Preference assessment of prenatal diagnosis for Down syndrome: is 35 years a rational cutoff?

OBJECTIVE: To compare the perceptions of miscarriage and birth of a child with Down syndrome among pregnant women and to evaluate the implications of these preferences for the traditional 35-year old maternal age risk boundary. METHODS: An interviewer-administered survey was given to 186 pregnant women receiving antepartum care at a university hospital. Preferences, as reflected by utilities, for birth of a child with Down syndrome and pregnancy miscarriage, stratified by patient characteristics, were assessed. RESULTS: The utility for the birth of a child with Down syndrome decreased (p < 0.001) as clinical severity increased from mild (0.78) to severe (0.65). Miscarriage of a pregnancy had a mean utility of 0.76 +/- 0.31. Women who desired prenatal diagnosis had a utility value for miscarriage (0.79 +/- 0.28) that was significantly higher than for the birth of a child with Down syndrome of unknown severity (0.73 +/- 0.27). In multivariable logistic regression, desire for prenatal diagnosis was the only factor associated with a preference of miscarriage over birth of an affected child (odds ratio 2.26, 95% confidence interval 1.03, 4.96). CONCLUSION: Women who desire prenatal diagnosis do not perceive the birth of a child with Down syndrome and a pregnancy miscarriage to be equivalent health states. This finding calls into question the rationale of the 35-year-old maternal age criterion and suggests that actual patient preferences should be better incorporated into the decision to offer definitive prenatal diagnosis.     

妊娠中期二联唐氏综合征筛查法在浙南地区32188例孕妇中的筛查效率

目的 采用二联法(母血清甲胎蛋白和β-人绒毛膜促性腺激素)对浙南地区妊娠中期孕妇进行唐氏综合征筛查,评估其筛查效率. 方法 对本地区孕妇根据知情同意原则在妊娠中期取羊水进行常规二联唐氏综合征筛查,筛查出的高风险(≥1∶270)孕妇采用羊膜腔穿刺、羊水细胞培养和染色体核型分析进行产前诊断.通过本地区的三级妇幼保健网对本地区行产前唐氏综合征筛查或未行筛查的孕母分娩的新生儿进行临床随访,对可疑唐氏综合征的新生儿行外周血染色体核型分析进行诊断.正态分布计量资料采用均数±标准差(x-±s)表示,组间差异比较采用两独立样本t检验；计数资料用率表示,组间差异比较采用x2检验.唐氏综合征的危险概率用随机筛查软件进行统计分析. 结果 2007年10月至2010年5月,本地区共32 188例单胎妊娠孕妇接受筛查,唐氏综合征高风险者为1130例,低风险31 058例.高风险者中90.79％(1026/1130)接受产前诊断,确诊7例唐氏综合征胎儿均引产终止妊娠；另外104例未接受产前诊断的孕妇分娩1例唐氏综合征患儿.31 058例低风险者中新生儿出生后确诊唐氏综合征6例,发生率0.19‰.接受产前筛查者中唐氏综合征患病率为0.43‰(14/32 188).妊娠中期二联唐氏综合征筛查检出率为57.14％(8/14),假阳性率为3.48％(1122/32 188),阳性预测值为7.08‰(8/1130).同期,由于各种原因未接受唐氏综合征产前筛查的孕妇达到23 813例,分娩唐氏综合征患儿15例,患病率0.63‰.与接受筛查者中的患病率(0.43‰)差异无统计学意义(x2=1.004,P＞0.05).本地区唐氏综合征总体患病率为0.52‰(29/56 001). 结论 产前筛查和诊断可以减少唐氏综合征患儿出生.但本研究中妊娠中期二联唐氏综合征筛查法的检出率、假阳性率和阳性预测值均较低,可能与本研究所采用的正常值范围并不适用于中国人群有关.     

