Twenty-year trends in prevalence and survival of Down syndrome

The aims of this study were (1) to determine trends in total prevalence and live birth prevalence of Down syndrome, (2) to analyse trends in factors likely to influence this prevalence and (3) to determine 1-year survival in Down syndrome. A retrospective review was made of prospectively collected data on all cases of Down syndrome within a malformation registry born in 1985-2004. Down syndrome affected 1188 pregnancies among 690 215 live births (1.72 per 1000 total births). The proportion increased over 20 years from 1.3 to 2.5 per 1000 total births (P<0.0001). There were 389 terminations for Down syndrome and 51 stillbirths. There were 748 live births with Down syndrome (1.08 per 1000 live births). The live birth prevalence declined in 1985-1994 and increased in 1995-2004 with no overall change. Total live births in the population declined by 20% over 20 years. Mothers delivering at 35 years of age or above increased from 6 to 15%. The uptake of maternal serum screening increased from zero in 1987 to 35% in 1993 but then plateaued. One-year survival of live births with Down syndrome increased, especially in babies with cardiovascular malformations, reaching almost 100%. The prevalence of pregnancies affected by Down syndrome has increased significantly, but there has been no overall change in live birth prevalence. Increasing maternal age and improved survival of children with Down syndrome have offset the effects of prenatal diagnosis followed by the termination of pregnancy and declining general birth rate.     

Projected number of children with isolated spina bifida or down syndrome in England and Wales by 2020

Children with major congenital anomalies often require lifelong access to health and social care services. Estimating future numbers of affected individuals can aid health and social care planning. This study aimed to estimate the number of children aged 0–15 years living with spina bifida or Down syndrome in England and Wales by 2020. Cases of spina bifida and Down syndrome born during 1998–2013 were identified from the Northern Congenital Abnormality Survey and the National Down Syndrome Cytogenetic Register, respectively. The number of infants born with spina bifida during 1998–2019 were estimated by applying the average prevalence rate in the North of England to actual and projected births in England and Wales. Poisson regression was performed to estimate the number of infants born with Down syndrome in England and Wales during 1998–2013 and 2004–2019. The numbers of children aged 0–15 living with spina bifida or Down syndrome in 2014 and in 2020 were then estimated by multiplying year- and age-specific survival estimates by the number of affected births. An estimated 956 children with isolated spina bifida, 623 children with spina bifida and hydrocephalus and 11,592 children with Down syndrome aged 0–15 years will be living in England and Wales by 2020, increases of 7.2%, 12.0% and 12.7% since 2014, respectively. Due to improvements in survival, an increase in population size and changes in maternal age distribution at delivery, we anticipate further increases in the number of children living with spina bifida or Down syndrome by 2020.     

Changing trend in congenital abdominal wall defects in eastern region of Ireland

In the past six years, there have been reports from abroad of an unexplained rise in the birth prevalence rate of the congenital abdominal wall defect gastroschisis, while rates for the macroscopically similar anomaly omphalocoele have remained stable. The Dublin EUROCAT Registry of congenital anomalies monitors trends in the birth prevalence of birth defects in the eastern region of Ireland. We analysed births of children with omphalocoele and gastroschisis born in the period 1981-2000, with comparisons of a number of demographic and obstetric variables. During the 20 year period the birth prevalence rate for omphalocoele remained stable at 2.5/10,000 births, whereas the rate for gastroschisis increased significantly during the 1990s from 1.0/10,000 in 1991 to 4.9/10,000 in 2000. Most of the increase occurred among mothers under 25 years of age. Omphalocoele was associated with a relatively high proportion of other major congenital anomalies. This study showed that there has been an unexpected rise in the birth prevalence of gastroschisis in the region, similar to that experienced in other countries in the same time period and likely to have common aetiological features.     

Prevalence and forms of congenital anomalies in twins born in Pomeranian District during the period from 1.07.1997 to 31.12.1998. Polish Register of Congenital Anomalies

The authors have analysed the frequency and structure of congenital anomalies in children born in the Pomeranian district in the period from 01.07.1997 to 31.12.1998. Among a total of 28.361 births in that area, 748 (2.64%) were affected by congenital anomalies. Among 28.361 births, 620 (2.18%) were from multiple pregnancies. 23 (3.71%) among births from multiple pregnancies were affected by congenital malformations. The prevalence rate of inborn anomalies in births from multiple pregnancy in our area were higher (3.71%) in comparison to births from singleton pregnancy (2.61%). It implies that children born from multiple pregnancy are at higher risk of developing congenital anomalies.     

