Cordocentesis for rapid karyotyping in fetuses with congenital anomalies or severe IUGR

The most relevant chromosomal abnormalities in the north of Rio Grande do Sul, Brazil: 26 years of cytogenetic analysis

From 1992 to 2018, cytogenetic analyses were successfully performed to explore the chromosomal abnormalities of 729 patients, who utilised a pioneering counselling service in the city of Passo Fundo in the northern part of the Brazilian state of Rio Grande do Sul. This city is characterised by a large conglomerate of private and public hospitals. A classical cytogenetic analysis and G-banding were performed using the patient samples. Although normal karyotypes were observed for 562 of the cases, 167 individuals evidenced chromosomal alterations. Among those, 110 exhibited numerical alterations (65.86%), 41 demonstrated structural modifications (24.55%) and 16 showed both numerical and structural chromosomal changes (9.58%). This study describes the diversity of the chromosomal alterations in this region, which have not been previously examined. After 26 years of study, the findings are discussed herein in a self-critical form.

Low maternal concentrations of soluble vascular endothelial growth factor receptor-2 in preeclampsia and small for gestational age

OBJECTIVES

Preeclampsia is considered an anti-angiogenic state. A role for the anti-angiogenic factors soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble endoglin in preeclampsia has been proposed. Soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) has been detected in human plasma, and the recombinant form of this protein has anti-angiogenic activity. There is a paucity of information about maternal plasma sVEGFR-2 concentrations in patients with preeclampsia and those without preeclampsia with small for gestational age (SGA) fetuses. This study was conducted to determine whether: (1) plasma sVEGFR-2 concentration changes throughout pregnancy; and (2) preeclampsia and SGA are associated with abnormalities in the maternal plasma concentration of sVEGFR-2.

STUDY DESIGN

This cross-sectional study included non-pregnant women (n = 40), women with normal pregnancies (n = 135), women with an SGA fetus (n = 53), and women with preeclampsia (n = 112). SGA was defined as an ultrasound-estimated fetal weight below the 10(th) percentile for gestational age that was confirmed by neonatal birth weight. Plasma concentrations of sVEGFR-2 were determined by ELISA.

RESULTS

(1) There was no significant difference in the mean plasma concentration of sVEGFR-2 between non-pregnant women and those with normal pregnancies (p = 0.8); (2) patients with preeclampsia and those without preeclampsia with SGA fetuses had a lower mean plasma concentration of sVEGFR-2 than that of women with normal pregnancies (p < 0.001 for both); and (3) there was no significant difference in the mean plasma concentration of sVEGFR-2 between patients with preeclampsia and those without preeclampsia with SGA (p = 0.9).

CONCLUSIONS

Preeclampsia and SGA are associated with low plasma concentrations of sVEGFR-2. One interpretation of the findings is that plasma sVEGFR-2 concentration could reflect endothelial cell function.

Prenatal diagnosis and genetic analysis of double trisomy 48,XXX,+18

Prenatal diagnosis of simultaneous occurrence of double trisomy involving chromosomes 18 and X is extremely rare. We report on the prenatal diagnosis, genetic analysis and clinical manifestations of a fetus with both trisomy 18 and trisomy X. A 26-year-old, para 1 woman was referred for genetic counselling at 36 weeks' gestation with the sonographic findings of intrauterine growth retardation (IUGR), polyhydramnios, ventricular septal defect, and an enlarged cisterna magna. Both cordocentesis and amniocentesis revealed a consistent karyotype of 48,XXX,+18. Quantitative fluorescent polymerase chain reaction using polymorphic small tandem repeat markers specific for chromosomes 18 and X rapidly determined that both aneuploidies arose as a result of non-disjunction in maternal meiosis II. Our case shows that two non-disjunction events can occur not only in the same parent, but also in the same cell division. Our case also shows that double trisomy, 48,XXX,+18, can demonstrate an enlarged cisterna magna, IUGR and polyhydramnios in prenatal ultrasound.

Detection of chromosomal abnormalities, an outcome of ultrasound screening. The Eurofetus Team

Chromosomal abnormalities were recorded from all the fetuses of women who benefited from sonographic examinations in the Eurofetus centers, excluding those for whom karyotyping was motivated by age or personal history. Among the 378 chromosomal abnormalities recorded, 210 were detected before birth (sensitivity = 55.6%). Down syndrome (trisomy 21) represented 197 cases, or which 68 were detected before birth (sensitivity = 34.5%). Eighty-two of the cases of Down syndrome had associated structural abnormalities; the sensitivity in these cases increased to 57%. Among the 115 cases of Down syndrome without structural abnormalities, 21 (18.3%) had associated abnormal ultrasound findings that led to prenatal detection. Sensitivity of prenatal detection was 58.1% for trisomy 13 and 79% for trisomy 18. For the abnormalities detected before birth, spontaneous fetal death occurred in 27% of cases, and an early termination of pregnancy was decided in 53% of cases.