Down syndrome risk estimation after normal genetic sonography

OBJECTIVE: The objective of this study was to determine whether there are any indication-specific variations in risk reduction for fetal Down syndrome after a normal genetic sonogram. STUDY DESIGN: A second-trimester genetic sonogram was offered to all pregnant women who were at increased risk for fetal Down syndrome (>/=1:274) because of either advanced maternal age (>/=35 years), an abnormal triple screen, or both. Outcome information included the results of genetic amniocentesis (if performed), the results of pediatric assessment, and follow-up after birth. Normal genetic sonography was defined as the absence of all ultrasound aneuploidy markers. RESULTS: The overall prevalence of fetal Down syndrome in the tested population was 1.41% (53/3,753 pregnancies); however, in the presence of normal genetic sonography, the overall prevalence of fetal Down syndrome was 0.21% (7/3,291 pregnancies). The overall risk reduction for fetal Down syndrome in the presence of normal genetic sonography was 6.64-fold (95% CI, 3.01-14.62); the overall negative likelihood ratio was 0.15 (95% CI, 0.07-0.33). In the presence of normal genetic sonography, the risk for fetal Down syndrome was reduced by 83% in patients with advanced maternal age, 88% in patients with abnormal triple screen, 89% in patients with abnormal triple screen who were <35 years old, and 84% in patients who had both abnormal triple screen and advanced maternal age. CONCLUSION: There were no significant variations in the risk reduction for fetal Down syndrome in the presence of normal genetic sonography. Regardless of the indication for testing, the likelihood for fetal Down syndrome was reduced by 83% to 89%. This information will be useful in counseling pregnant women who are at high risk for fetal Down syndrome and who prefer to undergo genetic sonography before deciding about genetic amniocentesis.     

Re-evaluation of risk for Down syndrome by means of the combined test in pregnant women of 35 years or more

OBJECTIVE: Evaluation of combined test in pregnant women 35 years of age and over to detect fetal Down syndrome. MATERIALS AND METHODS: The study population included 408 pregnant women of 35 years and over, who requested the combined test (nuchal translucency, PAPP-A, free beta hCG, maternal age, cut-off 1:250) before deciding whether to undergo amniocentesis. RESULTS: The test was positive in 66 women who then requested amniocentesis for fetal karyotype determination; the other women had a negative test and declined amniocentesis. False-positives increased with maternal age from 6.6% at 35 years to about 50% at 40 to 41 and 100% in women over 41. Six cases of Down syndrome and two cases of trisomy 18 were detected. Not a single case of Down syndrome or trisomy 18 was missed, and other chromosome abnormalities were detected as well. CONCLUSIONS: The application of the combined test reduced the need for invasive testing to only 14% of the studied pregnant population, without missing any of the fetuses with trisomy 21 or 18.     

Levels of knowledge of Down syndrome and Down syndrome testing in Australian women

At their first hospital antenatal visit, 209 women were interviewed to explore their level of knowledge of Down syndrome and the available prenatal tests. Overall, the women had limited knowledge. Non-Caucasian women had less knowledge of Down syndrome, available prenatal tests and the association of Down syndrome with advanced maternal age than Caucasian women. Women with a history of a previous pregnancy and women over 35 years of age were not more aware of Down syndrome or the available tests than other women. These findings have significant implications for antenatal education and the implementation of screening programs for Down syndrome.     

产前行妊娠相关血浆蛋白A筛查联合FISH诊断Down综合征

目的 :应用单项妊娠相关血浆蛋白A(PAPP A)筛查与羊水间期荧光原位杂交 (FISH)产前诊断相结合预防妊娠Down综合征胎儿。方法 :采用酶联免疫方法 (ELISA)对孕周分别为 6～ 2 7周的 1839例孕妇进行母血PAPP A单项筛查 ,以低于同一孕周的中位数时视为可能妊娠Down综合征胎儿的高风险孕妇。取高风险孕妇羊水细胞直接进行间期FISH产前诊断并同时用部分羊水细胞遗传学检查作对照。结果 :检出 1例孕 7周孕妇其PAPP A值为 0 0 5 1U/L ,低于同一孕周中位数 2 0多倍。羊水细胞间期FISH结果显示 ,含 5个杂交信号的核占所有杂交核的 38 5 % ,与细胞遗传学分析的 2 1三体核型完全一致。结论 :单项PAPP A筛查与羊水间期细胞FISH相结合是早期防治妊娠Down综合征有效可行的方法。     