Epidemiology of orofacial clefts in a Danish county over 35 years – Before and after implementation of a prenatal screening programme for congenital anomalies

In 2004 the Danish National Board of Health changed its screening recommendations. Since 2005 a first trimester screening for Down syndrome and a prenatal ultrasound screening for congenital anomalies in the second trimester of pregnancy has been offered to all pregnant women.The aim of this study was to describe the prevalence of cleft lip with or without cleft palate and cleft palate in a Danish area and to describe associated anomalies and the development in prenatal diagnosis over time. The study was based on data from the EUROCAT Registry for Funen County. The registry is based on multiple data sources and includes information about live births, fetal deaths with a gestational age >20 weeks and terminations of pregnancy after prenatal diagnosis of severe fetal anomaly. The study included all fetuses/infants out of a population of 182,907 births diagnosed with orofacial clefts born between 1980 and 2014. There were 271 cases diagnosed with cleft lip with or without cleft palate and 127 cases diagnosed with cleft palate, giving a prevalence of 14.8 per 10,000 births for cleft lip with or without cleft palate and 6.9 per 10,000 births for cleft palate. There were no significant changes in prevalence over time for the two anomalies, calculated with and without inclusion of genetic and chromosomal cases. Overall 66 cases were diagnosed prenatally (17% of total). For isolated cleft lip with or without cleft palate none of the 157 cases born before 2005 were diagnosed prenatally compared to 34 of 58 cases (59%) born in 2005–2014 (p?<?0.01). The proportion of liveborn infants with multiple congenital anomalies also changed after 2005 with 15% (39/266) of all liveborn infants with orofacial clefts born 1980–2004 having multiple anomalies compared to 7% (7/96) in 2005–2014 (p?<?0.05).The implementation of the new screening programme in 2005 has given a major change in prenatal detection rate and reduced the proportion of liveborn infants with orofacial clefts classified as multiple congenital anomaly cases. The prevalence of cleft lip with or without cleft palate was higher than reported from many other countries.     

Associated anomalies in Pierre Robin sequence

Pierre Robin sequence (PRS) is frequently co-occurring with other non-PRS congenital anomalies. The types and the prevalence of anomalies co-occurring with PRS vary in the reported studies. The aims of this report was to study the types and the prevalence of the anomalies co-occurring with PRS in a well-studied population northeastern France. The types and the prevalence of anomalies co-occurring in cases with PRS were ascertained in all terminations of pregnancy, stillbirths and live births in 387,067 births occurring consecutively during the period 1979–2007 in the area covered by our registry of congenital anomalies which is population-based, 89 cases of PRS were registered during the study period with a prevalence of 2.29 per 10,000 births, 69.7% of the cases had associated non-PRS anomalies. Chromosomal abnormalities were present in 10 (11.2%) cases including three 22 q11.2 deletion. Non-chromosomal recognizable conditions were diagnosed in 27 cases (30.3%) including 10 Stickler syndrome, 8 Treacher Collins syndrome, 3 cases with short stature and 6 other syndromes. Multiple congenital anomalies (MCA) were present in 25 cases (28.1%). The most frequent MCA were in the ear, face and neck (35 out of 98 anomalies, 35.7%), cardiovascular (18 anomalies, 18.4%), musculoskeletal (11 anomalies, 11.2%), central nervous (7 anomalies, 7.1%), urinary (6 anomalies, 6.1%), and eye (6 anomalies, 6.1%) system. The high prevalence of associated anomalies justifies a thorough screening for other congenital anomalies in cases with PRS.     

Down syndrome and recent demographic trends in Manitoba.

Two hundred and thirty-three children born in Manitoba with Down syndrome between 1965 and 1974 were ascertained and the maternal ages obtained. Mean maternal age was found to have declined in this period both for all livebirths and to a greater extent for Down syndrome children. Though the proportion of mothers of Down syndrome infants with a maternal age of less than 35 years remained the same, the proportion of mothers aged 35 to 39 years increased and the age specific incidence of Down syndrome became significantly greater for women in this age group. Reduction in the proportion of Down syndrome births to women over 40 years and the increased incidence of Down syndrome in children of women aged 35 to 39 years has important consequences for the planning of amniocentesis programmes.     

