C. Stoll

Evaluation of prenatal diagnosis of congenital heart disease

Prenatal diagnosis performed by fetal ultrasound scan is now a routine part of antenatal care in many countries. That an increasing number of fetal anomalies may be detected on prenatal ultrasound is beyond doubt. What is possible is not, however, always practical, especially when congenital heart diseases (CHDs) are concerned and when whole antenatal populations are screened rather than high‐risk groups. Thanks to our registry of congenital anomalies, a retrospective study was undertaken to evaluate the prenatal detection of CHDs by ultrasound scan in 131 760 consecutive pregnancies of known outcome from 1979 to 1988. Only 84 out of 912 malformed fetuses with CHDs without chromosomal anomalies were detected (9.2 per cent). The sensitivity of detection varied from around 38 per cent for malformations such as hypoplastic left heart and single ventricle to around 5 per cent for ventricular and atrial septal defects. The effectiveness of the detection of some forms of major congenital heart disease has increased dramatically since 1987 by including routine examination of the four‐chamber view and of the inflow and outflow tracts of the fetal heart. Our results stress the need to obtain a definite clear four‐chamber view, to perform scans at ⩾ 18 weeks of gestation, and to train sonographers in order to improve the prenatal detection of CHDs.

Risk factors in congenital heart disease

Risk factors were studied in 801 children with congenital heart disease (CHD) coming from 105,374 consecutive births of known outcome. The incidence of CHD was 7.60 %o. Diagnosis was performed in 66.5% of the cases during the perinatal period. Two-hundred-fifty seven of the cases also had at least one non-cardiac malformation (multiply malformed). Ninety-two cardiac infants (11.47%) had recognized chromosomal and non-chromosomal syndromes. The most frequent non-cardiac malformations were renal, digestive and limb anomalies. For each case a control was studied. The following features were screened: sex ratio, parity and previous pregnancies, parental age, residency, education, ethnic origin, lenght, head circumference and weight at birth, genetic and environmental factors. Odds ratio values were calculated for the risk factors.Weight, length and head circumference at birth of cardiac infants were less than those of controls. The weight of placenta was also lower than in controls. The pregnancy with CHD was more often complicated by hydramnios and threatened abortions, except in infants with isolated CHD. Oliogoamnios was more frequent in pregnancies producing multiply malformed infants and those with recognized syndromes with CHD. One out of four children with CHD had an extracardiac malformation, which is ten times the rate of incidence of malformation in our population.The incidence of CHD in first degree relatives of these infants was 3.0%. These first degree relatives also had more non-cardiac malformations than did those of the controls.

Evaluation of prenatal diagnosis of congenital gastro-intestinal atresias

Prenatal diagnosis performed by fetal ultrasound scan is now a routine part of antenatal care in many countries. That an increasing number of fetal anomalies may be detected on prenatal ultrasound is beyond doubt. However what is theoretically possible is not, always done in practice specially when gastrointestinal atresias (GIA) are concerned and when whole antenatal populations are screened rather than high risk groups. Thanks to our registry of congenital anomalies a retrospective study was undertaken to evaluate the prenatal detection of GIA by ultrasound scan in 118,265 consecutive pregnancies of known outcome. Only 31 out of 129 malformed fetuses with GIA were detected (24.0%). The sensitivity of detection varied from 51.4% for atresia of the small intestine to 24.2% for esophageal atresia and 8.2% for ano-rectal atresia. No isolated case with esophageal atresia and ano-rectal atresia were diagnosed. Our results stress the need to perform scans at ≥ 18 weeks gestation and to train sonographers in order to improve prenatal detection of GIA.

An epidemiologic study of environmental and genetic factors in congenital hydrocephalus