Pregnancy and Neonatal Outcomes of Women With Reactive Syphilis Serology in Alberta, 2002 to 2006

ObjectivesTo describe the maternal characteristics, diagnosis, and pregnancy, and the neonatal outcomes of pregnant women with reactive syphilis serology in a Canadian cohort. Methods: We conducted a retrospective chart review of pregnant women in Alberta with reactive syphilis serology between 2002 and 2006. Clinical staging of syphilis in mothers and infants was determined using provincial and national surveillance criteria.ResultsSeventy-five pregnancies met the inclusion criteria. Thirty women were adequately treated pre-conception, 20 women had infectious syphilis (10 primary, 5 secondary, 5 early latent), 24 had late latent syphilis, and one had disease of unknown stage. Seven infants with congenital syphilis and one infant with presumed congenital syphilis were born to women with primary (n = 4), secondary (n = 2), early latent (n = 1), and unknown stage (n = 1) syphilis. Treatment was provided prior to delivery in one woman; five women did not access prenatal care. Four infants had long-term sequelae.ConclusionAll infants with congenital syphilis were born to women with infectious syphilis who had limited prenatal care. Initiatives to reach women at high risk are required to decrease the incidence of congenital syphilis.     

The relationship between utilization of prenatal care and Down syndrome live births.

OBJECTIVE: This study evaluated whether utilization of prenatal care, as measured by the Kessner index, affects the number of Down syndrome live births. METHODS: A retrospective analysis of birth certificate data of Down syndrome live births comparing 1989 to 2001 by year, maternal age, gestational age at first prenatal visit, and adequacy of prenatal care according to Kessner categories of adequacy of prenatal care. RESULTS: Down syndrome live births were inversely correlated with adequacy of prenatal care. Reductions in Down syndrome live births were seen in all categories of prenatal care in all age groups. In 2001 a minimum 30% reduction was seen in any category rising to a 58% reduction in women > or =35 years with adequate prenatal care. The largest reductions were seen in women > or =35 years of age. CONCLUSIONS: Reductions in Down syndrome live births occurred in all age groups between 1989 and 2001. Utilization of prenatal care as measured by the Kessner index was associated with reductions in Down syndrome live births, with a greater reduction in women > or =35 years of age.     

Older maternal age and infant mortality in the United States

We used data from the National Infant Mortality Surveillance project to examine the effect of older maternal age on infant mortality for the 1980 United States birth cohort. The 1,579,854 births and 14,591 deaths of singletons who were black or white and whose mothers were 25-49 years of age were included. Direct standardization was used to calculate birth-weight-adjusted relative risks of neonatal and postneonatal mortality, using the birth weights of infants with maternal age 25-29 as the standard. We found that the risk of infant mortality was nearly equal for infants born to mothers 25-29 and 30-34 years of age; infants born to mothers 35-39 years of age were at a slightly elevated (18% higher) risk, and those born to mothers 40-49 years of age were at a much more elevated (69% higher) risk. Among whites, the higher neonatal mortality associated with a maternal age of 35-39 was mostly due to an increased prevalence of low birth weight; among blacks, it was due to higher birth-weight-specific risks. Neither white nor black postneonatal mortality risks were much elevated until a maternal age of 40-49, and this last elevation was mostly due to higher birth-weight-specific risks. These findings suggest that infertility and fetal mortality aside, and considering only the effect on infant mortality, it is relatively safe for women to postpone childbearing into their middle, and perhaps late, thirties.     