Amniotic band syndrome and limb body wall complex in Europe 1980–2019

Amniotic band syndrome (ABS) and limb body wall complex (LBWC) have an overlapping phenotype of multiple congenital anomalies and their etiology is unknown. We aimed to determine the prevalence of ABS and LBWC in Europe from 1980 to 2019 and to describe the spectrum of congenital anomalies. In addition, we investigated maternal age and multiple birth as possible risk factors for the occurrence of ABS and LBWC. We used data from the European surveillance of congenital anomalies (EUROCAT) network including data from 30 registries over 1980–2019. We included all pregnancy outcomes, including live births, stillbirths, and terminations of pregnancy for fetal anomalies. ABS and LBWC cases were extracted from the central EUROCAT database using coding information responses from the registries. In total, 866 ABS cases and 451 LBWC cases were included in this study. The mean prevalence was 0.53/10,000 births for ABS and 0.34/10,000 births for LBWC during the 40 years. Prevalence of both ABS and LBWC was lower in the 1980s and higher in the United Kingdom. Limb anomalies and neural tube defects were commonly seen in ABS, whereas in LBWC abdominal and thoracic wall defects and limb anomalies were most prevalent. Twinning was confirmed as a risk factor for both ABS and LBWC. This study includes the largest cohort of ABS and LBWC cases ever reported over a large time period using standardized EUROCAT data. Prevalence, clinical characteristics, and the phenotypic spectrum are described, and twinning is confirmed as a risk factor.     

Descriptive epidemiology of Cornelia de Lange syndrome in Europe

Cornelia de Lange syndrome (CdLS) is a multiple congenital anomaly/mental retardation syndrome consisting of characteristic dysmorphic features, microcephaly, hypertrichosis, upper limb defects, growth retardation, developmental delay, and a variety of associated malformations. We present a population-based epidemiological study of the classical form of CdLS. The data were extracted from the database of European Surveillance of Congenital Anomalies (EUROCAT) database, a European network of birth defect registries which follow a standard methodology. Based on 23 years of epidemiologic monitoring (8,558,346 births in the 1980-2002 period), we found the prevalence of the classical form of CdLS to be 1.24/100,000 births or 1:81,000 births and estimated the overall CdLS prevalence at 1.6-2.2/100,000. Live born children accounted for 91.5% (97/106) of cases, fetal deaths 2.8% (3/106), and terminations of pregnancy following prenatal diagnosis 5.7% (6/106). The most frequent associated congenital malformations were limb defects (73.1%), congenital heart defects (45.6%), central nervous system malformations (40.2%), and cleft palate (21.7%). In the last 11 years, as much as 68% of cases with major malformations were not detected by routine prenatal US. Live born infants with CdLS have a high first week survival (91.4%). All patients were sporadic. Maternal and paternal age did not seem to be risk factors for CdLS. Almost 70% of patients, born after the 37th week of gestation, weighed 相似文献   

On monitoring the multiply malformed infant. I: Case-finding, case-recording, and data handling in a Latin American program

The methods used by the Latin American Collaborative Study of Congenital Malformations (ECLAMC) for monitoring the birth prevalence of multiply malformed infants are based on a clinical-epidemiological approach oriented to the early detection of teratogenic agents. They consist of three steps: 1) the analysis of observed vs expected rates of all congenital anomalies (CA), including their isolated and associated forms; 2) the same type of analysis applied to each multiple congenital anomaly (MCA) pattern; and 3) a clinical case presentation reserved only for those considered as true MCA because of presence of three or more independent CA. During the period 1982-1983 299,231 infants were examined. Multiply malformed infants, excluding Down syndrome cases, were born at a rate of 4/10,000, 40% having syndromes (two or more interrelated CA), 30% anomaly pairs, ie, two independent CA, and 30% true MCA cases. In a program with 150,000 births per year, as in ECLAMC, this means about five true MCA cases per week, a number easily handled individually on a clinical basis.     

