Fetal cardiac abnormalities and their association with aneuploidy

Reference values for ductus venosus Doppler velocity indices between 11 and 13+6 weeks of gestation: A single-center prospective study in Iran

Background

This study aimed to investigate reference Doppler velocimetry indices (DVIs) of the fetal ductus venosus (DV) during 11-13 + 6 gestational weeks.

Materials and Methods

In a prospective observation over referrals to a single tertiary care center in a 2-year interval, normal singleton pregnancies with fetal crown-rump lengths (CRLs) of 43-80 mm were examined by a single experienced sonographer for their DV pulsatility index (DVPI), DV resistance index (DVRI), and S-wave maximum velocity/A-wave minimum velocity (S/A ratio). Multinomial and quantile regression functions were used to analyze the effect of gestational age (estimated by CRL) on reference values (5^th and 95^th percentiles of the distribution in each gestational day/week). P < 0.05 was considered significant.

Results

Over a sample of 415 participants with a mean/median gestational age of 12 + 1 weeks, no significant correlations were found between the CRL and DVIs using multinomial regression functions (linear model best fitted for all [DVPI: B coefficient = 0.001, P = 0.235] [DVRI: B coefficient = 0.001, P = 0.287] [DV S/A: B coefficient = 0.010, P = 283]). Quantile regression analyses of DVIs' reference values were nonsignificant across the CRL range except for the DVRI ([5^th regression line: coefficient = -0.004, P = 0.018] [95^th regression line: coefficient = -0.001, P = 0.030]).

Conclusion

Reference values for DVPI, DVRI, and DV S/A ratios were established as 0.80-1.39, 0.62-0.88, and 2.57-6.70, respectively. Future meta-analyses and multicenter studies are required to incorporate DV DVIs into an updated universal version of the practice.

Impact of fetal counseling on outcome of antenatal congenital surgical anomalies

AIM

To analyze the impact of counseling on antenatal congenital surgical anomalies (ACSA).

METHODS

Cases presenting with ACSA for fetal counseling and those presenting in post-natal period following diagnosis of ACSA (PACSA) for surgical opinion were analyzed for spectrum, presentation and outcome.

RESULTS

117 cases including ACSA(68);PACSA(49) were analyzed. Gestational age at diagnosis of ACSA;PACSA was 17-37;17-39 weeks (median 24;32 weeks). Diagnoses in ACSA;PACSA included urological (26;31), neurological (10;5), congenital diaphragmatic hernia (CDH)(5;1), gastrointestinal (5;5), lung and chest anomalies (5;1), intraabdominal cysts (4;1), abdominal wall defects (4;0), tumors (3;3), limb anomaly (1;1), esophageal atresia (1;1), conjoint twins (1;0), hepatomegaly (1;0), and major cardiac anomalies (2;0). Two antenatal interventions were done for ACSA; vesicoamniotic shunt and amnioinfusion for oligohydramnios. 17;24 ACSA;PACSA required early surgical intervention in post-natal period. Nine ACSA underwent medical termination of pregnancy and 4 had intrauterine demise. Nine ACSA babies died including two CDH, one gastroschisis, one duodenal atresia, one conjoint twins, one megacystitis with motility disorder and three posterior urethral valves. All PACSA babies survived.

CONCLUSION

Fetal counseling for CSA portrays true outcome of ACSA with 32.3% (22/68) mortality versus 0% for PACSA due to selection bias. However, fetal counseling ensures optimal perinatal care.

Investigating 22q11.2 deletion and other chromosomal aberrations in fetuses with heart defects detected by prenatal echocardiography

Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.

Evaluation of fetal heart rate variation during amniocentesis: correlation with fetal karyotype

OBJECTIVE

We monitored the fetal heart rate (FHR) during amniocentesis in fetuses at 16-18 weeks of gestation and investigated whether an abnormal FHR is associated with chromosomal abnormalities.

METHODS

This prospective study involves 807 women at 16-18 weeks of gestation who underwent genetic amniocentesis. The FHR, expressed as beats for minute, is recorded before (FHR1), immediately after (FHR2) and 60 min after (FHR3) the invasive procedure. Structural malformations detected by ultrasound and multiple pregnancy are excluded from the study.

RESULTS

Chromosomal abnormalities have been diagnosed in 27 fetuses. A mean FHR decrease after amniocentesis has been observed in normal and in abnormal fetuses. The mean variation during amniocentesis is significant in both groups (P < 0.01). The comparison between the mean FHR of the two groups shows no differences in FHR1 and FHR2 (P > 0.05) but a significant difference in FHR3 (P < 0.05).

CONCLUSION

The FHR decreases after amniocentesis; the decrease is larger in chromosomally abnormal fetuses than in normal fetuses. This difference in heart rate reaction to amniocentesis might be due to cardiac defects or developmental delay associated with the abnormal karyotype.

The influence of prenatal diagnosis on postnatal outcome in patients with structural congenital heart disease

Examination of the fetal heart has become an established part of mid-trimester anomaly scanning. Along side this has emerged the ability to diagnose congenital heart disease in the fetus with accuracy. Despite this, the development of screening programmes to look for fetal cardiac disease has only been partially successful. Furthermore, when detected, there seems to be little survival advantage associated with prenatal diagnosis. Demonstrating such an advantage is complicated by the nature of fetal cardiac disease, which tends to be severe and is often associated with extra-cardiac abnormalities. More selective studies, mostly involving small numbers of cases, are now beginning to demonstrate both improved survival and reduced morbidity in prenatally diagnosed infants presenting to cardiac intensive care units compared to those with a postnatal diagnosis.

Congenital heart disease and aneuploidy

Congenital heart disease (CHD) is one of the commonest prenatal diagnoses made on routine ultrasound screening. Overall, up to 33% of CHD are associated with fetal aneuploidy. However, some specific cardiac lesions have a significantly greater association with particular chromosomal abnormalities. The majority of fetuses with CHD and aneuploidy also have extra-cardiac anomalies and are best managed by a multidisciplinary team where the management and prognosis of the cardiac defect can be discussed in the context of the baby as a whole. It is therefore important for clinicians involved in the management of fetuses with CHD to be aware of the association of aneuploidy as well as the prognosis and management of these cases, so that they can appropriately counsel the parents. In this chapter, we review the frequency and types of aneuploidy associated with the commonly diagnosed CHD and discuss their management.

Prenatal diagnosis and management of fetal cardiovascular malformations

Screening for fetal cardiovascular malformations is widely performed. Its accuracy is not yet satisfactory, but better training of ultrasonographers and extension from the four-chamber view to the study of the outflow tract are probably clues to an improvement. The main impact of prenatal diagnosis is still the termination of pregnancy for severe malformations and for those associated with chromosomal or extracardiac anomalies. There is now evidence that prenatal diagnosis improves perinatal morbidity or mortality for some malformations. New information about the molecular genetic basis of congenital heart disease will help in management and counselling.