Factors determining uptake of invasive testing following first-trimester combined testing

Older mothers and increased impact of prenatal screening: stable livebirth prevalence of trisomy 21 in the Netherlands for the period 2000-2013

In the Netherlands, there is no registry system regarding the livebirth prevalence of trisomy 21 (T21). In 2007, a national screening programme was introduced for all pregnant women, which may have changed the livebirth prevalence of T21. The aim of this study is to analyse trends in factors that influence livebirth prevalence of T21 and to estimate the livebirth prevalence of T21 for the period of 2000–2013. National data sets were used on the following: (1) livebirths according to maternal age and (2) prenatal testing and termination of pregnancy (ToP) following diagnosis of T21. These data are combined in a model that uses maternal age-specific risk on T21 and correction factors for natural foetal loss to assess livebirth prevalence of T21. The proportion of mothers aged ≥ 36 years has increased from 12.2% in 2000 to 16.6% in 2009, to gradually decrease afterwards to 15.2% in 2013. The number of invasive tests performed adjusted for total livebirths decreased (5.9% in 2000 vs. 3.2% in 2013) with 0.18% a year (95% CI: −0.21 to −0.15; p   < 0.001). Following invasive testing, a higher proportion of foetuses was diagnosed with T21 (1.6% in 2000 vs. 4.8% in 2013) with a significant increase of 0.22% a year (95% CI: 0.18–0.26; p < 0.001). The proportion of ToP subsequent to T21 diagnosis was on average 85.7%, with no clear time trend. This resulted in a stable T21 livebirth prevalence of 13.6 per 10,000 livebirths (regression coefficient −0.025 (95% CI: −0.126 to 0.77; p = 0.60).

Trial by Dutch laboratories for evaluation of non-invasive prenatal testing. Part I-clinical impact

Objective

To evaluate the clinical impact of nationwide implementation of genome‐wide non‐invasive prenatal testing (NIPT) in pregnancies at increased risk for fetal trisomies 21, 18 and 13 (TRIDENT study).

Method

Women with elevated risk based on first trimester combined testing (FCT ≥ 1:200) or medical history, not advanced maternal age alone, were offered NIPT as contingent screening test, performed by Dutch University Medical laboratories. We analyzed uptake, test performance, redraw/failure rate, turn‐around time and pregnancy outcome.

Results

Between 1 April and 1 September 2014, 1413/23 232 (6%) women received a high‐risk FCT result. Of these, 1211 (85.7%) chose NIPT. One hundred seventy‐nine women had NIPT based on medical history. In total, 1386/1390 (99.7%) women received a result, 6 (0.4%) after redraw. Mean turn‐around time was 14 days. Follow‐up was available in 1376 (99.0%) pregnancies. NIPT correctly predicted 37/38 (97.4%) trisomies 21, 18 or 13 (29/30, 4/4 and 4/4 respectively); 5/1376 (0.4%) cases proved to be false positives: trisomies 21 (n = 2), 18 (n = 1) and 13 (n = 2). Estimated reduction in invasive testing was 62%.

Conclusion

Introduction of NIPT in the Dutch National healthcare‐funded Prenatal Screening Program resulted in high uptake and a vast reduction of invasive testing. Our study supports offering NIPT to pregnant women at increased risk for fetal trisomy. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

What's already known about this topic?

Non‐invasive prenatal testing (NIPT) for trisomies 21, 18 and 13 is mainly offered in a commercial setting.

Offering NIPT to pregnant women at increased risk for fetal trisomy leads to a reduction in invasive testing.

What does this study adds?

NIPT implemented as a contingent test under the umbrella of a national health authority‐supported fetal trisomy screening program facilitates optimal counseling with close to 100% follow‐up, results in 86% uptake and confirms a major reduction of invasive tests.

Reasons for accepting or declining Down syndrome screening in Dutch prospective mothers within the context of national policy and healthcare system characteristics: a qualitative study

BACKGROUND

Uptake rates for Down syndrome screening in the Netherlands are low compared to other European countries. To investigate the low uptake, we explored women's reasons for participation and possible influences of national healthcare system characteristics. Dutch prenatal care is characterised by an approach aimed at a low degree of medicalisation, with pregnant women initially considered to be at low risk. Prenatal screening for Down syndrome is offered to all women, with a 'right not to know' for women who do not want to be informed on this screening. At the time this study was performed, the test was not reimbursed for women aged 35 and younger.

METHODS

We conducted a qualitative study to explore reasons for participation and possible influences of healthcare system characteristics. Data were collected via ten semi-structured focus groups with women declining or accepting the offer of Down syndrome screening (n = 46). All focus groups were audio- and videotaped, transcribed verbatim, coded and content analysed.

RESULTS

Women declining Down syndrome screening did not consider Down syndrome a condition severe enough to justify termination of pregnancy. Young women declining felt supported in their decision by perceived confirmation of their obstetric caregiver and reassured by system characteristics (costs and age restriction). Women accepting Down syndrome screening mainly wanted to be reassured or be prepared to care for a child with Down syndrome. By weighing up the pros and cons of testing, obstetric caregivers supported young women who accepted in the decision-making process. This was helpful, although some felt the need to defend their decision to accept the test offer due to their young age. For some young women accepting testing, costs were considered a disincentive to participate.

CONCLUSIONS

Presentation of prenatal screening affects how the offer is attended to, perceived and utilised. By offering screening with age restriction and additional costs, declining is considered the preferred choice, which might account for low Dutch uptake rates. Autonomous and informed decision-making in Down syndrome screening should be based on the personal interest in knowing the individual risk of having a child with Down syndrome and system characteristics should not influence participation.

UK NHS pilot study on cell-free DNA testing in screening for fetal trisomies: factors affecting uptake

OBJECTIVE

This study reports on the clinical implementation of cell-free DNA (cfDNA) testing, contingent on the results of the combined test, in screening for fetal trisomies 21, 18 and 13 in two UK National Health Service hospitals. Women with a combined-test risk of ≥ 1:100 (high risk) were offered the options of chorionic villus sampling (CVS), cfDNA testing or no further testing and those with a risk of 1:101 to 1:2500 (intermediate risk) were offered cfDNA or no further testing. The objective of the study was to examine the factors affecting patient decisions concerning their options.

METHODS

Combined screening was performed in 6651 singleton pregnancies in which the risk for trisomies was high in 260 (3.9%), intermediate in 2017 (30.3%) and low in 4374 (65.8%). Logistic regression analysis was used to determine which factors among maternal characteristics, fetal nuchal translucency thickness (NT) and risk for trisomies were significant predictors of opting for CVS in the high-risk group and opting for cfDNA testing in the intermediate-risk group.

RESULTS

In the high-risk group, 104 (40.0%) women opted for CVS; predictors for CVS were increasing fetal NT and increasing risk for trisomies, while the predictor against CVS was being of Afro-Caribbean racial origin (r = 0.366). In the intermediate-risk group, 1850 (91.7%) women opted for cfDNA testing; predictors for cfDNA testing were increasing maternal age, increasing risk for trisomies and university education, while predictors against cfDNA testing were being of Afro-Caribbean racial origin, smoking and being parous (r = 0.105).

CONCLUSIONS

This study has identified factors that can influence the decision of women undergoing combined screening in favor of or against CVS and in favor of or against cfDNA testing.