基于人群监测和医院监测的高发地区出生缺陷流行病学特征比较

目的比较中国出生缺陷高发地区人群监测和医院监测出生缺陷流行病学特征的差异。方法在中国出生缺陷高发的山西省选择2个高发县作为研究地区,对该地区2002年1月1日至2004年12月31日孕满20周及以上胎儿及婴幼儿出生缺陷的发生水平进行分析。人群监测采用社区调查和医院登记相结合的方法,医院监测来自当地医院妇产科及B超检查的登记册,比较两种监测方法出生缺陷发生率及顺位,孕20周至生后7d或至3岁时的差异。结果 2002至2004年医院监测累积出生4855人,出生缺陷113例,出生缺陷发生率为232.7/万出生;人群监测累积出生6420人,出生缺陷223例,出生缺陷发生率为347.4/万出生,差异有显著统计学意义（P〈0.001）。在孕20周至生后7d的常规监测年龄段,医院和人群监测资料出生缺陷均以神经系统畸形为主,神经系统、耳部畸形、泌尿生殖系统以及皮肤缺陷发生率均为人群监测高于医院监测。人群与医院监测的前5位出生缺陷顺位一致,依次为无脑儿、脊柱裂、先天性脑积水、脑膨出、唇和（或）腭裂。当人群监测年龄延长至3岁时,出生缺陷发生率高达844.2/万出生,是孕20周至生后7d人群监测数据的2.43倍,是医院监测数据的3.63倍。人群监测孕20周至3岁时出生缺陷顺位变化较大,前5位依次为腹股沟疝、无脑畸形、先天性智力低下、先天性心脏病和脊柱裂。结论出生缺陷的水平和顺位与监测方法和时段密切相关,在常规人群出生缺陷监测基础上,可将部分出生缺陷监测时间延长至3岁,可发现更多常规监测以外的出生缺陷种类,为出生缺陷预防提供可靠依据。     

Down syndrome and maternal age in Japan, 1950–1973

The mean maternal age and the percentage age distribution of 2,650 mothers of children with Down syndrome were calculated for 1950-1973, from hospital records. Mean maternal age had dropped both for controls (28.55 leads to 27.37) and Down syndrome (31.26 leads to 29.59). The observed maternal age distributions were very similar to those expected in corresponding periods, from the age specific incidences of Collmann & Stoller (1962). It is conceivable that the fall in maternal age in Down syndrome in recent years has resulted from the general trend to decreasing maternal age. There has been no change in the age-specific incidences of Down syndrome. The incidence of Down syndrome seems to be falling in Japan.     

The prevalence of Down syndrome in County Galway

This is a retrospective survey of all cases of Down syndrome recorded between 1981 and 2000 to mothers resident in Co. Galway. The study compares the incidence of Down syndrome in both decades and examines the effects of changing demographics on incidence rates. The overall prevalence rate was 26.8/10,000 live births for the full period. Although there were 5119 fewer births in the 1991-2000 period, the prevalence was 29.8/10,000 compared to 24.1/10,000 in the previous decade. Despite the falling birth rates and fertility rates observed in our study between the two decades we found that the higher prevalence of Down syndrome in the second decade was directly related to the significant increase in the proportion of women in the 30 plus age group. Our study also found the place of the child with Down syndrome in the family changed, with 25.3% being the 5th or more child in the first decade compared with 9.5% in the second decade.     

A multi-center study for birth defect monitoring systems in Korea

The aim of this study was to establish a multi-center birth defects monitoring system to evaluate the prevalence and the serial occurrence of birth defects in Korea. Ten medical centers participated in this program. A trained nurse collected relevant records from delivery units and pediatric clinics in participating hospitals on a monthly basis. We observed 1,537 cases of birth defects among 86,622 deliveries, which included live births and stillbirths. The prevalence of birth defects was 1.8%, and the sex distribution of the birth defect cases was 55.2% male and 41.6% female. The highest proportion of birth defects was in the cardiovascular system (17.5%), followed by birth defects involving in the genitourinary system (15.6%). Chromosomal anomalies were detected 30.0 per 10,000 births. Of these chromosomal anomalies, Down syndrome was most frequently observed. This study led to an establishment of a multi-center active monitoring system for birth defects. To better understand the serial occurrence of birth defects in Korea, it is necessary to increase the number of participating hospitals and to launch on a nation-wide multi-center study.     

