First trimester screening for pre-eclampsia and targeted aspirin prophylaxis: a cost-effectiveness cohort study.

OBJECTIVE: Investigate cost-effectiveness of first trimester pre-eclampsia screening using the Fetal Medicine Foundation (FMF) algorithm and targeted aspirin prophylaxis in comparison with standard care. DESIGN: Retrospective observational study. SETTING: London tertiary hospital. POPULATION: 5957 pregnancies screened for pre-eclampsia using the National Institute for Health and Care Excellence (NICE) method. METHODS: Differences in pregnancy outcomes between those who developed pre-eclampsia, term pre-eclampsia and preterm pre-eclampsia were compared by the Kruskal-Wallis and Chi-square tests. The FMF algorithm was applied retrospectively to the cohort. A decision analytic model was used to estimate costs and outcomes for pregnancies screened using NICE and those screened using the FMF algorithm. The decision point probabilities were calculated using the included cohort. MAIN OUTCOME MEASURES: Incremental healthcare costs and QALY gained per pregnancy screened. RESULTS: Of 5957 pregnancies, 12.8% and 15.9% were screen-positive for development of pre-eclampsia using the NICE and FMF methods, respectively. Of those who were screen-positive by NICE recommendations, aspirin was not prescribed in 25%. Across the three groups, namely, pregnancies without pre-eclampsia, term pre-eclampsia and preterm pre-eclampsia there was a statistically significant trend in rates of emergency caesarean (respectively 21%, 43% and 71.4%; P < 0.001), admission to neonatal intensive care unit (NICU) (5.9%, 9.4%, 41%; P < 0.001) and length of stay in NICU. The FMF algorithm was associated with seven fewer cases of preterm pre-eclampsia, cost saving of £9.06 and QALY gain of 0.00006/pregnancy screened. CONCLUSIONS: Using a conservative approach, application of the FMF algorithm achieved clinical benefit and an economic cost saving.

Impact of a prenatal screening program on the Down syndrome phenotype: An interrupted time series analysis.

INTRODUCTION: We hypothesized that children with Down syndrome who were born after the implementation of first-trimester combined screening for trisomy 13, 18, and 21 and a second-trimester ultrasound scan in Denmark would show a milder syndrome phenotype. We investigated the birth biometry, prevalence of congenital malformations, and early childhood morbidity of children with Down syndrome before and after implementation of this screening program. MATERIAL AND METHODS: A nationwide register-based study of all live born singletons with Down syndrome in Denmark from 1995 to 2018. In interrupted time series analyses, we studied the temporal developments in birth biometry, prevalence of congenital malformations, and early childhood morbidity related to the implementation of a national prenatal screening program. RESULTS: We included 602 singletons with Down syndrome born before and 308 after implementation of the screening program. Z-scores of birthweight and head circumference increased over time before screening, but this temporal development changed after implementation by -0.05 (95% confidence interval [CI]: -0.11 to 0.01) and -0.05 (95% CI -0.12 to 0.02), respectively. Just after implementation, the prevalence of non-severe congenital heart disease decreased (relative change in odds 0.48 [95% CI: 0.24-0.94]). For severe congenital heart disease, atrioventricular septal defect, and non-heart malformations, this change was 1.16 (95% CI: 0.56-2.41), 0.95 (95% CI: 0.43-2.03), and 0.98 (95% CI: 0.33-2.76), respectively. For all malformations, pre-existing temporal developments did not change following implementation of screening. The implementation was associated with higher odds of admission to a neonatal intensive care unit (relative change 1.98 [95% CI: 0.76-5.26]) and an increased risk of hearing impairment (risk difference 3.4% [95% CI: -0.4% to 7.1%]). In contrast, the implementation was not associated with the incidence of hospital admissions by 2 years of age or with the probability of a thyroid disorder. CONCLUSIONS: After implementation of a national prenatal screening program, we did not observe a milder Down syndrome phenotype apart from an apparent reduction in the proportion of children with non-severe congenital heart disease; this result is, however, limited by small numbers.

Comparing prenatal screening experiences of Icelandic women who received false-positive and true-negative first-trimester combined screening results in Iceland in 2012-2016.

