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Objective: To investigate first trimester levels of ADAM12 in trisomy 18 and 13 pregnancies and whether incorporating ADAM12 in the LifeCycle™ risk calculation program of trisomy 18 and trisomy 13 screenings can improve the detection rates of trisomies 18 and 13., Methods: ADAM12 was incorporated in the LifeCycle™ risk calculation program. A specific algorithm with cut-off of 1:200 for screening of trisomies 18 and 13 was employed. Detection rates for trisomies 18 and 13 were calculated., Results: There was a significant difference in ADAM12 levels between trisomy 18 pregnancies and controls during the gestation weeks 9 + 0 - 10 + 6, but not thereafter. In trisomy 13 pregnancies there was no difference in weeks 9 + 0 - 10 + 6, but there was in 11 + 0 - 12 + 6. The specific algorithms for trisomies 18 and 13 combined with algorithm for trisomy 21 yielded detection rates of 73.7% and 66.7%, respectively. The combined false positive rate was 4.6%. Adding ADAM12, the detection rate for trisomy 18 was the same, at 73.7% and for trisomy 13, at 66.7%., Conclusion: ADAM12 did not improve the detection rate.

We analyzed the frequency and possible causes of false-negative (Fn) screening results in first-trimester combined Down syndrome screening in Finland. During the study period (May 1, 2002, to December 31, 2008), 76,949 voluntary women with singleton pregnancies participated in screening. Maternal age at screening, week of gestation, levels of pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (fβ-hCG), and nuchal translucency (NT) measurement were compared and statistically analyzed between true-positive (Tp) and Fn cases. There were a total of 188 Down syndrome cases (1:409) in the screened population; 154 confirmed Tp and 34 Fn cases. Most Fn cases (n = 25) occurred at 12 + 0 to 13 + 6 weeks' gestation and only nine Fn cases presented between 10 and 11 weeks' gestation. According to the logistic regression analysis, the NT measurement was the most powerful discriminating factor in Fn screening results and accounted for 37.2% of Fn results. The second most important factor was fβ-hCG, adding 14.0% to R(2), followed by PAPP-A, which contributed a further 14.3%. The chosen parameters explain 83.9% of Fn results, but 16.1% remain due to unknown factor(s). All investigated parameters contributed to Fn screening results, but fetal NT was the most discriminating factor leading to an Fn screening result., (Copyright © 2012 by Thieme Medical Publishers, Inc.)

Objective: To examine the performance of first-trimester combined screening after adding the specific algorithms for trisomies 18 and 13 in the Down syndrome screening program for chromosomal abnormalities other than trisomy 21 and to determine the outcomes of such pregnancies., Design: A retrospective study., Setting: Oulu University Hospital, Finland., Population: Pregnant women (n=56 076) participating voluntarily in first-trimester combined Down syndrome screening in Northern and Eastern Finland during the study period 1 June 2002 to 31 December 2008., Methods: The data of all known cases of chromosomal abnormalities other than trisomy 21 were collected., Main Outcome Measures: Risk algorithms for trisomies 21, 18 and 13 were used for the calculation of patient-specific risks for certain chromosomal abnormalities. Algorithms were based on maternal age, crown-rump length, nuchal translucency, and measurement of free β-human chorionic gonadotrophin and pregnancy-associated plasma protein-A. Detection rates and false-positive rates were calculated., Results: A total of 27 cases of trisomy 18, 11 cases of trisomy 13 and 30 cases of other chromosomal abnormalities were analyzed. The algorithm for Down syndrome detected 55.6% of trisomy 18 cases, 36.4% of trisomy 13 cases and 60.0% of other chromosomal abnormalities. When specific risk algorithms were added, the detection rates improved for trisomy 18 (74.0%) and for trisomy 13 (54.5%), with only a slight increase of the false-positive rate of 0.2%. The detection rate for other chromosomal abnormalities did not improve., Conclusions: Adding the trisomy 18 algorithm to the Down screening program resulted in the detection of five additional trisomy 18 cases., (© 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.)

Objective: To evaluate the performance of first-trimester combined screening in 5-year periods according to maternal age in a low-risk population., Design: A prospective study., Setting: Multicenter study in Finland., Population: A total of 76949 voluntary women with singleton pregnancies participated in first-trimester combined screening in public healthcare between 1 May 2002 and 31 December 2008., Methods: The serum samples were analyzed using the PerkinElmer AutoDELFIA® time-resolved fluoroimmunoassay kit for the measurement of pregnancy-associated plasma protein-A and free beta-human chorionic gonadotropin. Nuchal translucency was measured by trained personnel (midwives or physicians) in a university or central hospital., Main Outcome Measures: Performance, detection rate, false positive rate and the number of invasive procedures needed to detect a single case of Down's syndrome were analyzed., Results: There was a direct connection between maternal age and the prevalence of Down's syndrome with a low prevalence in young women being 1:1 193 in the 25-29 age group and 1:150 in the 35-39 age group. Consequently, for a fixed false positive rate of 5%, the number of invasive procedures needed to detect one case of Down's syndrome is higher in younger women to achieve the same detection rate., Conclusions: In combined first trimester screening the risk for Down's syndrome is individual, varying with maternal age. This should be taken into consideration when counseling women., (© 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.)

Objectives We evaluated the performance of first trimester screening for Down syndrome in women less than 35 years of age (study group) and in women aged 35 years or more (control group) in an unselected low-risk population. Methods The study group comprised a total of 63 945 women who participated in the first trimester combined screening in public health care in Finland during the study period of 1 May 2002 to 31 December 2008. Women at the age of 35 or more ( n = 13 004) were controls. Prevalence of Down syndrome, detection rate, false positive rate and number of invasive procedures needed to detect a single case of Down syndrome were analyzed in both groups. Results The overall prevalence of Down syndrome ( n = 73) in the study group was 1:876. The number of detected cases was 54. The detection rate was 74.0% with a false positive rate of 2.8%. Number of invasive procedures needed to detect a single case of Down syndrome was 33. In the control group, the detection rate was 87.0% with a false positive rate of 11.9%. The number of invasive procedures needed to detect a single case of Down syndrome was 15. The differences in detection rate and false positive rate were significant, P < 0.012, P < 0.001, respectively. Conclusion The overall detection rate given for the entire population is an overestimate for a woman younger than the age of 35, which should be taken into consideration when counselling women of that age. [ABSTRACT FROM AUTHOR]