[Effects, safety and cost-benefit analysis of Down syndrome screening in first trimester].

OBJECTIVE: To investigate the effects, safety and cost-benefit analysis of Down syndrome screening in first trimester. METHODS: From January 2009 to December 2012, 43 729 pregnant women undergoing 3 methods of Down syndrome traditional screening strategies in Shenzhen Maternity and Child Healthcare Hospital were studied retrospectively, including in 17 502 cases in pregnancy associated plasma protein A (PAPP-A) and free ß-hCG measured biochemistry screening, 14 080 cases in nuchal translucency (NT) screening and 12 147 cases in combined screening, meanwhile, 7 389 cases on non-invasive fetal trisomy test (NIFTY) were performed in Huada Gene Research Institute(BGI). The effects and safety of four screening strategies were assessed throughout a decision tree. The economical characters of each screening strategy were compared by cost-effectiveness analysis as well as cost-benefit analysis. RESULTS: (1) The effects of four strategies are: NIFTY > combined screening > NT screening > biochemistry screening. (2) The safety of four strategies are: NIFTY > combined screening > NT screening > biochemistry screening. (3) Cost-effectiveness analysis and cost-benefit analysis:the biochemistry screening has lowest cost-effectiveness ratio (CER) and highest cost-benefit ratio (CBR), which performed a better economical efficiency. The incremental CER of three traditional screening strategies are all less than the economical burden of Down syndrome.NIFTY has highest CER and negative net present value (NPV), NPV would be positive and CBR would be more than 1 if the price of NIFTY reduce to 1 434 Yuan. CONCLUSIONS: Combined screening possess best screening efficiency, while biochemistry screening was demonstrated more economical in traditional screening.NIFTY is the future of Down syndrome screening.

Can first-trimester screening program detect women at high risk for gestational diabetes mellitus?

This study was designed to compare first-trimester maternal serum biochemical markers of aneuploidy and fetal nuchal translucency in pregnancies complicated by gestational diabetes mellitus and those of a control group. The study included 60 gestational diabetic and 60 control women who attended the first-trimester combined screening program for Down syndrome between 11 and 14 gestational weeks with complete follow-up data and delivered in our institution. Maternal serum free ß-human chorionic gonadotropin, pregnancy-associated plasma protein-A and fetal nuchal translucency were investigated. The combined risks, double test risks and age risks were calculated by PRISCA software version 4.0. Comparison of the results between the two groups yielded no significant differences in serum levels of free ß-human chorionic gonadotropin and fetal nuchal translucency. However, women who developed gestational diabetes mellitus had significantly lower pregnancy-associated plasma protein-A. And also, the combined risks and double test risks calculated by PRISCA software were statistically higher in gestational diabetic women than normal pregnant women. These results suggest that differences can be seen between diabetic and healthy pregnant women in first-trimester maternal serum biochemical markers of aneuploidy.

Acoustic output as measured by thermal and mechanical indices during fetal nuchal translucency ultrasound examinations.

OBJECTIVE: Nuchal translucency (NT), performed between 11+0 and 13+6 weeks' gestation as part of a screening test for fetal chromosomal abnormalities, involves relatively steady ultrasound scanning of the fetus. The present study was aimed at measuring the acoustic output, as expressed by thermal index (TI) and mechanical index (MI), during routine NT examinations. METHODS: A prospective, observational study was conducted in patients undergoing routine NT screening. Examinations were performed between 11+0 and 13+6 weeks' gestation. Fetuses with anomalies were excluded from the analysis. Data were collected by an obstetrician, including duration of the examination, and each MI and TI during ultrasound examinations. Sonographers were unaware of the data being sought. RESULTS: A total of 50 ultrasound NT examinations were evaluated. Mean gestational age was 12.3 +/- 0.6 weeks. Mean duration of the ultrasound examination was 11.6 +/- 4.2 min. There were 109 variations of the TI during the examinations. Mean TI was 0.2 +/- 0.1; the median was 0.2, with a range of 0.1-0.7. There were 105 variations of the MI during the examinations. Mean MI was 1.1 +/- 0.1 (median 1.1, range 0.7-1.3). Mean NT was 1.4 +/- 0.4 mm. CONCLUSIONS: Acoustic exposure levels during NT ultrasound examination, as expressed by TI and MI, are generally low.

[Increased nuchal translucency with normal karyotype]. / Hyperclarté nucale à caryotype normal.

Nuchal translucency (NT) measurement in first trimester screening between 11 and 14 weeks' gestation has now been clearly identified as a marker for aneuploidies and in particular for trisomy 21. Even in the absence of aneuploidy increased fetal nuchal translucency has been shown to be a marker for fetal heart malformations and numerous other fetal defects and genetic syndromes when the measure is>or=95th centile which is around 3,5 mm for each gestational age. Fetuses with NT thickness above the 99th centile and normal karyotype have a high risk of adverse prenatal outcome and this increase in risk is exponential as the nuchal translucency measurement increases. However, among children born alive with normal ultrasound at 22 weeks of gestation, there was no significant association between NT thickness and development at 2 years as assessed by clinical examination and ASQ scores, when with a control population. Counselling should emphasize that when the karyotype is normal and no fetal structural malformation was missed prenatally following resolution of nuchal thickening, the prognosis is not impaired at the age of 2.