Fetal ultrasound abnormalities: Correlation with fetal karyotype, autopsy findings, and postnatal outcome—five‐year prospective study

Abstract

A 5-year prospective prenatal study in 151 pregnancies with 152 malformed fetuses detected by ultrasound was evaluated cytogenetically. Thirty-five fetuses (23%) had abnormal karyotypes. Specific anatomical fetal malformations identified by ultrasound increase the risk for fetal chromosome abnormalities. Risks of abnormal chromosomes in the fetus are present with both single and multiple anomalies including amniotic fluid volume although the risk is increased with specific anatomical systems and multiple malformations. An abnormal fetal karyotype was present in 17% with a single anatomical abnormality and 30% when two or more anatomical systems were involved. Fetal hydrops, duodenal atresia, and omphalocele were the most specific single ultrasound anomalies; fetal hydrops, IUGR, holoprosencephaly, congenital heart disease, diaphragmatic hernia, duodenal atresia, and omphalocele were the most specific multiple anomalies with abnormal amniotic fluid volume. Termination of pregnancy occurred in 32/58 patients diagnosed prior to the 20th week of pregnancy with most (31/32) having a chromosomal anomaly or severe fetal anomaly. Fetuses terminated after the 20th week had chromosomal (7/18) or lethal fetal anomalies (11/18). The most common aneuploidies were trisomy 21, trisomy 18, and 45,X. The decision to terminate the pregnancy was based in most cases on the fetal ultrasound findings. Correlation of ultrasound and clinical findings is important for accurate genetic counselling.

Fetal Abnormalities Detected by Sonography in Low-Risk Pregnancies: Discrepancies between Pre- and Post-Termination Findings

“…Amniocentesis because of maternal age or an increased risk of chromosomal anomaly resulted in 26% of the terminations, and the other 7% were equally distributed between recurrent birth defects screened by performing level-2 ultrasound examination and biological or enzymological tests. During the period sur veyed, prenatal karyotyping after the discove ry of a prenatal ultrasound anomaly was pro gressively being introduced into France and was finally recognized as recommended stan dard medical practice [18,19].…”

Use of array comparative genomic hybridization for prenatal diagnosis of fetuses with sonographic anomalies and normal metaphase karyotype

“…Prior studies demonstrate that metaphase karyotype provides a diagnostic explanation for the fetal anomaly in approximately 16–30% of cases, depending on the gestational age of the fetus and the presence of single or multiple anomalies (Wilson et al ., 1992; Rizzo et al ., 1996). If the structural anomaly is accompanied by a high clinical suspicion for a particular genetic condition, i.e.…”

Fetal Mild Hydronephrosis and Chromosomal Defects: Relation to Maternal Age and Gestation

“…An example of such an abnormality is mild hydronephrosis or pyelectasia, which is found in about 2% of mid-trimester fetuses [2], In the combined data from five studies on a total of 631 mid-trimester fetuses with mild hydro nephrosis, the frequency of chromosomal de fects was 8% (table 1) [2][3][4][5][6], Although the majority of chromosomally abnormal fetuses had additional defects, even in those with apparently isolated hydronephrosis, the prev alence of chromosomal defects was 2%. How ever, it is uncertain whether this prevalence truly reflects an increased risk over that ex pected on the basis of the maternal age and gestational age distribution of the populations examined.…”