Second trimester trisomy 21 maternal serum marker screening. Results of a countrywide study of 854,902 patients

OBJECTIVES: In France, maternal serum marker screening is governed by specific legislation. We conducted a study of the countrywide trisomy 21 screening based on second trimester maternal serum markers. METHODS: We reviewed the medical records of 854,902 patients prospectively screened for second trimester maternal serum markers in the 60 authorized laboratories over the two-year period 1997-1998. All patients screened in France were included. The risk of trisomy 21 was calculated from the combination of maternal age and maternal serum markers. The same cut-off (1/250) was used in all laboratories. RESULTS: In 1998, 65% of pregnant women underwent maternal serum screening. In the 837,765 patients under 38 years of age who were screened, 54,321 (6.48%; 5% CI 6.42-6.53%) had a calculated risk >1/250. Of the 884 Down syndrome cases observed, 626 were detected by maternal serum markers (70.8%; 5% CI 67.8-73.8%). These good results can be explained by a strict quality control of all steps. For the 13,891 patients over 38 years of age, the Down syndrome detection rate was 98.9% for a 34% false-positive rate. CONCLUSIONS: Strict rules covering prenatal trisomy 21 screening are of benefit to patients, practitioners and laboratories alike, and ensure good quality control, a high trisomy 21 detection rate and a low amniocentesis rate.     

554751例孕妇妊娠中期血清学唐氏筛查结果分析

目的:分析妊娠中期血清学唐氏筛查结果与预产期年龄、体质量及不良妊娠结局的相关性,从而为临床诊断和预测提供参考依据。方法:通过河南省妇幼健康信息管理平台选取河南省18个地市1697家医院2017年进行唐氏筛查检查并结束妊娠的554751例孕妇作为研究对象,根据唐氏筛查结果将孕妇分为唐氏筛查低风险组(对照组)、临界风险组及高风险组,对不同风险组的预产期年龄、体质量及流产、早产、足月小样儿的发生率进行统计分析。结果:①孕妇的预产期年龄及体质量与唐氏筛查的结果具有相关性,预产期年龄在20~34岁之间的孕妇,随着年龄的增加,21-三体及18-三体风险异常的孕妇所占比例也随之增加;与对照组相比,观察组孕妇筛查时的体质量增加,差异有统计学意义(P<0.05);②21-三体和18-三体异常组和对照组的流产、早产及足月小样儿的发生率比较,差异无统计学意义(P>0.05);神经管缺陷(NTD)高风险组孕妇的流产、早产及足月小样儿的发生率均高于对照组,差异有统计学意义(P<0.05)。结论:妊娠中期血清学唐氏筛查不仅可以对胎儿非整倍体染色体及NTD进行筛查,还可以作为预测不良妊娠结局的辅助检查,尤其是NTD高风险的孕妇,并且对胎儿出生缺陷的预防也具有指导意义。     

The relationship between utilization of prenatal care and Down syndrome live births

Objective. This study evaluated whether utilization of prenatal care, as measured by the Kessner index, affects the number of Down syndrome live births.

Methods. A retrospective analysis of birth certificate data of Down syndrome live births comparing 1989 to 2001 by year, maternal age, gestational age at first prenatal visit, and adequacy of prenatal care according to Kessner categories of adequacy of prenatal care.

Results. Down syndrome live births were inversely correlated with adequacy of prenatal care. Reductions in Down syndrome live births were seen in all categories of prenatal care in all age groups. In 2001 a minimum 30% reduction was seen in any category rising to a 58% reduction in women ≥35 years with adequate prenatal care. The largest reductions were seen in women ≥35 years of age.

Conclusions. Reductions in Down syndrome live births occurred in all age groups between 1989 and 2001. Utilization of prenatal care as measured by the Kessner index was associated with reductions in Down syndrome live births, with a greater reduction in women ≥35 years of age.     