First-trimester combined screening (FTS) has been offered to all pregnant women in Iceland since 2003. Individuals with high-risk FTS results are offered an invasive test option with a ≤1% risk of fetal loss. This study gives insight into the prenatal screening and diagnosis experiences and preferences of 101 women who underwent FTS in Iceland in the years 2012-2016, comparing the experience of those who received false-positive FTS results to those who received true-negative results. Retrospective patient-reported anxiety levels at the time of receiving FTS results were significantly higher in those who received false-positive results compared to those who received true-negative results. For a subset of these participants, the anxiety lasted through pregnancy, and for a smaller subset, it lasted even longer. Non-invasive prenatal testing (NIPT) is currently not offered in Iceland, aside from the rare exceptional case. Given the extremely low false-positive rates of NIPT, we believe NIPT is worth considering as Iceland's standard first-tier screening method for trisomy 13, 18, and 21. We believe the findings of this study are beneficial not only for Iceland but also for other countries where FTS is the first-tier prenatal screening method or the only offered test. Additionally, only 21% of participants in our study reported that they had heard of NIPT, which emphasizes the need for comprehensive NIPT pretest information to be available prior to its uptake to ensure informed and autonomous decision-making.

Is there a future for cell-free fetal dna tests in screening for preeclampsia?

CffDNA screening is a powerful diagnostic tool in the prenatal diagnosis algorithm for chromosomal abnormalities. With detailed ultrasound examination as the mainstay of first-trimester risk assessment, cffDNA has been shown to be superior to first-trimester combined screening (FTCS) in false-positive rates for trisomy 21 detection. In light of the growing interest in cffDNA testing and the possibility of it replacing first-trimester biochemistry, we decided to investigate the usefulness of cffDNA tests in early-pregnancy risk assessment for preeclampsia (PE). The aim of this review paper was to evaluate clinical application of first-trimester cfDNA in predicting PE, as well as to investigate its possible use in first-trimester PE screening enhancement, also in cases where biochemistry is not performed.

Information about first-trimester screening and self-reported distress among pregnant women and partners - comparing two methods of information giving in Sweden.

INTRODUCTION: Balanced information before prenatal diagnosis (PND) aims to help expectant parents to make an informed choice. However, it is important that the information does not increase the expectant parents' psychological distress. The aim was to examine psychological distress among expectant parents, before and after receiving information about PND, to evaluate the possible differences between two different procedures of information giving, and to evaluate the association between satisfaction with the information and psychological distress. MATERIAL AND METHODS: A longitudinal design, based on questionnaire data from 380 expectant parents from four counties in Sweden. The measurement points; T1, before the information about PND was given and T2, 2 weeks after the prenatal screening or 15 weeks of gestation. The Hospital Anxiety and Depression Scale (HADS) and the Swedish version of the Cambridge Worrying Scale (CWS) measured psychological distress. The Satisfaction with Genetic Counseling Scale (SCS) measured satisfaction with information about PND. RESULTS: The rate of psychological distress was stable among the pregnant women, but decreased among their partners, after the information was received. General anxiety and the social-medical dimension of pregnancy-related worry decreased among the participants who received information, using the more distinct two-stage process (group A), but was unchanged in group B (less distinct two-stage process). Health-related worry decreased in both groups, whereas relational worry and level of depressive symptoms were unchanged in both groups. CONCLUSION: Information about PND does not increase the psychological distress among expectant parents. A more distinct two-stage process of information giving might even decrease their anxiety.

Enhanced First Trimester Screening for Trisomy 21 with Contingent Cell-Free Fetal DNA: A Comparative Performance and Cost Analysis.

OBJECTIVE: Prenatal screening for trisomy 21 is a standard of care. Emerging cell-free fetal DNA (cffDNA) technologies can improve screening performance, but they are expensive. This study was conducted to propose a contingent screening model that would incorporate cffDNA technology, would remain affordable, and could be applied equitably in a publically funded system. METHODS: Using performance and cost parameters from published literature, four prenatal screening strategies were compared. Scenario 1 modelled integrated prenatal screening (first trimester nuchal translucency and biochemical markers from both the first and second trimesters) with no cffDNA. Scenarios 2 and 3 modelled first trimester combined screening (FTS) and "enhanced FTS" (adding serum placental growth factor and alpha fetoprotein to FTS), respectively, with contingent cffDNA following a positive result. Scenario 4 modelled cffDNA as the primary screening test. RESULTS: Scenario 1 provides a known detection rate (DR) of 88%, with a false positive rate (FPR) of 3.3%. Scenarios 2 and 3 result in a DR of 94% and overall FPR of 0.59% and 0.33%, respectively, comparable to the DR of 96% and FPR of 0.1% with primary cffDNA (assuming the published test failure rate of 3%). The total cost, cost per woman screened, and cost per case of trisomy 21 detected were lower with scenario 3 (enhanced FTS with contingent cffDNA) compared with primary cffDNA or scenario 2 (FTS with contingent cffDNA). CONCLUSION: Enhanced FTS with contingent cffDNA following a positive result provides a similar performance to that of primary cffDNA at a substantially lower cost.

