1. Obstetrical complications associated with abnormal maternal serum markers analytes
Alain Gagnon, et al. J Obstet Gynaecol Can. 2008 Oct;30(10):918-932. doi: 10.1016/S1701-2163(16)32973-5.
Objective: To review the obstetrical outcomes associated with abnormally elevated or decreased level of one or more of the most frequently measured maternal serum marker analytes used in screening for aneuploidy. To provide guidance to facilitate the management of pregnancies that have abnormal levels of one of more markers and to assess the usefulness of these markers as a screening test. Options: Perinatal outcomes associated with abnormal levels of maternal serum markers analytes are compared with the outcomes of pregnancies with normal levels of the same analytes or the general population.
2. Using record linkage and manual follow-up to evaluate the Victorian maternal serum screening quadruple test for Down's syndrome, trisomy 18 and neural tube defects
Alice M Jaques, Veronica R Collins, Kerry Haynes, Leslie J Sheffield, Ivan Francis, Robin Forbes, Jane L Halliday J Med Screen. 2006;13(1):8-13. doi: 10.1258/096914106776179782.
Objectives: The Genetic Health Services Victoria maternal serum screening (MSS) quadruple test has been available to pregnant women in Victoria since 1996. The objectives of this study were to follow up the pregnancies screened by MSS between July 1998 and June 2000 and to determine the performance characteristics of the test for Down's syndrome, trisomy 18 and neural tube defects (NTDs). Methods: MSS results were matched to pregnancy outcome information from the Perinatal Data Collection Unit and Birth Defects Register, using automated probabilistic record linkage. For unmatched pregnancies, manual follow-up was carried out by contacting referring doctors and hospitals, resulting in a very high follow-up rate of 99.2% (18,989/19,143). Results: The sensitivity of MSS for Down's syndrome was 85% (23/27-95%CI 72-99%) with a falsepositive rate (FPR) of 6.8% (risk threshold >or= 1 in 250). While using a fixed 5% FPR, the sensitivity for Down's syndrome was slightly lower (78%). The sensitivity for trisomy 18 was 44% (4/9 - 95% CI 12-77%) with a FPR of 0.5% (risk threshold of >or= 1 in 200). 11 of the 15 (73 - 95%CI 51-97%) cases of open NTDs were detected from screening, with a 1% FPR (risk threshold alpha-fetoprotein [AFP] >or=2.5 MoM). All cases of anencephaly had increased AFP levels. Conclusion: Probabilistic record linkage and manual follow-up is an efficient method for ascertainment of pregnancy outcomes, with a higher follow-up rate than that reported in similar studies. MSS should remain an available option for all pregnant women in Victoria, with test characteristics comparable with other recent reports of the quadruple test.
3. Prenatal screening for fetal aneuploidy in singleton pregnancies
David Chitayat, et al. Practice J Obstet Gynaecol Can. 2011 Jul;33(7):736-750. doi: 10.1016/S1701-2163(16)34961-1.
Objective: To develop a Canadian consensus document on maternal screening for fetal aneuploidy (e.g., Down syndrome and trisomy 18) in singleton pregnancies. Options: Pregnancy screening for fetal aneuploidy started in the mid 1960s, using maternal age as the screening test. New developments in maternal serum and ultrasound screening have made it possible to offer all pregnant patients a non-invasive screening test to assess their risk of having a fetus with aneuploidy to determine whether invasive prenatal diagnostic testing is necessary. This document reviews the options available for non-invasive screening and makes recommendations for Canadian patients and health care workers.
