Knowledge and future preference of Chinese women in a major public hospital in Hong Kong after undergoing non-invasive prenatal testing for positive aneuploidy screening: a questionnaire survey

In the present study, the majority (>90 %) of pregnant women recognised the possibilities of false negative and false positive results of NIPT, while more than 70 % of them recognised its limited sensitivity of detecting uncommon aneuploidies compared with an invasive test, and the possibility of uninformative test results. Only a small proportion (<10 %) of women answered correctly to questions on the applicability of NIPT in special groups of pregnant women. We did not identify any similar studies for comparisons. However, our findings are in accordance with previous studies that pregnant women generally know more about practical aspects of Down syndrome than screening limitations and accuracy [22, 23].

Pregnant women with an advanced level of education had higher proportions of correct answers in two knowledge questions on NIPT than those without. This finding is consistent with previous studies that education level predicted knowledge level on conventional screening for Down syndrome [24‐26]. In addition, pregnant women who underwent NIPT before 15 weeks of gestation had higher proportions of correct answers in two knowledge questions on NIPT than those after 15 weeks. This result is not unexpected, as first-trimester screening is associated with the use of NIPT [13, 27]. We postulate that women with an earlier NIPT are more willing to know more about the test. Although Nullipara and employed women are associated with the use of NIPT, our present study did not show that these subgroups of women knew more about NIPT than Multipara and the unemployed. It seems that the need for adequate pre-test counselling of women is not limited to particular subgroups [28].

More women preferred conventional screening before NIPT to direct NIPT (57.8 % vs 30.4 %) even though they had experience with the forme. Women were most concerned with the cost of a screening test [29] besides the risk of miscarriage [30]. We postulate that the difference in their preferences was related to the price difference between a ‘free’ conventional screening offered by a public hospital and an expensive self-financed NIPT. However, if the price of NIPT decreases to an acceptable level in the future, women’s preference will probably change to opting for NIPT as a primary screening.

Consistent with a previous study [28], the women’s preference or self-risk assessment was independent of maternal age, education or parity. Less than half of the women replied that their information on NIPT was received from their private doctors, while nearly half of women learned it from the web. Self-risk assessment was influenced largely by counselling by health-care professionals and the media apart from personal experience [28].

The web is a common way of searching for information nowadays, but the accuracy of information on the web is variable. No specific healthcare profession most suited to providing counselling on NIPT has been identified. ACMG and NSGC recommend counselling by a qualified prenatal care provider, a trained designee or a genetic counsellor [20, 21]. In a study in U.K., women preferred pre- and post-NIPT counselling by a midwife [14]. In Hong Kong, trained midwives in maternal and fetal medicine team have been providing prenatal counselling on universal conventional Down syndrome screening to all pregnant women. This provides a good platform for further training on NIPT counselling. Continuous education is required to equip obstetricians and midwives with the competences in providing such counselling [31]. In a previous study on conventional screening tests, obstetricians would prefer waiting longer and accepting a greater decrease in detection rate for a safer test than midwives [32]. However, another study showed no correlation between individual healthcare professionals’ attitudes and screening uptake [33]. The determinants of the uptake rate of a diagnostic test are patient-centred after adequate counselling is provided [34].

NIPT should be offered in the context of informed decision making, education, pre-test and post-test, and counselling [18‐21, 35]. In a previous study, around 72 % of women declined NIPT [35]. In the present study, around half the women preferred conventional screening despite a previous history of NIPT. High-risk women electing NIPT tend to have higher scores of depression/anxiety [36]. An increased level of knowledge of prenatal screening for Down syndrome was associated with less ambivalence and higher level of wellbeing, but not with worries about the results [37]. The information given should include the purpose, advantages, follow-up invasive testing, and limitations of NIPT [20]. Despite a risk of about 5 % of an uninformative test result of NIPT [35], about 30 % of the women in the present study were not aware of this possibility. Uninformative test results could lead to a delay in diagnosis or unavailability of information for risk assessment [20]. Besides, about 30 % of women were not aware of the limitation of NIPT in the detection of uncommon aneuploidies compared to an invasive test. It is important to correct false assumptions that might otherwise lead to these tests being declined by patients [25].

A major strength of this study was that the ten knowledge questions in the questionnaire were designed according to the ISPD rapid response statement [18]. It seems that this is the first time such a questionnaire was used to assess women’s knowledge on NIPT as far as we know. Whether a shorter questionnaire consisting of knowledge questions 1 to 5 is sufficient to test women’s basic knowledge on NIPT requires further study, as knowledge questions 6 to 10 appeared too complicated or difficult for the women to answer. Limitations of this pilot study are the small sample size, single centre and exclusively Chinese population. Significant bias might have been introduced by offering assistance by an experienced midwife to the women during completion of the questionnaire. However, the assistance was provided in a straightforward manner and confined to explanation of medical terms or general terms if Cantonese was not their mother tongue. Moreover, we did not assess women’s knowledge on other limitations of NIPT involving turn-around time, screening for open neural tube defects, anomaly, and late-pregnancy complications as stated in the ACMG policy statement [20]. Furthermore, we also did not assess other aspects like determination of fetal sex, maternal DNA abnormalities [38] and paternity testing [39]. In this pilot study, question 4 in Table 2 was not well constructed because it consisted of two sentences, although we intended to pose the last part; that is, for some women the extended period awaiting confirmatory invasive testing results is likely to be highly stressful. The lack of validity checking by experts, assessment of applicability and reliability of the questionnaire are limitations of this pilot study. We will further develop the questionnaire in our subsequent studies.