Associated anomalies in cases with agenesis of the corpus callosum

Agenesis of corpus callosum (ACC) is an uncommon congenital anomaly, its etiology is unclear and its pathogenesis is controversial. Cases with ACC often have other non‐ACC associated congenital anomalies. The purpose of this study was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with ACC were collected in all live births, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population‐based registry of congenital malformations. Of the 99 cases with ACC, representing a prevalence of 2.56 per 10,000, 73 (73.7%) had associated anomalies. There were 16 (16.2%) cases with chromosomal abnormalities, and 13 (13.2%) nonchromosomal recognized dysmorphic conditions including syndromes two each: Aicardi, Dandy–Walker, and fetal alcoholism. Forty‐four (44.4%) of the cases had nonsyndromic multiple congenital anomalies (MCA). Anomalies in the musculoskeletal, the urogenital, the central nervous, the cardiovascular, and the digestive systems were the most common other anomalies in the cases with MCA. The anomalies associated with ACC could be classified into a recognizable malformation syndrome in 29 out of the 73 cases (39.7%) with associated anomalies. This study included special strengths: it is population‐based, each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, three of four cases, emphasizes the need for a screening for other anomalies in cases with ACC.     

Preliminary data on changes in neural tube defect prevalence rates after folic acid fortification in South America

Several South American countries are fortifying wheat flour with folic acid. However, only Chile started in 2000 to add 2.2 mg/kg, providing 360 microg daily per capita, an acceptable dosage for preventing the occurrence of some neural tube defect (NTD) cases. ECLAMC (Spanish acronym for the Latin American Collaborative Study of Congenital Malformations) routinely monitoring birth defects in South America since 1976, surveyed the impact of this fortification. Data from 361,374 births occurred in 43 South American hospitals, distributed in five different countries, active throughout the 1999-2001 triennium, were selected from the ECLAMC network. Birth prevalence rates for three different congenital anomalies with similar expected prevalence rates, were surveyed by the Cumulative Sum Method (CUSUM) method. They were NTD, oral clefts (OC), and Down syndrome (DS). Expected values were derived from observations made in 1999, and CUSUM was applied to the consecutive series of 24 months covering years 2000 and 2001. Only one of three congenital anomaly types, NTDs, in only one of five sampled out countries, Chile, showed a significant decrease, of 31%, during the 2000-2001 biennium, corresponding to the birth of the periconceptionally fortified infants. The level of significance (P < 0.001) was reached in the 20th month after fortification started, corresponding to August 2001. This is the first observation of a significant decrease in the occurrence of NTD after folic acid food fortification in a population little influenced by confounders common in the developed world as pre-existing secular decreasing trends, and partially unregistered induced abortions.     

Prevalence of sleep-disordered breathing in children with Down syndrome: polygraphic findings in 108 children

STUDY OBJECTIVES: To assess the prevalence of sleep-disordered breathing in a nonselected group of children with Down syndrome and to determine significant predisposing factors for this condition. DESIGN: Prospective study. SETTING: Tertiary care university hospital in Madrid, Spain. PATIENTS: The study population included 108 consecutive children with Down syndrome (mean [SD] age, 7.9 [4.5] years; range, 1-18 years) independently of whether or not suggestive clinical features of sleep-disordered breathing were present. INTERVENTIONS: In addition to history, physical examination, and lateral radiographs of the nasopharynx, all participants underwent an overnight cardiorespiratory polygraphy at the hospital using a portable ambulatory device (Apnoescreen II plus). An apnea-hypopnea index of at least 3 was required for defining the presence of sleep-disordered breathing. RESULTS: The prevalence of sleep-disordered breathing was 54.6%, with a significantly higher prevalence in boys (64.7%) than in girls (38.5%) (P < .05). The group with sleep-disordered breathing was significantly younger (6.4 [3.9] years) than those with normal polysomnographic recordings (9.6 [4.6] years) (P < .001). In the multivariate analysis, age (less than 8 years old) (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.40, 8.06); male sex (OR, 3.32; 95% CI, 1.32, 8.12); and tonsillar hyperplasia (OR, 5.24; 95% CI, 1.52, 19.03) were significantly associated with sleep-disordered breathing. Body mass index, adenoid hyperplasia, previous tonsillectomy or adenoidectomy, congenital heart disease, malocclusion, and macroglossia did not affect the prevalence of sleep-disordered breathing. CONCLUSIONS: The prevalence of sleep-disordered breathing in children with Down syndrome is very high, particularly in boys. Tonsillar hyperplasia may play a role in the pathophysiology of sleep-disordered breathing in these patients. Adenoid hyperplasia, obesity, and congenital heart disease were not important risk factors for sleep-disordered breathing.     

