Maria L. Brizot

Fetal nuchal translucency: ultrasound screening for fetal trisomy in the first trimester of pregnancy

Objective To investigate a new method of screening for fetal trisomies on the basis of maternal age and fetal nuchal translucency thickness at 10 to 13 weeks of gestation.

Maternal serum hCG and fetal nuchal translucency thickness for the prediction of fetal trisomies in the first trimester of pregnancy

Objective To compare the potential value of maternal serum total hCG and free β‐hCG in predicting the risk for fetal trisomies during the first trimester of pregnancy and to examine whether data on maternal hCG and fetal nuchal translucency thickness can be combined to derive risks.

Crown-rump length in chromosomally abnormal fetuses at 10 to 13 weeks' gestation

OBJECTIVEnOur purpose was to investigate whether fetuses with aneuploidies demonstrate evidence of growth retardation during the first trimester.nnnSTUDY DESIGNnThis was a retrospective, cross-sectional study of singleton pregnancies undergoing fetal karyotyping at 10 to 13 weeks gestation. Measurements of crown-rump length in 135 chromosomally abnormal fetuses were compared with those in 700 chromosomally normal fetuses.nnnRESULTSnThe median crown-rump length of fetuses with trisomy 18 (n = 32) was significantly reduced. In contrast, in fetuses with trisomy 21 (n = 72), trisomy 13 (n = 11), 47,XXX (n = 6), 47,XXY (n = 6), 45,X (n = 5), and triploidy (n = 3) the crown-rump length was not lower than normal.nnnCONCLUSIONnAt 10 to 13 weeks gestation fetuses with trisomy 18 are growth retarded, whereas in trisomy 21, trisomy 13, and sex chromosome aneuploidy growth is normal.

First trimester maternal serum pregnancy‐associated plasma protein A and pregnancy‐specific βl‐glycoprotein in fetal trisomies

Objective To examine the potential value of maternal serum levels of pregnancy‐associated plasma protein A (PAPP‐A) and pregnancy‐specific βl‐glycoprotein (SP1) in the detection of fetal trisomy.

Gene expression of human pregnancy-associated plasma protein-A in placenta from trisomic pregnancies.

Placental pregnancy-associated plasma protein-A (PAPP-A) mRNA expression, placental PAPP-A protein concentration and maternal serum levels of PAPP-A were examined in pregnancies affected by trisomy 21 (n=8), trisomy 18 (n=7) and 15 normal controls at 12-15 weeks of gestation. The maternal serum concentration of PAPP-A in the trisomic group of pregnancies was significantly lower than in the normal controls. However there were no significant differences between the three groups in PAPP-A mRNA expression or PAPP-A protein concentration in the placental tissues. There was no significant association between the level of placental mRNA and either placental protein or maternal serum PAPP-A concentrations in the normal or trisomic pregnancies. There was however a significant association between placental protein and maternal serum PAPP-A concentrations in the normal and trisomy 21 pregnancies but not in those affected by trisomy 18. These findings suggest that the decrease in maternal serum PAPP-A in trisomic pregnancies is due to alternations in post-translational events such as protein stability, alterations in the release mechanism of the protein, impaired protein transport across the placenta or modified serum stability of PAPP-A.

Maternal serum Schwangerschafts protein-1 (SP1) and fetal chromosomal abnormalities at 10–13 weeks' gestation

Maternal serum SP1 concentration was measured at 10-13 weeks gestation in samples from 87 pregnancies with fetal chromosomal abnormalities (trisomy 21 n = 45; trisomy 18 n = 19; trisomy 13 n = 8; Turner syndrome n = 7; 47,XXX or 47,XXY n = 4; triploidy n = 4), and in samples from 348 matched controls. In the control group, SP1 increased significantly with fetal crown-rump length (r = 0.20, P < 0.0001) and there was no significant association with fetal nuchal translucency thickness (r = 0.03). Similarly, in the group with fetal chromosomal abnormalities, SP1 increased significantly with crown-rump length (r = 0.31, P < 0.01) and there was no significant association with nuchal translucency thickness (r = -0.08). In the groups with fetal trisomy 18 and trisomy 13, the median SP1 (0.76 MoM and 0.57 MoM, respectively) was significantly lower than in the controls (z = 2.64 and z = 3.27, respectively); in 21% and 25% of the cases, values were below the 5th centile. In the group with trisomy 21 and other chromosomal abnormalities the median SP1 (0.96 MoM and 0.93 MoM, respectively) was not significantly different from controls (z = 1.17 and z = 0.67, respectively). Measurement of SP1 concentration at 10-13 weeks gestation is not likely to be useful in the prediction of fetal chromosomal abnormalities.

First trimester maternal serum alpha‐fetoprotein in fetal trisomies

Objective To evaluate the potential value of maternal serum alpha‐fetoprotein concentration in the detection of fetal trisomy at 10 to 13 weeks gestation and to examine the possible association between maternal serum alpha‐fetoprotein and fetal nuchal translucency thickness.

Fetal hepatic alpha-fetoprotein mRNA expression in fetuses with trisomy 21 and 18 at 12–15 weeks gestation

In this study we examined alpha-fetoprotein (AFP) mRNA expression in fetal liver at 12-15 weeks of gestation in trisomy 21 (n = 13), trisomy 18 (n = 5) and control fetuses (n = 24). No significant difference was found in the steady-state level of fetal liver AFP mRNA levels in either of the two trisomy groups studied. These findings suggest that the decrease in maternal serum AFP concentration found in trisomic pregnancies is unlikely to be the consequence of impaired transcription of the AFP gene by the fetal liver.

Rapid detection of chromosome aneuploidies in fetal blood and chorionic villi by fluorescence in situ hybridisation

Objective Evaluation of fluorescence in situ hybridisation in the detection of numerical aberrations involving chromosomes X, Y, 13, 18 and 21.