https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(97)11280-6.pdf

UK multicentre project on assessment of risk of trisomy 21 by maternal age and fetal nuchal-translucency thickness at 10-14 weeks of gestation

background It is uncertain how best to screen pregnant women for the presence of fetal Down’s syndrome: to perform first-trimester screening, to perform second-trimester screening, or to use strategies incorporating measurements in both trimesters. methods Women with singleton pregnancies underwent first-trimester combined screening (measurement of nuchal translucency, pregnancy-associated plasma protein A [PAPP-A], and the free beta subunit of human chorionic gonadotropin at 10 weeks 3 days through 13 weeks 6 days of gestation) and second-trimester quadruple screening (measurement of alpha-fetoprotein, total human chorionic gonadotropin, unconjugated estriol, and inhibin A at 15 through 18 weeks of gestation). We compared the results of stepwise sequential screening (risk results provided after each test), fully integrated screening (single risk result provided), and serum integrated screening (identical to fully integrated screening, but without nuchal translucency). results First-trimester screening was performed in 38,167 patients; 117 had a fetus with Down’s syndrome. At a 5 percent false positive rate, the rates of detection of Down’s syndrome were as follows: with first-trimester combined screening, 87 percent, 85 percent, and 82 percent for measurements performed at 11, 12, and 13 weeks, respectively; with second-trimester quadruple screening, 81 percent; with stepwise sequential screening, 95 percent; with serum integrated screening, 88 percent; and with fully integrated screening with first-trimester measurements performed at 11 weeks, 96 percent. Paired comparisons found significant differences between the tests, except for the comparison between serum integrated screening and combined screening. conclusions First-trimester combined screening at 11 weeks of gestation is better than secondtrimester quadruple screening but at 13 weeks has results similar to second-trimester quadruple screening. Both stepwise sequential screening and fully integrated screening have high rates of detection of Down’s syndrome, with low false positive rates.

/pdf/first-trimester-or-second-trimester-screening-or-both-for-175if8oz9r.pdf

First-trimester or second-trimester screening, or both, for down's syndrome

Background—The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and manage...

/pdf/diagnosis-and-treatment-of-fetal-cardiac-disease-a-1komqhwbxf.pdf

Diagnosis and Treatment of Fetal Cardiac Disease A Scientific Statement From the American Heart Association

Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities.

Effective screening for major aneuploidies can be provided in the first trimester of pregnancy. Screening by a combination of fetal nuchal translucency and maternal serum free-β-human chorionic gonadotrophin and pregnancy-associated plasma protein-A can identify about 90% of fetuses with trisomy 21 and other major aneuploidies for a false-positive rate of 5%. Improvement in the performance of first-trimester screening can be achieved by firstly, inclusion in the ultrasound examination assessment of the nasal bone and flow in the ductus venosus, hepatic artery and across the tricuspid valve, and secondly, carrying out the biochemical test at 9 to 10 weeks and the ultrasound scan at 12 weeks.

https://obgyn.onlinelibrary.wiley.com/doi/epdf/10.1002/pd.2637

Screening for fetal aneuploidies at 11 to 13 weeks

OBJECTIVE--To examine the significance of fetal nuchal translucency at 10-14 weeks' gestation in the prediction of abnormal fetal karyotype. DESIGN--Prospective screening study. SETTING--The Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London. SUBJECTS--827 fetuses undergoing first trimester karyotyping by amniocentesis or chorionic villus sampling. MAIN OUTCOME MEASURE--Incidence of chromosomal defects. RESULTS--The incidence of chromosomal defects was 3% (28 of 827 cases). In the 51 (6%) fetuses with nuchal translucency 3-8 mm thick the incidence of chromosomal defects was 35% (18 cases). In contrast, only 10 of the remaining 776 (1%) fetuses were chromosomally abnormal. CONCLUSION--Fetal nuchal translucency > or = 3 mm is a useful first trimester marker for fetal chromosomal abnormalities.

https://www.bmj.com/content/bmj/304/6831/867.full.pdf

K. Marks

Papers

Fetal nuchal translucency: ultrasound screening for chromosomal defects in first trimester of pregnancy.