妊娠合并甲状腺功能亢进症患者抗甲状腺药物治疗后对其新生儿先天畸形的影响

目的探讨妊娠合并甲状腺功能亢进症（甲亢）患者抗甲状腺药物（ATDs）治疗对其新生儿先天畸形的影响。方法采用回顾性分析方法对1983年1月1日-2003年12月31日在北京协和医院分娩的100例妊娠合并甲亢患者及其101例新生儿的临床资料进行研究。根据妊娠合并甲亢患者的甲状腺功能（甲功）状态及服用ATDs的情况对其新生儿先天畸形发生率、影响因素进行分析。结果（1）妊娠合并甲亢患者分娩的101例新生儿中,合并先天畸形7例,新生儿先天畸形发生率为6．9％,显著高于同期出生的新生儿先天畸形发生率的0．9％（212／22765）。其相对危险性为同期出生新生儿的7．9倍（P〈0．01）。（2）101例新生儿中,其母孕早期合并甲功亢进52例,新生儿先天畸形5例,先天畸形发生率为9．6％（5／52）;其母孕早期甲功正常49例,新生儿先天畸形2例,先天畸形发生率为4．1％（2／49）,两者新生儿先天畸形发生率比较,差异无统计学意义（P〉0．05）。（3）其母孕早期服用甲巯咪唑的12例新生儿中,合并新生儿先天畸形5例,先天畸形发生率为41．7％;其母孕早期服用丙基硫氧嘧啶的28例新生儿中,合并新生儿先天畸形1例,先天畸形发生率为3．6％;其母孕早期未服用ATDs的61例新生儿中,合并新生儿先天畸形1例,先天畸形发生率为1．6％。3者之间新生儿先天畸形发生率比较,差异有统计学意义（P〈0．01）。其中服用甲巯咪唑患者的新生儿先天畸形发生率显著高于服用丙基硫氧嘧啶者（P〈0．01）和未用药者（P〈0．01）。妊娠合并甲亢孕早期服用甲巯咪唑患者新生儿发生先天畸形的危险性,为服用丙基硫氧嘧啶患者的19．3倍;为未服用ATDs患者的42．9倍。对数线性模型分析显示,妊娠合并甲亢患者孕早期服用不同种类的ATDs,对新生儿先天畸形的形成存在显著的差异（P=0．0003）。结论妊娠合并甲亢患者其新生儿发生先天畸形的危险性增加。妊娠合并甲亢患者孕早期服用甲巯咪唑可能是导致新生儿先天畸形的主要因素之一。因此,妊娠合并甲亢患者应避免选用甲巯咪唑,以减少发生新生儿先天畸形的危险性。     

Long-term trends for socio-economic differences in prenatal diagnosis of Down syndrome: diffusion of services or persistence of disparities?

Objective  To assess long-term trends in disparities for prenatal diagnosis of Down syndrome in relation to policy changes.
Design  Population-based observational study.
Setting  Paris.
Population  Residents of Paris who gave birth or had a termination of pregnancy in Paris during 1983–2003 (approximately 23 000 births per year).
Methods  Using population-based data from the Paris Registry of Congenital Malformations on 1934 cases of Down syndrome, we assessed differences in prenatal diagnosis proportions by maternal profession and geographical origin for the years 1983–2003. Analyses included locally weighted scatter plot smoother curves and binomial regression.
Main outcome measure  Trends in proportion of Down syndrome cases diagnosed prior to birth for different maternal occupation groups and women of different geographical origins.
Results  The proportion of prenatally diagnosed cases increased substantially, reaching to about 85–90% of cases in 2003 for most socio-economic groups. This increase was accompanied by a significant decrease in disparities in prenatal diagnosis. Nonetheless, the proportion of prenatally diagnosed cases remained 12% lower for women without a profession compared with those in the highest occupational category (maternal age-adjusted risk difference −12.0%, 95% CI −17.1 to −6.9).
Conclusions  Together with the implementation of policies aimed at providing access to prenatal screening for all women, socio-economic differences in prenatal diagnosis of Down syndrome decreased over time. These trends need to be monitored, particularly in light of technical advances and alternative strategies for prenatal testing. However, while monitoring the proportion of cases with prenatal diagnosis is important, the ideal evaluation of prenatal testing programmes should also include measures of informed choice.     

Second trimester maternal serum screening using alpha fetoprotein, free beta human chorionic gonadotropin and maternal age specific risk: result of chromosomal abnormalities detected in screen positive for Down syndrome in an Asian population.

