Cardiac flow after fetal blood sampling in normally grown and growth-retarded fetuses

The objective of this study was to evaluate the effect of fetal blood sampling on cardiac flow velocity waveforms. Flow velocity waveforms were measured from the ascending aorta and pulmonary artery immediately before and after fetal blood sampling in 29 normally grown and 12 growth-retarded fetuses. The latter group was characterized by abnormal Doppler indices in the umbilical artery and middle cerebral artery suggestive of uteroplacental insufficiency as the causative factor of the impaired growth. The flow velocity parameters studied were the peak velocity, the time to peak velocity, and the left and right cardiac output and their ratio. In normally grown fetuses, the peak velocity and right and left cardiac output values increased significantly after fetal blood sampling, while no significant changes were observed in the other indices considered. The gestational age at the time of the procedure was positively related to the amplitude of these changes. In growth-retarded fetuses, fetal blood sampling did not induce any significant increase in cardiac output or peak velocities, while in more than 50 per cent of the fetuses these Doppler indices decreased. The amplitude of the decrease was significantly related to the severity of acidosis in the umbilical vein. In conclusion, the cardiac haemodynamic response to fetal blood sampling differs between normally grown and growth-retarded fetuses. This difference may explain the higher rate of complications occurring in the latter group of fetuses after blood sampling.     

Methylenetetrahydrofolate reductase deficiency: Prenatal diagnosis and family studies

Prenatal diagnosis of methylenetetrahydrofolate reductase (MTHFR) deficiency and family studies were performed because of a severely affected first child in this family. The fetus at risk was found to be heterozygous as confirmed by the enzymatic activity assay performed several times after birth. In the father, MTHFR activity was normal in lymphocytes and decreased in fibroblasts, whereas in the asymptomatic mother, the activity was not detectable in fibroblasts and was very low in lymphocytes. The absence of any clinical symptoms in the mother despite a clear MTHFR deficiency and hyperhomocystinemia emphasizes the heterogeneity of this disease.     

Do racial differences exist in second-trimester maternal hCG levels? a study of 23 369 patients

In Down syndrome screening by maternal serum human chorionic gonadotropin (hCG) determination at 15, 16, 17, and 18 weeks of gestation, we prospectively examined 23 369 sera from white (21 549), North African (970), black African (525), and Asian (325) patients. When expressed as multiples of the median (MOM), no difference was observed between white, North African, and black African patients. However, higher serum hCG concentrations were noted in Asians, for whom we therefore recommend correction of hCG values before calculation of the risk of Down syndrome.     

Prenatal sonographic appearance of foramina parietalia permagna

Foramina parietalia permagna (FPP) is an extremely uncommon congenital defect, inherited as an autosomal dominant condition. Its characteristics are two symmetrical orifices in the parietal bones (not of fixed size) on both sides of the midline. This defect does not affect either the psychic or the physical development of the affected person. This paper describes the sonographic appearance of FPP in utero as an enlargement of the posterior fontanelle.     

Elevated mid-trimester hCG and maternal lupus anticoagulant

An association is described between women with lupus anticoagulant and abnormal prenatal serum screening results. Three cases of positive second-trimester serum screening for Down syndrome, with karyotypically normal fetuses, in women demonstrated to have lupus anticoagulant are presented. Serum screening positivity was principally due to a disproportionately elevated maternal serum human chorionic gonadotrophin (hCG) level. In each case, early, severe intrauterine growth restriction was documented, with only one fetus surviving the neonatal period. As maternal lupus anticoagulant may have a profoundly adverse effect on the course of pregnancy, we suggest that an elevated hCG level on prenatal screening prompt consideration of maternal lupus anticoagulant testing if ultrasonography demonstrates an otherwise normal singleton gestation and the fetal karyotype is normal.     

Prenatal ultrasonographic diagnosis of congenital megalourethra

Congenital megalourethra is a rare genital anomaly characterized by dilatation of the penile urethra without evidence of distal obstruction. Reports of the prenatal diagnosis of this condition in the literature are limited. We present a case of congenital megalourethra with obstructive uropathy from the posterior urethra diagnosed prenatally at 18 weeks of gestation. ‘Prune-belly’-like features, colonic malrotation, and imperforate anus were also found on autopsy.     

Hereditary multiple intestinal atresia—ultrasound findings and outcome of pregnancy in an affected case

A case of multiple intestinal atresia is described. Dilatation of the bowel was observed at 17 weeks' gestation during routine ultrasound scan of a healthy Caucasian primigravida from a non-consanguineous marriage. Amniocentesis was performed. The karyotype was normal male and cystic fibrosis screening was negative. Regular scans were performed throughout the pregnancy and a simple bowel obstruction was suspected. The baby was delivered at 37 weeks' gestation in good condition. Initial clinical examination was normal but abdominal distension developed during the first day. At laparotomy, prepyloric septal atresia, a distal duodenal membrane, and multiple intestinal atresia were found. The baby died aged 4 days. Post-mortem examination of the abdomen confirmed the absence of lumen from long segments of the small intestine together with areas of colonic atresia. Histology and distribution were consistent with those reported in familial multiple intestinal atresia. The pitfalls in the interpretation of prenatal ultrasound scans and the possibility of prenatal diagnosis in future pregnancies are discussed.     

The importance of late pregnancy scans for renal tract abnormalities

A 12-month prospective population study of antenatal patients was undertaken in a large district general hospital to assess ultrasound scanning in late pregnancy for the detection of non-lethal fetal renal abnormalities. The rate of false-negative antenatal scans during the study period was also assessed. Both 18–20 and 28–32 weeks' gestational scans were performed on 6497 pregnant women. Forty fetuses with a suspected abnormality were referred for postnatal examination and 29 neonates were found to have renal abnormalities. Of these, 21 were significant and eight were likely to be extrarenal pelves. In six, there was evidence of an abnormality at the early scan. Nine children, seven with reflux, presented within the study period, all with preceding normal antenatal scans. The incidence (0·46 per cent) of structural renal abnormalities is similar to that reported previously. A late scan is necessary for the antenatal detection of non-lethal renal abnormalities.     

Early invasive prenatal diagnosis in HBsAg-positive women

From 1982 to 1989, pregnant women in two large city hospitals in The Netherlands had serum samples screened for hepatitis B surface antigen (HBsAg). Infants of mothers found to be HBsAg-positive received hepatitis B immune globulin immediately after birth and hepatitis B vaccine in the first year of life. Blood samples of infants were regularly tested for HBsAg and antibodies directed against HBsAg. A retrospective analysis of the pregnancy outcome in HBsAg-positive women who had invasive tests for prenatal diagnosis was carried out to determine whether amniocentesis and chorionic villus sampling (CVS) are risk factors for the intrauterine transmission of the hepatitis B virus. Amniocentesis was carried out in 17 HBsAg-positive women and CVS in one case. Only two women were HBsAg- and HBeAg-positive. Prenatal diagnosis led to the termination of pregnancy for fetal chromosome abnormality in three cases. The remaining 15 pregnancies were uneventful; all infants were negative for HBsAg and developed an active immune response to the vaccine. These data suggest that amniocentesis in HBsAg-positive women constitutes a low risk for the intrauterine transmission of the hepatitis B virus, but definite conclusions in HBeAg-positive women cannot be drawn.