Associated anomalies in cases with achondroplasia

Associated congenital anomalies may be observed in cases with achondroplasia. The prevalence reported in the literature and the types of co-occurring congenital anomalies are variable between the reported studies. The aim of this study was to establish the prevalence and to describe the associated anomalies in cases with achondroplasia. This study included 25 cases ascertained from our registry of congenital anomalies including all terminations of pregnancy, stillbirths and live births between 1979 and 2007 in 387,067 consecutive births (the prevalence of achondroplasia was 6.4 per 100,000 births), and 223 cases ascertained from the French Little People organization built on the model of LPA (Little People of America, Inc.). Out of these 248 cases of achondroplasia 37 (14.9%) had associated anomalies including 4 (1.6%) cases with chromosomal abnormalities (2 trisomies 21, one 22 q11.2 deletion, and one 47, XXX), 2 (0.8%) cases with recognizable non-chromosomal conditions (one Moebius syndrome and one Pierre Robin sequence) and 31(12.5%) cases with MCA (multiple congenital anomalies). The 31 cases with MCA had 45 anomalies. Anomalies in the urogenital system (24.4%), the cardiovascular system (20.0%), the musculoskeletal system (15.5%), the central nervous system (11.1%), the eye (11.1%), and the orofacial system (8.8%) were the most common MCA. The overall prevalence of associated anomalies shows that the individuals with achondroplasia need a careful screening for other congenital anomalies.     

Atrioventricular canal defect without Down syndrome: a heterogeneous malformation.

The atrioventricular canal defect (AVCD) is one of the congenital heart defects most frequently associated with extracardiac anomalies. The association of AVCD with Down syndrome and heterotaxy has been studied extensively. However, little information is available about the prevalence of genetic syndromes and additional cardiac malformations in patients with AVCD and visceroatrial situs solitus without Down syndrome. This paper reviews the genetic and cardiologic characteristics of patients with non-Down AVCD and situs solitus in the literature and our series of 203 consecutive patients. In our experience, 132 (65%) of the patients have nonsyndromic AVCD, while 71 (35%) have non-Down syndromic AVCD. Chromosomal imbalances were detected in 7 cases (3%), Mendelian syndromes or associations in 44 (22%), and extracardiac anomalies without an identifiable syndrome in 20 (10%). Deletion 8p is prevalent among those with chromosomal imbalances. Noonan, Ellis-van Creveld, oro-faciodigital, Smith-Lemli-Opitz syndromes and VACTERL cases are frequent among patients with recognizable or identifiable nonchromosomal conditions. Based on this analysis of the type of AVCD and prevalence of associated cardiac anomalies in the different groups of patients, we found that: 1) the complete form is prevalent in patients with chromosomal imbalances; 2) the complete form is more frequently associated with additional cardiac defects, mainly left side obstructive lesions; and 3) additional cardiac anomalies are prevalent in syndromic patients. In conclusion, AVCD is a congenital heart defect with great variability in the anatomic patterns and heterogeneity of causes also in the subset without Down syndrome and without heterotaxy. The peculiar anatomic subtypes of this cardiac defect are associated with specific genetic conditions.     

Live births,natural losses,and elective terminations with Down syndrome in Massachusetts

PurposeNo studies to date have reported an estimated number of live births, elective terminations, and natural losses (miscarriages and stillbirths) for Down syndrome (DS) in Massachusetts (MA). These numbers would be helpful to estimate how many expectant parents of children with DS need support and the number of live-born children with DS who require services.MethodsCombining robust data sets, including the Annual Reports of the MA Birth Defects Monitoring Program, we estimated the number of live births, elective terminations, and natural losses with Down syndrome from 1900 to 2010.ResultsThe live birth prevalence for DS in MA for the most recent years for which data are available (2006–2010) was estimated at 12.4 per 10,000 live births, with a total of approximately 94 live births annually. During this period, an estimated 126 DS-related elective pregnancy terminations were performed in MA annually. As of 2008, the estimated rate at which live births with DS was reduced as a consequence of DS-related elective pregnancy terminations was 49%.ConclusionThe reduction of live births with DS is significantly higher in MA than in the rest of the United States as a whole. However, ethnic and racial differences in reduction rates were similar—highest for Asians/Pacific Islanders, followed by non-Hispanic whites, non-Hispanic blacks/Africans, and Hispanics.