary team is necessary. For the parents, it is the physician's duty to avoid judgement errors related to anxiety and ignorance of the medical consequences. The physician should guide the parents towards the continuation of the pregnancy or its interruption. The proper decision proceeds from the reunion of the confidence of the couple and the conscience of the physician.

A case of prenatal diagnosis of fetal hydantoin syndrome by ultrasound

Fetal hydantoin syndrome (FHS) is a set of disruptions occasionally present in fetuses exposed in utero to phenytoin or other anticonvulsants. Administration of phenytoin in early pregnancy may impair proper psychomotor performance expected for children's development. Several combined phenotypic markers delineate the syndrome, but the presence of single clinical signs is more common. There is controversy about the etiology of FHS. Associated disruptions may be related to a deficiency in a detoxifying enzyme (epoxide hydrolase), vascular problems, and/or factors not yet known. Genetic causes are believed to influence susceptibility to the drug. This text reports an unusual pattern of malformations detected in an ultrasound scan (gastroschisis, sacral meningomyelocele, and absence of the right lower limb) and in the anatomopathological study (left-side gastroschisis, sacral meningomyelocele, scoliosis, left clubfoot, absence of the right lower limb, and pectus carinatum) of a fetus whose mother took phenytoin. These defects may have been provoked by exposure to the drug during embryogenesis. In view of similar malformations observed in cases of prenatal exposure to cocaine, a recognized vasoconstrictor, it is suggested that vascular disruptions of hemodynamic origin constituted the event leading to some of the anomalies caused in the developing embryo. A complication of the chorionic villus sampling procedure, used for cytogenetic analysis, is another possibility.

Methotrexate-resistant form of dihydrofolate reductase protects transgenic murine embryos from teratogenic effects of methotrexate

Methotrexate, a potent inhibitor of the ubiquitously expressed enzyme dihydrofolate reductase, induces limb and facial anomalies that resemble vascular disruptions in their evolution and final outcome. Previous studies suggest that inhibition of dihydrofolate reductase is responsible for methotrexate-induced embryopathy, although specific sites of methotrexate activity have not been well defined. In this report, we show that constitutive expression of a methotrexate-resistant form of dihydrofolate reductase in transgenic embryos and their placentas ameliorates methotrexate teratogenicity. However, expression of the transgene in maternal tissues had no significant protective effect. The results confirm the role of dihydrofolate reductase inhibition in the pathogenesis of methotrexate-induced birth defects and provide a foundation for future studies of targeted transgene expression in select embryonic or placental cell populations.