Cost-effectiveness analysis of triple test in second-trimester maternal serum screening for Down's syndrome: an experience from Taiwan with decreasing birth rate but increasing population of old pregnant women

Effect of maternal polycystic ovary syndrome (PCOS) on screening of aneuploidy in the first and second trimesters

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterized by insulin resistance and hormonal disorder in women. This study aimed to assess the effect of maternal PCOS on screening of aneuploidy in the first and second-trimesters.

METHODS

This case-control study was conducted in Arash Hospital and Nilou Laboratory in 2017-2018. The screening test was conducted on 90 PCOS and 90 healthy mothers. Finally, the first and second-trimester screening was compared between the two groups using Chi-square, Mann-Whitney's U and students T tests and regression model by SPSS 21. P < 0.05 was considered as statistically significant.

RESULTS

Free Beta-Human Chorionic Gonadotropin (Free-β-HCG) (P = 0.04), inhibin-A (P = 0.001) and Alpha Fetoprotein (AFP) (P = 0.02) levels were higher in the PCOS women comparing to the healthy women but there was no significant difference between the mean of HCG, Plasma Protein A (PAPP-A), and Unconjugated Estriol (UE3) between the two groups. Pre-eclampsia (P < 0.001) and trisomy 18 risks in quad screening were higher in the PCOS women (P = 0.002) than the control group; however, trisomy 13, trisomy 18 and trisomy 21 risks, Smith-Lemli-Opitz Syndrome (SLOS) and Neural Tube Defect (NTD) risks were not different between the two groups. The logistic regression model showed that the first- and second-trimester screening of aneuploidywas related to PCOS.

CONCLUSIONS

There was a significant difference in the mean of free-β-HCG, inhibin-A, AFP level, and the risks of pre-eclampsia, SLOS and trisomy 18 between the two groups but no significant association was found in the mean of HCG, PAPP-A, UE3, NTD and other aneuploidies between the two groups. PCOS may affect the first- and second-trimester screening tests and pregnancy health. It may also require correction in the calculation of risks related to the first- and second-trimester screening for aneuploidy.

The relationship between environmental exposures and hormonal abnormalities in pregnant women: An epidemiological study in Yazd, Iran

PROBLEM

The process of industrialization and lifestyle changes have gradually exposed human ‎societies to a larger number of environmental risk factors, which may cause hormonal ‎abnormalities and congenital anomalies.

BACKGROUND

The current study aimed to investigate the relationship ‎between environmental factors and hormonal abnormalities among pregnant women in Yazd, ‎Iran.

METHODS

A hundred participants were randomly selected from among a group of pregnant women. According to the screening tests (AFP, free β-‎HCG, uE3, PAPP-A, and inhibin-A) performed at the genome clinic in Yazd in 2016, the risk of Down Syndrome (DS) was sufficiently high in this group of pregnant women from which the participants were selected. A ‎questionnaire was used to collect data on the degree of the participants' exposure to pesticides ‎at home, use of canned and fast foods, and consumption of greenhouse fruits. The collected data were ‎analyzed by One-way ANOVA and Kruskal-Wallis Test.

FINDINGS

The mean of Multiple of Median (MoM) for inhibin-A was significantly higher among pregnant ‎women who often or always used pesticides at home (p=0.047). The mean MoM ‎for free β-HCG was significantly higher among pregnant women who often or always used canned ‎foods (p=0.024). Finally, the mean MoM for uE3 (1.85±1.30) was significantly higher among ‎pregnant women who never consumed greenhouse fruits (p=0.003).

CONCLUSION

It can be concluded that it is possible to reduce environmental exposures affecting hormonal abnormalities among pregnant women by improving nutritional patterns, minimizing the use of pesticides at home, and reducing the intake of canned foods and greenhouse fruits.

Prospective study of the feasibility and effectiveness of a second-trimester quadruple test for Down syndrome in Thailand

OBJECTIVE

To evaluate the feasibility and effectiveness of a quadruple test for Down syndrome in the second trimester of pregnancy in clinical settings in Thailand.

METHODS

From October 2015 to September 2016, a prospective study was undertaken in 19 hospitals in Songkhla province, Thailand. Women with a singleton pregnancy of 14-18 weeks were enrolled and underwent the quadruple test. The risk cutoff value was set at 1:250. All women with a positive test (risk ≥1:250) were offered amniocentesis. Women were followed up until delivery.

RESULTS

Among 2375 women, 206 (8.7%) had a positive quadruple test; 98 (47.6%) of these women voluntarily underwent amniocentesis. Overall, seven pregnancies were complicated with chromosomal abnormalities (2.9 cases in 1000), including four cases of Down syndrome (1.7 in 1000) and three of other abnormalities. The detection, false-positive, and accuracy rates of the quadruple test for Down syndrome were 75.0%, 8.6%, and 91.4%, respectively.

