Cell-free fetal DNA versus maternal serum screening for trisomy 21 in pregnant women with and without assisted reproduction technology: a prospective interventional study.

PURPOSE: Cell-free DNA (cfDNA) as a primary screening test has been available for years but few studies have addressed this option in a prospective manner. The question is of interest after reports that maternal serum screening (MSS) is less accurate for pregnancies resulting from assisted reproduction technologies (ART) than for spontaneous pregnancies (SP). METHODS: A prospective interventional study was designed to address the performances of cfDNA compared with MSS in pregnancies with or without ART. Each patient was offered both MSS and cfDNA testing. The primary analysis cohort ultimately included 794 patients with a spontaneous pregnancy (SP) (n = 472) or pregnancy obtained after ART (n = 322). RESULTS: Overall, the false-positive rate and positive predictive value were 6.6% and 8.8% for MSS but 0% and 100% for cfDNA. MSS false-positive rate and positive predictive values were clearly poorer in the ART group (11.7% and 2.6%) than in the SP group (3.2% and 21.1%). The global rates of invasive procedures were 1.9% (15/794) with cfDNA but 8.4% (65/794) if MSS alone was proposed. CONCLUSION: cfDNA achieved better performance than MSS in both spontaneous and ART pregnancies, thus decreasing the number of invasive procedures. Our findings suggest that cfDNA should be considered for primary screening, especially in pregnancies obtained after ART.

Biochemical analysis of ascites fluid as an aid to etiological diagnosis: a series of 100 cases of nonimmune fetal ascites.

OBJECTIVE: The aim of this study is to analyze the contribution of biochemistry and cytology of fetal ascites fluid to the etiological diagnosis of ascites after ultrasonographic scan, maternal blood sampling, and fetal karyotyping. METHOD: This is a retrospective study of 100 consecutive cases of nonimmune fetal ascites in which ascites fluid was sampled. All women underwent referral ultrasound scan and fetal karyotyping. All cases of fetal ascites were studied by biochemistry (total protein, ß2 -microglobulin, IgM, gamma-glutamyl transpeptidase, aspartate aminotransferase, aminopeptidase M, and intestinal isoform of alkaline phosphatase) and cytology (lymphocyte count and vacuolated cells). RESULTS: The etiology of ascites was diagnosed at ultrasound scan in only 50% of cases. We observed significantly (P < 0.001) low levels of total protein in ascites of urinary origin, high levels of digestive enzymes in ascites of digestive origin, and high ß2 -microglobulin in infectious ascites. Vacuolated cells were observed in all ten storage metabolic diseases. CONCLUSION: Sampling of fetal ascites fluid for biochemical and cytological examination provides important additional information. We propose a two-step management: (1) detailed ultrasound scan examination, maternal blood analysis, and fetal karyotyping and (2) biochemical and cytological analyses. On the basis of such an approach, 63% and 96% of etiologies would have been identified in our series after the first and second steps, respectively. © 2014 John Wiley & Sons, Ltd.