BACKGROUND: This study was to determine the incidence of chromosome abnormalities in Taiwanese women undergoing prenatal chromosome analysis after a second trimester Down syndrome screening by using maternal age and serum dual-marker testing (alpha-fetoprotein and free-beta unit human chorionic gonadotropin). METHODS: A total of 10,098 Taiwanese women with pregnancy between 15 and 23 weeks' gestation received second-trimester Down syndrome risk evaluation by dual-marker and maternal age specific risk testing in a single medical center. The study took 22 months. Ninety-seven percent of this study population was less than 34 years old. Ninety-six percent of our cases were screened between 15-20 weeks of gestation. This population was included only after a routine ultrasonography scan for correction of gestational age and exclusion of major structural anomalies. By using an algorithm to detect Down's syndrome, with a risk of 1:270 as a cut-off value, 816 patients were screen-positive for Down syndrome (screen-positive rate 8.0%). Karyotypes were reviewed for 670 (82.1%) mothers who received prenatal karyotype analysis. RESULTS: Twelve cases of Down syndrome were identified in the screen positive group with an estimated detection rate of 67% (false positive rate 8%). Three cases of Down syndrome were detected in late trimester among the screen-negative group. Seven other fetal chromosome abnormalities were also found among the screen-positive pregnancy. In addition, seven cases were screen-positive for trisomy 18; all of these patients received amniocentesis and only one case was confirmed. CONCLUSION: These findings indicate that this screening program combining alpha-fetoprotein (AFP), free beta human chorionic gonadotropin (free-hCG) and maternal age-specific would achieve a screening efficiency in Taiwanese populations as comparable to those obtained in Caucasian populations. Our results also suggest that approximately 3% of pregnancies with a positive dual marker and maternal age-specific screen results will have a chromosome abnormality despite having a normal routine ultrasound scan. Mothers with positive screening results should be made aware of the implications of a positive result.     

Womens' preference in Down syndrome screening

OBJECTIVE: To determine the knowledge of pregnant women about prenatal tests, and what tests they would choose if offered. Also, the preference of pregnant women for second-trimester or first-trimester screening was assessed. PATIENTS AND METHODS: Pregnant women receiving antenatal care in a decentralized primary care system (n=80), and pregnant women that were offered a prenatal diagnosis at the Academic Medical Centre (n=195), were asked to complete a questionnaire. RESULTS: The response rate was over 80%. Most women in both groups preferred a screening test for Down syndrome to be performed in the first trimester of pregnancy. A combination of nuchal translucency measurement and first-trimester serum screening was the option of choice. The screening possibilities for Down syndrome were less well known to the women in the low-risk group compared with the women in the high-risk group. The offer of a prenatal screening test would have been declined by more than 30% of women at low risk for carrying a fetus with Down syndrome. CONCLUSIONS: Our results show that women prefer screening for Down syndrome to be performed in the first trimester of pregnancy, using both serum and ultrasound tests. In women at low risk for Down syndrome the knowledge of prenatal screening methods was less, as well as the acceptance of prenatal screening being lower.     

How do women of diverse backgrounds value prenatal testing outcomes?

OBJECTIVES: To describe women's preferences for prenatal testing outcomes and to explore their association with sociodemographic characteristics and attitudes. METHODS: We conducted a cross-sectional study of 584 racially/ethnically and socioeconomically diverse pregnant women aged 16 to 47 years recruited from 23 San Francisco Bay Area practices. We assessed preferences for 12 potential prenatal testing outcomes using the time trade-off metric for all outcomes and the standard gamble metric for two outcomes. Preferences were calculated on a scale of 0 (death) to 1 (perfect health). Participants also completed a sociodemographic and attitude survey. RESULTS: Highest preference scores were assigned to outcomes resulting in the birth of a chromosomally normal infant (mean = 0.91-0.93; median = 0.99-1.00). Lower scores were obtained for outcomes involving pregnancy loss (mean = 0.69-0.87; median = 0.76-0.92), which were correlated with attitudes regarding miscarriage, pregnancy termination, and Down syndrome. The lowest scores were assigned to Down syndrome-affected births (mean = 0.67-0.69; median = 0.73-0.75), which also were correlated with attitudes toward Down syndrome. We did not find a statistically significant relationship between participants' preference scores and age. CONCLUSION: Preferences for prenatal testing outcomes vary according to the pregnant women's underlying attitudes about pregnancy loss and Down syndrome, and not according to her age. Current age/risk-based guidelines should account for individual variation in patient preferences.     

