C. Comas

FIRST‐TRIMESTER BIOCHEMICAL SCREENING FOR DOWN SYNDROME WITH THE USE OF PAPP‐A, AFP, AND β‐hCG

Biochemical screening for Down syndrome (DS) is well established in the second trimester of pregnancy, but there is little information available on its value in the first trimester. This study describes our preliminary results with biochemical screening for DS in the first trimester of pregnancy in order to evaluate its efficacy at this time. Our study population, including 19 DS pregnancies, was evaluated using maternal serum levels of α‐fetoprotein (AFP), β‐human chorionic gonadotropin (β‐hCG), and pregnancy‐associated plasma protein A (PAPP‐A). At a false positive rate (FPR) of 5 per cent, the detection rate (DR) for DS is 9 per cent for β‐hCG, 18 per cent for AFP, and 66 per cent for PAPP‐A when considering these parameters individually. With different combinations of the analytes, the best detection rates are obtained with the association of PAPP‐A and AFP (85 and 82 per cent DR for a 10 and 5 per cent FPR, respectively). Our data support the value of first‐trimester biochemical screening for DS and that of PAPP‐A as a single marker.

Doppler assessment of umbilical flow after genetic amniocentesis

The aim of our study was to evaluate the immediate changes on the fetal heart rate (FHR) and the fetal umbilical artery pulsatility index (UPI) after performing genetic amniocentesis. This was a prospective study including 431 consecutive singleton pregnancies between 14 and 18 weeks undergoing genetic amniocentesis in our institution. Doppler measurements were obtained transabdominally before and immediately after the procedure. Structural malformations detected by ultrasound were excluded. Students t-test was performed for comparisons among different groups and observed mean changes. The results showed a significant decrease in FHR post-amniocentesis (mean 1.5 beats, t = 3.47, P < 0.01) and a non-significant elevation in UPI (mean -0.01, t = -0.29, P = 0.77) after the procedure. Differences in FHR could be found when analyzed by each gestational week. These preliminary data suggest that although acute fetal hemodynamic changes are detected after genetic amniocentesis, such changes are unlikely to have clinical relevance. However, it is reasonable to propose the use of Doppler as a method of assessing hemodynamic effects caused by prenatal invasive procedures in order to provide more accurate in vivo research on this issue.

Bilateral Renal Agenesis and Cytomegalovirus Infection in a Case of Fraser Syndrome

A case of Fraser syndrome diagnosed prenatally is presented. Detection of oligohydramnios, hydrops fetalis and bilateral absence of the kidneys were the initial findings leading to further study. Specific IgM for cytomegalovirus in maternal serum and confirmed infection by fetal blood sampling was an associated finding. The importance of an etiologic diagnosis of nonimmune hydrops and the relevant aspects of genetic counselling are emphasized. The association of the Fraser syndrome with cytomegalovirus infection has not been previously reported.

Biochemical and Doppler predictors of poor perinatal outcome in a fetus with four umbilical vessels

Unexpected elevation of maternal serum alpha-fetoprotein (MSAFP) in women with anti-phospholipid syndrome has already been described as a predictor of fetal death. In this report we present a case of a pregnant woman with elevated second trimester MSAFP, in which Doppler ultrasound at 28 weeks suggested very poor fetal prognosis. A cesarean section was performed, but 2 days later the infant died due to distress. The only remarkable feature at post-mortem study was the finding of four vessels in the umbilical cord. Conventional investigation of the mother led us to the diagnosis of a primary anti-phospholipid syndrome. The finding of such an association should alert clinicians to the increased risk of fetal death. Precocious Doppler ultrasound examination may be the elective non-invasive technique to monitor such high risk fetuses.