Effectiveness of ovarian age as the background risk for aneuploidy screening in an unselected pregnant population.

The aim of this study was to assess the performance of first-trimester combined screening when replacing the chronological maternal age by Anti-Müllerian hormone (AMH) and antral follicle count (AFC)-derived ovarian ages, as the background risk in trisomy risk estimation. A total of 639 pregnant women who completed first-trimester combined screening together with AMH and AFC determination were included. Trisomy risks were estimated based on three distinct 'maternal ages' as a-priori risk (chronological age, AMH- and AFC-derived ovarian age). The screening performance was assessed using three different approaches: received operator curve; detection rate and false positive rates for a fixed 1/250 threshold; and detection rates for a fixed 3% false positive rate. A non-significant trend was shown for AMH-derived age for both an increased area under the curve (0.986 versus 0.979) and an increased detection rate (from 83% to 100%) for a 1/250 risk threshold. For a 3% false-positive rate, a non-significant trend for increased detection with the use of both AMH- and AFC-derived ovarian ages was observed (from 67% to 83%). These results indicate that, although ovarian derived ages seem to potentially reflect a more precise background risk for fetal trisomies, the improvement in screening performance is only residual.

Correlation Between PAPP-A Levels Determined During the First Trimester and Birth Weight at Full-Term.

Foetal birth weight is an important determinant of perinatal health. For this reason, various methods have been investigated for estimating this weight during pregnancy. The aim of this study is to evaluate the possible relationship between full-term birth weight and pregnancy-associated plasma protein-A (PAPP-A) levels determined during the first trimester as part of combined screening for aneuploidy carried out in pregnant women. We carried out a single-centre study including pregnant women who were being followed up by the Obstetrics Service Care Units of the XXI de Santiago de Compostela e Barbanza Foundation, who gave birth from March 1, 2015, to March 1, 2017, and who had undergone their first-trimester combined chromosomopathy screening. The sample included a total of 2794 women. We found a significant correlation between MoM PAPP-A and foetal birth weight. When MoM PAPP-A was measured at extremely low levels (< 0.3) during the first trimester, the OR for giving birth to a foetus with weight < p10, adjusting for gestational age and sex, was 2.74. For low levels of MoM PAPP-A (0.3-0.44), the OR was 1.52. With regard to the value of MOM PAPP-A levels as a predictor of foetal macrosomia, a correlation could be observed with elevated levels, although this was not statistically significant. PAPP-A determined during the first trimester acts as a predictor of foetal weight at term as well as for foetal growth disorders.

Routine first trimester combined screening for preterm preeclampsia in Australia: A multicenter clinical implementation cohort study.

OBJECTIVE: To assess pregnancy outcomes following first trimester combined screening for preterm preeclampsia in Australia. METHODS: We compared pregnancy outcomes of women with singleton pregnancies who underwent first trimester combined preeclampsia screening with the Fetal Medicine Foundation algorithm between 2014 and 2017 in Melbourne and Sydney, Australia, with those from women who received standard care. The primary outcomes were preterm preeclampsia and screening performance. Effect estimates were presented as risk ratios with 95% confidence intervals. RESULTS: A total of 29 618 women underwent combined screening and 301 566 women received standard care. Women who had combined screening were less likely to have preeclampsia, preterm birth, small neonates, and low Apgar scores than the general population. Women with high-risk results (≥1 in 100) were more likely to develop preterm preeclampsia (2.1% vs. 0.7%, risk ratio [RR] 3.04, 95% CI 2.46-3.77), while low-risk women (risk <1 in 100) had lower rates of preterm preeclampsia (0.2% vs. 0.7%, RR 0.26, 95% CI 0.19-0.35) and other pregnancy complications. Screening detected 65.2% (95% CI 56.4-73.2%) of all preterm preeclampsia cases, with improved performance after adjustment for treatment effect. CONCLUSIONS: First trimester screening for preeclampsia in clinical practice identified a population at high risk of adverse pregnancy outcomes and low-risk women who may be suitable for less intensive antenatal care.