CONCLUSION

The quadruple test was found to be a feasible and efficient method for screening for Down syndrome in the second trimester of pregnancy in a Thai clinical setting. The test should be performed for pregnant women before an invasive test for Down syndrome.

Prenatal cytogenetic diagnosis in Taiwan: a nationwide population-based study

PURPOSE

The goal of this study was to gain a better understanding of the status of advanced maternal age among criteria for provision of amniocentesis in pregnant women in Taiwan.

MATERIALS AND METHOD

Data of 315 670 second-trimester amniocenteses from 28 national certified cytogenetics laboratories were retrospectively analyzed from the Prenatal Genetic Diagnosis Declaring and Database System of the Health Promotion Administration, Ministry of Health and Welfare in Taiwan between 2006 and 2013.

RESULTS

The number of pregnant women undergoing amniocentesis in Taiwan between 2006 and 2013 increased, and the most common three indications for amniocentesis were advance maternal age (75.11%), abnormal second trimester maternal serum screening (13.22%) and abnormal sonographic finding (8.00%). Down syndrome was the most common autosomal abnormality identified (25.74%); Turner syndrome was the most common sex chromosome abnormality (7.04%). Of structural rearrangements, 26.93% were balanced translocations and 17.10% were unbalanced translocations. The greatest proportion of fetal chromosomal abnormalities was found in cases where parents were also affected (38.02%).

CONCLUSIONS

Clinical workers should provide detailed genetic diagnostic information to pregnant women, especially those with the common amniocentesis indications, which will enable them to determine a birth plan.

Integrated care for Down syndrome

Down syndrome (DS), caused by an extra copy of chromosome 21 (trisomy 21), is the most intensively studied human aneuploidy condition. It is the leading cause of intellectual disability and birth defects. Although most prenatally diagnosed DS fetuses are aborted in Taiwan, there are still some infants with DS who are diagnosed after birth. In addition to intellectual disability, people with DS face systemic problems that include short stature, dysmorphism, congenital heart disease, congenital anomalies of gastrointestinal and genitourinary tracts, abnormal endocrine function, leukemia and leukemoid reactions. To provide better care for people with DS in Taiwan, we began the DS multi-disciplinary clinic that has opened once per month since November 2013. The multi-disciplinary clinic consists of several subspecialists who provide care for DS people. To date, approximately 200 patients have used the clinic. The average number of patients who use the clinic per month is 27±6 with a mean patient age of 16±12 years old (range 0.3-53 years). The average number of patients per specialist on each clinic day is 5.2±4.9 (range 0.5-20.9 patients). We focus on early detection and prevention of medical and developmental issues associated with DS. This coordinated approach allows DS patients and family to have more comprehensive care.

Two kinds of common prenatal screening tests for Down's syndrome: a systematic review and meta-analysis

As the chromosomal examination of foetal cells for the prenatal diagnosis of Down's syndrome (DS) carries a risk of inducing miscarriage, serum screening tests are commonly used before invasive procedures. In this study, a total of 374 records from PubMed, EMBASE, and the ISI Science Citation Index databases were reviewed. As a result of duplication, insufficient data, and inappropriate article types, 18 independent articles containing 183,998 samples were used in the final systematic review and meta-analysis of the diagnostic performance of the serum triple screening test (STS) and the integrated screening test (INS). Data extracted from the selected studies were statistically analysed, and the presence of heterogeneity and publication bias was assessed using specific software. The overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the area under the curve for the STS were 0.77 (95% confidence interval = 0.73-0.81), 0.94 (0.94-0.94), 9.78 (6.87-13.93), 0.26 (0.22-0.31), 44.72 (30.77-65.01), and 0.9064, respectively. For the INS, these values were 0.93 (0.90-0.95), 0.93 (0.93-0.93), 22.38 (12.47-40.14), 0.08 (0.05-0.11), 289.81 (169.08-496.76), and 0.9781, respectively. These results indicate that the INS exhibits better diagnostic value for DS. However, further research is needed to identify other biomarkers to improve prenatal screening tests.

The impact of Down syndrome screening on Taiwanese Down syndrome births: a nationwide retrospective study and a screening result from a single medical centre

A retrospective analysis of the Taiwanese National Birth Defect Registration and Notification System was conducted in order to determine the live birth- and stillbirth rates in infants with Down syndrome, trisomy 18, trisomy 13 and Turner syndrome between 2001 and 2010. The objective was to investigate the impact of Down syndrome screening on the Taiwanese Down syndrome live birth rate. In addition, the results of first-trimester Down syndrome screening between 2006 and 2011, and of second-trimester quadruple testing between 2008 and 2011, were obtained from the National Taiwan University Hospital. All Taiwanese infants born between 2001 and 2010 were included in the first part of the analysis, and women receiving first-trimester Down syndrome screening or second-trimester quadruple testing from the National Taiwan University Hospital were included in the second part. The live birth rate of infants with Down syndrome, per 100 000 live births, decreased from 22.28 in 2001 to 7.79 in 2010. The ratio of liveborn DS to total DS was 48.74% in 2001, and then decreased to 25.88% in 2006, when first-trimester screening was widely introduced in Taiwan. This ratio dropped to 20.64% in 2008, when the second-trimester quadruple test was implemented. The overall positive rate in first-trimester screening in the National Taiwan University Hospital was 3.1%, with a Down syndrome detection rate of 100%; the quadruple test had values of 9.0% and 75%, respectively. The use of first-trimester screening and the second-trimester quadruple test may be responsible for the marked decrease in the Taiwanese Down syndrome live birth rate observed between 2001 and 2010.

