Anxiety in women with low maternal serum alpha-fetoprotein screening results

The purpose of this study was to measure anxiety in pregnant women who had low maternal serum alpha-fetoprotein (MSAFP) screening test levels, received genetic counselling and chose to undergo amniocentesis for fetal chromosome analysis. Their anxiety levels were compared with the levels in women undergoing amniocentesis because of advanced maternal age. The results indicate a higher level of anxiety in women with low alpha-fetoprotein (AFP) levels.     

Prenatal diagnosis of smith–lemli–opitz syndrome is possible by measurement of 7-dehydrocholesterol in amniotic fluid

Amniocentesis was performed at 17.3 weeks in a pregnancy with severe intrauterine growth retardation. Cytogenetic studies on amniocytes were normal, 46,XX, and the pregnancy was continued. The diagnosis of Smith–Lemli–Opitz syndrome was suspected in the neonatal period and confirmed by the presence of 7-dehydrocholesterol (7-DHC) in the plasma (0.4 mmol/l, normal = not detectable) associated with a low total cholesterol concentration (0.4 mmol/l, normal = 2.56 ± 0.23). Retrospective analysis of the amniotic fluid sample revealed an elevated level of 7-DHC (0.022 mmol/l; normal = undetectable). Therefore measurement of 7-DHC levels in amniotic fluid during the second trimester of pregnancy is useful for the prenatal diagnosis of Smith–Lemli–Opitz syndrome in families at risk and should be considered in cases of severe growth retardation of unknown aetiology for which amniotic fluid is available and in which a normal chromosomal pattern in amniocytes is present.     

Adjustment formulae for maternal serum alpha-fetoprotein,human chorionic gonadotropin,and unconjugated oestriol to maternal weight and smoking

Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and un-conjugated oestriol (uE3) were measured in serum samples of 4131 non-smoking and 1018 smoking women during the second trimester of pregnancy. The levels of all three analytes decreased with increasing body weight. The AFP median was significantly increased in smokers in a dose-response association; hCG decreased by 21 per cent and uE3 decreased by 3 per cent in smokers in a non-dose-related fashion. Regression functions for adjustment of serum levels for weight and smoking should be considered in risk estimation for Down syndrome in order to give a woman's individual risk more precisely.     

Bilateral renal agenesis in three consecutive siblings

We report here an unusual recurrence of bilateral renal agenesis (BRA) in three consecutive siblings. Chromosome analysis was normal, as were renal ultrasound studies on both parents and their surviving child. Ultrasound was employed prenatally to diagnose Potter's syndrome in both of the recurrences, and autopsy confirmed BRA in otherwise normal fetuses. Recurrence of BRA points to the usefulness of ultrasound in monitoring subsequent pregnancies in couples who have had one such occurrence. Ultrasound studies should also be performed in non-affected family members to detect the presence of asymptomatic anomalies of the genitourinary system, but a negative family study does not preclude recurrence of BRA.     

Maternal serum free β-human chorionic gonadotrophin levels in twin pregnancies: Implications for screening for down's syndrome

Free β-human chorionic gonadotrophin values are, on average, 1·90 times greater in twin pregnancies than in singleton pregnancies [95 per cent confidence interval (CI) 1·69–2·13]. This information can be used in screening for Down's syndrome, so that twin pregnancies can be interpreted in addition to singleton pregnancies.     

Tetrasomy 12p (Pallister-Killian syndrome): Ultrasound indicators and confirmation by interphase fish

Tetrasomy 12p (Pallister-Killian syndrome) is a mosaic aneuploidy syndrome in which the isochromosome is present in amniocytes with a much greater percentage than fetal lymphocytes. Two new cases identified by prenatal diagnosis are reported. Indications for prenatal diagnosis were advanced maternal age and fetal anomalies. The most consistent reported prenatal ultrasound findings for tetrasomy 12p include polyhydramnios with short femurs and a diaphragmatic hernia. Recognition of congenital malformation patterns prenatally may allow appropriate selection of tissue for chromosome analysis. Molecular cytogenetic analysis using fluorescence in situ hybridization was used retrospectively to confirm the presence of the isochromosome 12p in various formalin-fixed fetal tissues. The levels of mosaicism detected in fetal and placental tissues were lower than those detected prenatally.     