First-Trimester Biochemical Serum Markers in Female Kidney Transplant Recipients-The Impact of Graft Function.

Data on serum biochemistry markers as a component of the first-trimester screening test in pregnant kidney graft recipients are limited. In the absence of a separate validated algorithm, biochemical testing is commonly used in the first-trimester screening in kidney transplant recipients. Therefore, the study aimed to analyze first-trimester serum biochemical markers and the first trimester combined screening results in pregnant kidney graft recipients. A retrospective study was carried out in pregnant women who underwent the first-trimester combined screening test performed per the Fetal Medicine Foundation (FMF) protocol in 2009−2020. The study group included 27 pregnancies in kidney graft transplant recipients, and the control group was 110 patients with normal kidney function, matched according to age, body mass index (BMI), and gestational age. The biochemical serum markers (free beta-human chorionic gonadotropin [beta-hCG] and pregnancy-associated plasma protein A [PAPP-A]) were evaluated using the FMF-approved Roche Elecsys® assay and exhibited as multiples of the median (MoM) values. Data on first-trimester screening test results, perinatal outcomes, and graft function (assessed using serum creatinine concentrations) were analyzed. The analysis of first-trimester screening parameters revealed no difference in nuchal translucency (NT) measurements and uterine artery flow. However, free beta-hCG MoM and PAPP-A values were higher in posttransplant pregnancies than in controls: 3.47 ± 2.08 vs. 1.38 ± 0.85 (p = 0.035) and 1.46 ± 0.81 vs. 0.98 ± 0.57 (p = 0.007), respectively. The false positive rate of trisomy 21 (T21) screening in graft recipients was 25.9% vs. 3% in the controls. The free ß-hCG MoM values positively correlated with serum creatinine levels before (r = 0.653; p < 0.001), during (r = 0.619; p = 0.001), and after pregnancy (r = 0.697; p < 0.001). There was a statistically significant negative correlation for PAPP-A MoM values for postpartum serum creatinine concentration (r = −0.424, p = 0.035). Our results show significantly higher serum concentrations of free beta-hCG and PAPP-A in posttransplant pregnancies than in healthy controls, confirmed when exhibited as MoM values and their association with graft function was assessed by serum creatinine concentration. Taking those changes into account would reduce the high number of false positive test results in this group. The validated first-trimester screening algorithm that considers altered kidney function in pregnant kidney graft recipients remains to be developed.

First trimester combined screening in patients with systemic lupus erythematosus: impact of pre-analytical variables on risk assessment.

BACKGROUND: Prenatal diagnosis of fetal trisomy 21 and other chromosomal abnormalities is based on invasive tests, such as amniocentesis and chorionic villus sampling, which are carried out in women identified through screening as being at high risk for these abnormalities. The most widely used method of screening is the first-trimester combined test which utilizes maternal age, and measurements of fetal nuchal translucency thickness (NT) and maternal serum pregnancy-associated plasma protein-A (PAPP-A) and free ß-human chorionic gonadotropin (hCG). OBJECTIVES: To assess the influence of SLE on the levels of NT, PAPP-A, and ß-hCG and whether any alterations in such levels may increase the rate of false positives and the subsequent number of invasive tests. METHOD: This was a prospective first-trimester screening study for trisomies 21, 18, and 13 by a combination of maternal age, fetal nuchal translucency thickness, and serum PAPP-A and ß-hCG at King's College Hospital, London, between March 2006 and February 2011. The study population included 47 cases with maternal SLE and 45,493 without SLE. The results of biomarkers in the SLE and non-SLE groups were compared. RESULTS: In the SLE group, compared to the non-SLE group, there were no significant differences in median maternal age, fetal NT, or serum PAPP-A MoM, but serum free ß-hCG MoM was increased (1.402, IQR 0.872-2.290 vs 0.994, IQR 0.676-1.508). CONCLUSION: In first trimester screening for trisomies, the measured value of free ß-hCG should be adjusted for maternal SLE to avoid false positive results and overuse of invasive tests.

A contingent model for cell-free DNA testing to detect fetal aneuploidy after first trimester combined screening.

