[The value of prenatal chromosomal diagnosis in cases of fetal abnormalities: results obtained in 468 pathological pregnancies]. / Intérêt du diagnostic chromosomique prénatal en cas d'anomalies foetales: résultats obtenus dans 468 grossesses pathologiques.

The authors report the results of 468 foetal karyotypes performed on amniotic fluid or foetal blood samples after ultrasound discovery of foetal anomalies. A total of 46 chromosomal aberrations (10%) were detected. The rates of anomalies vary considerably according to the alarm sign; very high (greater than 30%) in cases of multiple malformations, foetal hydrops or foetal death, low (less than or equal to 2%) in cases of poly- or oligohydramnios and foetal growth retardation without detectable malformation. In addition to these chromosomal diagnoses, further investigations enabled in 9 cases the diagnosis of genetic autosomal recessive disorders. Our results which are comparable with those reported in the literature, demonstrate the importance of prenatal diagnosis in cases of pathological pregnancies, with regard to obstetrical and perinatal management as well as to genetic counseling.

A comparison between multiple and single pregnancies obtained by in-vitro fertilization.

Thirty-eight single and 10 multiple pregnancies obtained after in-vitro fertilization were compared. In the group of multiple gestations, maternal age was lower and the amounts of ovulatory drugs given were significantly smaller than in relation to single pregnancies. All multiple pregnancies arose from triple embryo transfers and the embryos from this group exhibited significantly higher vitality scores. In both groups, plasma levels of oestradiol and progesterone followed the same pattern until day 8 after oocyte retrieval. Following implantation, the secretion of these hormones increased more rapidly in multiple pregnancies pointing at greater luteal activity in this group. HCG levels became significantly higher in multiple gestation on day 25 after oocyte collection. Echographic examination showed that, compared to normal pregnancy, growth in both groups of IVF conceptuses was initially retarded but caught up with normal evolution at approximately 30 days after egg retrieval. The need for adjusting the number of embryos transferred not only to expected success rates but also to the risk of high rank multiples is emphasized.

Lethal osteopetrosis with multiple fractures in utero.

Severe osteopetrosis was diagnosed in utero in two successive pregnancies resulting from an intermarriage. Hydrocephaly and skeletal hyperdensity were detected at 18 weeks of gestation, and fractures at 24 weeks. We report on extensive ultrasound, radiological, and pathological findings, including those on brain and bone. The markedly reduced number of osteoclasts observed in these sibs and the very early fetal involvement suggest that this form of osteopetrosis might represent a new entity: autosomal recessive lethal osteopetrosis.

Pathological pregnancies. Results of amniotic fluid studies and fetal outcome.

Late amniocenteses (greater than 20 weeks' gestation) were performed in 114 pregnancies with no a priori genetic risk, but referred because of abnormal clinical and/or ultrasound findings suggesting fetal malformations. Reasons for referral included polyhydramnios (51 cases), oligohydramnios (15 cases), fetal growth retardation (FGR) (16 cases) and abnormal fetal ultrasound findings excluding anencephaly (32 cases). In 42 of these cases, referral was motivated by a combination of the above abnormal findings. When polyhydramnios was the sole anomaly (25 cases), 5 fetuses were malformed (20%), abnormal fetal karyotype and/or elevated amniotic fluid alphafetoprotein (AFP) were demonstrated in 2 cases. Oligohydramnios was the sole anomaly in one case; the infant died of prematurity. Fetal growth retardation was the sole anomaly in 14 cases, 11 otherwise normal newborns were small for date, 2 died at birth and 1 was malformed (1/14, 7%). In this group all fetal karyotypes were normal and in 2 cases amniotic fluid AFP were increased. In the 32 pregnancies without abnormal amniotic fluid volume and/or FGR and with fetal malformation(s) suggested by ultrasound, all malformations except one (ovarian cyst possibly ruptured during birth) were confirmed at birth, amniotic fluid AFP was elevated, and/or karyotype was abnormal in 6 cases. In 42 pregnancies where more than one alarm sign was present, abnormal karyotype and/or elevated amniotic fluid AFP level were recorded in 21 of the 39 cases where amniocentesis was performed, 33 fetuses were malformed (79%) and 13 died in the perinatal period (31%). The high incidence of abnormal results of amniocentesis found in this survey of pathological pregnancies, particularly in those with multiple alarm signs, emphasizes the need for amniocentesis in these situations.

A case of partial sirenomelia and possible vitamin A teratogenesis.

Prenatal echographical findings of a partial sirenomelic fetus are described. An attempt was made to terminate pregnancy by administration of prostaglandin F2 alpha, but uterine rupture occurred. The teratogenic role of vitamin A ingested by the mother in the periconceptional period is discussed.

Lethal multiple pterygium syndrome.

We report on two fetuses with a lethal form of multiple-pterygium syndrome born to first cousins. The two pregnancies aborted spontaneously in the 2nd trimester, the fetuses, 10-11 weeks of embryonic age, showing multiple pterygia and multiple cartilaginous fusions. One had cleft lip and palate. In both cases the microscopic anatomy of the placenta showed villi with scalloped border and intravillous trophoblastic invaginations.