Maternal education modifies the age-related increase in the birth prevalence of Down syndrome

OBJECTIVE: To test the hypothesis that the age-related increase in the birth prevalence of Down syndrome is less for women with higher levels of education due to their more frequent use of prenatal diagnosis. METHODS: We compared the effects of maternal age on the odds of Down syndrome at birth, and on amniocentesis use, in women with <12 years of education with those who had >or=12 years of education. We used a national data set and analyzed the effects of education separately for African Americans (N = 1643054), and non-Hispanic whites (N = 6676885) in the US birth cohorts of 1989-1991. Analyses included Mantel-Haenszel and logistic regression models with the likelihood ratio test to assess interactions between education and age effects. RESULTS: For both African Americans and non-Hispanic whites, the age-related increase in the odds of Down syndrome was substantially less for women with higher levels of education (p < 0.001). For both ethnic groups, women with higher levels of education were more likely to use amniocentesis (p < 0.001). CONCLUSIONS: Our results suggest that women with higher levels of education are more likely to use prenatal diagnosis. Moreover, this effect of education on prenatal diagnosis use, translates into a lower rate of age-related increase in the birth prevalence of Down syndrome.     

Second-trimester genetic sonography in patients with advanced maternal age and normal triple screen

OBJECTIVE: To estimate the value of second-trimester genetic sonography in detecting fetal Down syndrome in patients with advanced maternal age (at least 35 years) and normal triple screen. METHODS: Since July 1999, a prospective collection and recording of all individual triple screen risks for fetal Down syndrome was initiated for all patients with advanced maternal age presenting in our ultrasound unit for second-trimester genetic sonography. Genetic sonography evaluated the presence or absence of multiple aneuploidy markers. Outcome information included the results of genetic amniocentesis, if performed, and the results of pediatric assessment and follow-up after birth. RESULTS: By June 2001, 959 patients with advanced maternal age and normal triple screen were identified. Outcome information was obtained in 768 patients. The median risk for fetal Down syndrome based on maternal age was 1:213 (range 1:37-1:274). The median risk for fetal Down syndrome based on triple screen results was 1:1069 (range 1:275-1:40,000). A total of 673 patients had normal genetic sonography, and none (0%) had Down syndrome; 95 had one or more aneuploidy markers present, and four (4.2%) had fetuses with Down syndrome. The triple screen risks for these four fetuses ranged from 1:319 to 1:833. CONCLUSION: This study suggests that patients with advanced maternal age and normal genetic sonography carried very little risk for Down syndrome. The use of genetic sonography may increase the detection rate of fetal Down syndrome in this group of pregnant women.     

Do women know that prenatal testing detects fetuses with Down syndrome?

This questionnaire-based study in Victoria, Australia, examined the responses of pregnant women, aged 37 years and over, to a question about what they expected prenatal testing (screening and/or diagnosis) for birth defects to tell them about their pregnancy. Content analysis showed that, of the 432 tested women, 61.3% mentioned Down syndrome, chromosomal abnormalities or trisomies. Women undergoing both screening and diagnosis were more likely than those having one or other test to mention Down syndrome (adjusted OR = 1.6, P = 0.06), having adjusted for age, marital status, education, residence and parity. Similarly, those from an English-speaking background were more likely to mention Down syndrome, etc. compared to women from a non-English-speaking background (adjusted OR = 3.5, P < 0.001). Down syndrome, a fundamental piece of information about prenatal tests, was not mentioned in nearly 40% of women's responses. This suggests that pregnant women need clearer information about prenatal testing, including the conditions that might be detected.