OBJECTIVE: To assess the results of the first trimester combined test to design a prenatal protocol for the introduction of the cell-free fetal DNA test as a contingent screening model. METHOD: An observational retrospective study in 12,327 singleton pregnancies to analyze the results of the combined first trimester screening, the nuchal translucency ≥97.5 percentile, their cytogenetic results and birth outcomes. RESULTS: A total of 533 (4.3%) pregnant women had a risk in combined first trimester screening above 1/300. In this group, sixty nine had an unbalanced karyotype. The abnormal/normal karyotype ratio was 1/28 in pregnant women with intermediate risk (1/51-1/300) for trisomy 21 and trisomy 18, 1/58 with intermediate risk just for trisomy 21 and 1/37 with intermediate risk just for trisomy 18. A 19.8% of the unbalanced karyotypes had chromosomal abnormalities other than trisomies 21, 18 and 13. Two false negatives cases at first trimester combined screening presented a nuchal translucency ≥ p97.5th. CONCLUSION: We propose the introduction of the cell-free fetal DNA test when the risk of first trimester combined screening is intermediate (1/51-1/300) and when nuchal translucency is ≥ p97.5th with a low risk in the combined screening. This policy would allow us to continue to detect uncommon chromosomal abnormalities.

Combined first-trimester Down syndrome screening in HIV-infected women.

OBJECTIVE: To determine if human immunodeficiency virus (HIV) infection or antiretroviral therapy interferes with maternal levels of free human ß-chorionic gonadotrophin (hCGß) and pregnancy-associated plasma protein-A (PAPP-A) and whether any such influence alters first-trimester Down syndrome (DS) screening in HIV-infected women. STUDY DESIGN: We performed a multicenter 1:2 matched case-control study comparing 84 HIV-infected women with singleton pregnancies with controls randomly selected among uninfected women, delivered and screened in the same center and matched for maternal age, geographical origin and fetal sex. RESULTS: Groups did not differ significantly in screening results, although case women showed a slightly lower median free hCGß multiple of the median (MoM) (1.11 versus 1.24 MoM, p=0.32) and higher median PAPP-A MoM (1.45 versus 1.32 MoM, p=0.23) than control women. The false-positive rate was similar in the case and control groups (5% versus 6.5%, p=0.5). Biomarker levels did not differ when comparing treated and untreated patients with their respective controls, and with one another. CONCLUSION: First-trimester DS combined screening biomarker levels and calculated risk do not seem to be significantly altered by HIV infection or antiretroviral treatment. This screening strategy appears to be suitable for HIV-infected women.

First-trimester combined screening is effective for the detection of unbalanced chromosomal translocations at 11 to 12 weeks of gestation.

The first trimester combined screening, which analyzes fetal nuchal translucency and levels of free ß-human chorionic gonadotropin (ß-hCG) and pregnancy-associated plasma protein A (PAPP-A) in maternal serum, is routinely used to detect abnormal pregnancies associated with Down syndrome and other trisomy aneuploidies. Based on the hypothesis that major chromosomal translocations could lead to similar biochemical and developmental outcomes during early embryo development, we compared these markers among pregnancies with normal, balanced, or unbalanced fetal karyotypes. Among the parents, 71 (73%) carry balanced reciprocal translocation and 26 (27%) have Robertsonian translocation. Of the 97 pregnancies tested, 39 (40%), 37 (37%), and 22 (23%) fetuses had normal karyotype, balanced chromosomal translocations, and unbalanced chromosomal translocations, respectively. Importantly, we found that pregnancies with an unbalanced translocation had significantly higher free ß-hCG multiple of the median (MoM) and larger nuchal translucency thickness than those with normal karyotype or balanced translocations. Analysis showed that the area under a receiver operating characteristic curve (AUC) is 0.716, 0.820, and 0.936 for free ß-hCG MoM, PAPP-A MoM, and fetal nuchal translucency, respectively. When these 3 independent factors were combined, the AUC reached 0.976. In addition, logistic regression showed that the most optimal model for predicting an unbalanced chromosomal translocation is a combination of PAPP-A and nuchal translucency with an AUC of 0.980. Therefore, the first trimester combined screening is not only effective in the screening of Down syndrome and other trisomy abnormalities but also has high sensitivity for the detection of unbalanced chromosomal translocations in fetuses.