Informed consent for antenatal serum screening for Down syndrome

OBJECTIVE

Respect for patients' autonomy is a principle issue in medical ethics. Patients' understanding of antenatal serum screening for Down syndrome upon informed consent has barely been assessed. Our objective was to evaluate pregnant women's perceived level of understanding of this serum screening.

MATERIALS AND METHODS

Pregnant women between the 15(th) and 21(st) gestational week were randomized into control and experimental groups, and were asked to complete a questionnaire before and after genetic counselling provided by researchers. The primary endpoints were the perceived level of understanding of serum screening for Down syndrome and the autonomy of the decision making for this serum screening. The secondary endpoints were the anxiety and depression levels of these women.

RESULTS

Participants in the experimental group (n = 96) had a significantly higher perceived level of understanding of antenatal serum screening for Down syndrome than participants in the control group (n = 97). There were significantly more respondents in the experimental group making the decision themselves to undergo serum screening than women in the control group. Anxiety and depression levels were not significantly different between the women in the two groups.

CONCLUSION

Pregnant women should be offered more information to allow them to make an informed decision before they undergo antenatal serum screening for Down syndrome. Comprehensive genetic counseling improved pregnant women's autonomy in deciding whether to participate in serum screening. Health service providers should make effort to fulfill the ethical requirements of informed consent.

Second-trimester maternal serum quadruple test for Down syndrome screening: a Taiwanese population-based study

OBJECTIVE

To assess the usefulness of quadruple test screening for Down syndrome in Taiwan.

MATERIALS AND METHODS

Maternal serum concentrations of alpha-fetoprotein, human chorionic gonadotropin, unconjugated estriol, and inhibin A were measured in 21,481 pregnant women from 15 to 20 weeks of gestation.

RESULTS

Of the 21,481 women, 977 returned values greater than the high-risk cut-off value (1 in 270). Most of these women (86.2%) decided to have an invasive procedure for genetic diagnosis. Nine cases of Down syndrome and 19 cases of other chromosomal anomalies were detected prenatally. Two children with Down syndrome were diagnosed after delivery even though a low estimated risk was determined following the quadruple test. The detection rate was 81.8% (nine out of 11 cases), with a 4.4% false-positive rate. The median multiple of the median value for a-fetoprotein, human chorionic gonadotropin, unconjugated estriol and inhibin A were 0.87, 2.34, 0.77 and 2.16, respectively, in affected cases.

CONCLUSION

This is the first study of the quadruple test for Down syndrome in a Chinese population. Our findings suggested that the second-trimester quadruple test provides an effective screening tool for Down syndrome in Taiwan.

First-trimester Down syndrome screening in women younger than 35 years old and cost-effectiveness analysis in Taiwan population

OBJECTIVES

Outcome of the first-trimester Down syndrome screening in younger population was less reported before. We present the outcome of this screening in Taiwanese women younger than 35 years old. We also test whether or not the first-trimester Down syndrome screening of women <35 years of age and women >35 years old routinely receiving amniocentesis is cost-effective compared with all pregnant women screened with this test in the setting of increased maternal age.

METHODS

From 1999 to 2007, the first-trimester Down syndrome screening including nuchal thickness, pregnancy-associated plasma protein A and free beta-hCG are provided to 10 811 singleton women <35 years of age with the cut-off of 1/270. A cost-effectiveness analysis of young women receiving this screening and older women undergo amniocentesis versus all women undergo this screening was performed in Taiwan population from 1987 to 2006, in which advanced age pregnancies increased from 2.8% to 11.6% of total pregnancies.

RESULTS

Detection rates of trisomy 21, trisomy 18, Turner syndrome and other chromosome anormalies in women <35 years of age are 87.5% (14/16), 50% (2/4), 80% (8/10) and 63% (12/19), respectively, with a false-positive rate of 5.5% (590/10 811). As advanced age pregnancies reached 11.6%, the average cost per one case averted for all women screened ranged from $77 204 to $98 421, while the cost ranged from $99 647 to $116 433 for only women <35 years of age receiving this screening.

CONCLUSIONS

In an aging population, the first-trimester Down syndrome screening should be implemented for all pregnant women when it is available.