First-trimester maternal serum schwangerschafts protein 1 (SP1) in pregnancies associated with chromosomal anomalies

The relationship between first-trimester maternal serum Schwangerschafts protein 1 (SP1) and the karyotype of the pregnancy was examined in 692 women who underwent chorionic villus biopsy at 6–12 weeks. There were 30 pregnancies with abnormal karyotypes, consisting of 14 Down's syndrome (DS), eight trisomy 18, and eight other anomalies, two of which were mosaics. The normal ranges and medians for gestation were defined from the 662 cases in which the karyotype was normal. The median SP1 (0·5 MOM) of the abnormal group was significantly lower than that of the normal group (10 MOM). This relationship was maintained for the DS pregnancies (0·4 MOM) and for anomalies other than trisomy 18 (0·43 MOM) but not trisomy 18 (1·1 MOM). It is possible that the use of SP1 as a screening test for chromosome anomalies in the first trimester could have a 43 per cent detection rate for a 5 per cent false-positive rate.     

Normal fetal growth in women with antiphospholipid syndrome treated with high-dose intravenous immunoglobulin (IVIG)

Antiphospholid antibodies are associated with fetal distress and fetal death. Although different therapeutic regimens have been used, the incidence of fetal growth retardation varies between 30 and 60 per cent of reported cases. We report the evolution of fetal growth in patients with antiphospholipid antibody syndrome treated with high-dose intravenous immunoglobulins (IVIG). Fourteen patients with a history of recurrent spontaneous abortion and immunological diagnosis of antiphospholipid syndrome were followed longitudinally. Intravenous immunoglobulin at a dose of 0.5 g/kg body weight for two consecutive days was started from the fifth week of pregnancy and repeated every 4 weeks until the 33rd week of gestation. Fetal biometry was evaluated longitudinally from the appearance of the gestational sac at 4 weekly intervals. In the period between 26 and 34 weeks, the frequency of evaluation was increased to every 14 days. Data obtained were compared with a control group of 70 fetuses with uneventful pregnancies matched for gestational age. Neonatal weight is shown in relation to the centiles for the normal population. One patient out of 14 (7.1 per cent) developed gestational hypertension and abruptio placentae. No other pregnancy complications were seen. No proteinuria was found. The mean maternal age was 31.2±3.8 years. Median birth weight was 3433 g±287. The median centile of the birth weight was 65.3±18.6. Mean gestational age at delivery was 1.3 weeks. No fetal or neonatal growth retardation was seen. No significant differences were found in the biometrical parameters investigated in the various gestational ages vs. the control group (Student's t-test not significant); a significant increase in head circumference (P< 0.001) and abdominal circumference (P< 0.05) was found at 36–37 weeks gestational age in the IVIG-treated fetuses. The presence of antiphospholipid antibodies is considered detrimental for pregnancy outcome because of their negative effects on placental vascular perfusion and fetal transfer of metabolites. The use of IVIG seems to avoid or inhibit the reduced availability of nutrients for the fetal anabolic functions, as the expected reduction in fetal growth was not seen in our series.     

Maternal smoking habits and Down's syndrome

Two series of pregnancies were studied to investigate the relationship between maternal smoking and the risk of fetal Down' s syndrome. In the first series, ascertained in the 1960s, in which smoking habits were determined after the outcome of pregnancy was known, the proportion of smokers (47 per cent) among the 461 women whose pregnancies ended in the birth of an infant with Down' s syndrome was similar to that in the 461 controls (46 per cent) who had pregnancies affected by other congenital disorders. In the second series, ascertained between 1973 and 1984, smoking habits were determined by measurement of cotinine in antenatal serum samples that were routinely collected and stored or, if a serum sample was not available, from information in the antenatal notes. In this series, the proportion of smokers (14 per cent) among the 91 women who had pregnancies associated with Down' s syndrome was lower than that among 413 controls (19 per cent), though this was not statistically significant. Collectively, our results provide no evidence for an association between fetal Down' s syndrome and smoking. Other published studies found a deficit of smokers among women who had pregnancies associated with Down' s syndrome. This may be partly due to some studies not taking adequate account of maternal age (older women are more likely to have had a Down' s syndrome pregnancy but are less likely to be smokers) and partly due to the greater tendency for positive findings to be published than negative ones.