Risk factors were studied in 96 children with congenital hydrocephalus (CH) coming from 118,265 consecutive births of known outcome. Hydrocephalus with neural tube defects, intracranial tumors or secondary to brain atrophy were excluded. The prevalence of CH was 0.81 per thousand. Diagnosis was performed prenatally in 41 cases. Forty-three (44.8%) of the cases had hydrocephalus without other malformations (isolated hydrocephalus), 18 (18.7%) infants had recognized chromosomal or non-chromosomal syndromes and 35 children (36.4%) had multiple malformations. Each case was matched to a control. Weight and length at birth of children with hydrocephalus were less than in the controls (p < 0.001). The weight of the placenta was lower than in the controls (p < 0.05). The pregnancy with a hydrocephalic child was more often complicated by threatened abortion, polyhydramnios and oligohydramnios. The mothers of children with hydrocephalus and multiple malformations had used oral contraceptives during the first trimester of pregnancy more often than the mothers of the controls. No differences appeared between the mothers of children with CH and the controls for the other risk factors studied: parental age, parity, previous pregnancies, previous stillbirths, smoking, diabetes, epilepsy, X-rays, hypertension, fever “flu”, medication and occupational exposure. There was an increase of parental consanguinity in the parents of our patients (6.2% v. 1.1%, p < 0.001) and first degree relatives had more non-cerebral malformations than the controls (7.3% v. 3.2%, p < 0.05).

Evaluation and evolution during time of prenatal diagnosis of congenital heart diseases by routine fetal ultrasonographic examination

The objectives of this study were to evaluate routine prenatal diagnosis of congenital heart diseases (CHD) by fetal ultrasound examination in a well-defined population during the period 1994-1999 and to compare these results with the results from 1979 to 1993. This study included 80,076 consecutive pregnancies of known outcome from 1994 to 1999. CHD were classified as isolated or associated when at least one other major extra-cardiac malformation was present. Only 137 out of 688 malformed fetuses with CHD without chromosomal anomalies were detected (19.9%). The sensitivity of detection varied from 61.9% for malformations such as isolated hypoplastic left heart and single ventricle, to around 7-19% for atrial and ventricular septal defects. Prenatal detection rate of CHD was 11.4% for isolated cases, and 40.2% for multiple malformed with CHD. The gestational age at discovery varied from 16 to 36 weeks. There is no upper limit for termination of pregnancies in our country; 12.3% of all pregnancies were terminated after prenatal diagnosis. However, 62% of the pregnancies with a CHD detected prenatally were terminated. The detection rate of CHD increased during time from 9.2% during the period 1979-1988 to 13.7% during the period 1990-1993 and to 19.1% during the period 1994-1999. Our study shows large variation in the prenatal detection rate of CHD. Prenatal diagnosis of CHD is significantly higher when associated malformations are present. Cardiac defects affecting the size of the ventricles have the highest detection rate. Gestational age at discovery was 20-24 weeks for the majority of associated cardiac defects. The prenatal detection rate of CHD increased during time from 1979 to 1999.

Anomalies du fonctionnement thyroïdien des enfants trisomiques 21

Background. — Abnormal thyroid function was shown in children with Down syndrome (DS). This study was undertaken in order to specify these anomalies. Population and methods. — Thyroid function of 105 children with DS aged from 3 months to 20 years was studied by evaluation of serum concentration of thyrotropin, free T4 (FT4), free T3 (FT3) and reverse T3 (rT3). Each DS child was matched to a control of the same age. Results. — The mean concentration of thyrotropin of children with DS was increased while the mean concentration of rT3 of the DS children was significantly decreased compared with the controls, as was the ratio rT3TSH. When DS children are split into two groups, those with and those without increased thyrotropinemia, a significant decrease in the ratio rT3TSH appeared in DS children with increased thyrotropinemia whereas there is no difference between these two groups regarding to level of FT4, FT3, rT3 and zincemia. However, in all DS children serum zinc levels were lower than in controls. Thyrotropin levels rapidly normalized after thyroxin treatment. Conclusion. — One half of the children with DS have increased thyrotropinemia and all have a decreased rT3.

Prenatal detection of internal urinary system's anomalies A registry-based study

Prenatal diagnosis performed by ultrasound scan is now a routine part of antenatal care in our region. How many fetal anomalies are actually detected by this procedure? We have used our registry of congenital malformations to answer this question regarding to Internal Urinary System (IUS) anomalies. The mean time of detection of IUS anomalies was 29 weeks of pregnancy (12–39). The sensitivity of prenatal diagnosis of IUS anomalies by ultrasonographic examination was 59.3% for isolated malformations (fetuses with only one anomaly) and 46.0% for multiple malformed children with IUS anomalies. For all cases of IUS anomalies the percentage of prenatal detection was 56.0. Termination of pregnancy was performed in 9.4% of the cases.