Frequency Of Down Syndrome Research Articles

Congenital Duodenal Obstruction: National Trends in Management and Outcomes during the Last Quarter of a Century in Norway.

During the last quarter of a century, new surgical techniques in neonates have been introduced, and neonatal intensive care has developed. Few studies have explored the implementation of new techniques and if outcomes in neonates undergoing gastrointestinal surgery have improved in the last decades. Therefore, this study aimed to investigate possible changes in postoperative outcomes and surgical techniques in all neonates operated for congenital duodenal obstruction (CDO) 1995 to 2020 in Norway. This is a national multicenter retrospective study of all neonates undergoing surgery for CDO in Norway from 1995 to 2020. Results from three periods (1995-2003, 2004-2012, and 2013-2020) were compared. The study was approved by the local data protection officers (2020/13386) and (2020/15125). We included 186 patients: 41 in period 1 (1995-2003), 83 in period 2 (2004-2012), and 62 in period 3 (2013-2020). Seventy (38%) neonates had Down syndrome and 104 (62%) had additional malformations/disorders. Birth weight, gender, frequency of Down syndrome, and other malformations/disorders did not differ between the three periods. We observed an increased rate of prenatal diagnosis throughout the study period (p < 0.001). The only change in surgical technique was the increased use of transanastomotic feeding tubes (p < 0.001). Length of stay, postoperative complication rate, days with parenteral nutrition, and 30-day mortality rate were stable over time. Perioperative treatment and postoperative outcomes in neonates with CDO have been surprisingly unchanged during the last quarter of a century. Only an increased rate of prenatal diagnosis and more frequent use of transanastomotic feeding tubes were observed.

Dynamics of the incidence of congenital malformations in children in Chelyabinsk based on the results of epidemiological monitoring in 2012–2017

Congenital malformations are not only a medical, but also a serious social problem, since this pathology is a leading cause of perinatal, neonatal, and infant morbidity, disability, and mortality.Purpose. To analyze the variation dynamics in the incidence of groups of congenital malformations, the structure of congenital malformations according to the average incidence, and the consistency of changes in the incidence of individual groups of congenital anomalies in children of Chelyabinsk based on the results of epidemiological monitoring in 2012–2017.Material and methods. To assess the frequencies of congenital malformations, we used the monitoring data of the Regional Medicaland Genetic Consultation Office in Chelyabinsk for the period from 2012 to 2017, for Down syndrome (T21) from 2012 to 2018. The total number of newborns over the six-year period was 102,308, of which 2101 children were registered with congenital malformations, including live-born, stillborn children, and fetuses with malformations identified through prenatal diagnostics. Clinical data on newborns was grouped into 11 congenital malformations categories based on the International Classification of Diseases. The statistical analysis of the monitoring results was carried out using methods of descriptive statistics, samples comparisons, correlation, and cluster analysis.Results. The incidence of all registered congenital malformations in newborns in Chelyabinsk was 20.7 per 1000 births (95% CI: 17.4–25.4) during the study period. In newborns of the Chelyabinsk city in 2012–2017, the prevalence of congenital malformations of the circulatory system (42.8%), chromosomal abnormalities (11.9%), and anomalies of the musculoskeletal system (10.3%) was observed. The relative frequency of Down syndrome for the period from 2012 to 2018 ranged from 1.51‰ to 2.42‰, considering both children born with this pathology and the data on prenatal diagnostics.Conclusion. The hierarchy of congenital malformations was reproduced from year to year with a predominance of circulatory anomalies, chromosomal anomalies, and musculoskeletal anomalies of the system. The overall incidence of all congenital malformations in Chelyabinsk in 2012–2017 does not exceed the average values for the Russian Federation, while the incidence of Down syndrome exceeded the average national level.

Characteristics and outcomes of children with ductal-dependent congenital heart disease and esophageal atresia/tracheoesophageal fistula: A multi-institutional analysis

BackgroundExtracardiac birth defects are associated with worse outcomes in congenital heart disease (CHD). The impact of esophageal atresia/trachea-esophageal fistula (EA/TEF) on outcomes after surgery for ductal-dependent CHD is unknown. MethodsRetrospective matched cohort study using the Pediatric Health Information System database from 07/2004 to 06/2015. Hospitalizations with ductal-dependent CHD and EA/TEF, undergoing CHD surgery were included as cases. Admissions with ductal-dependent CHD without EA/TEF were matched 3:1 for age at admission and Risk Adjustment for Congenital Heart Surgery-1 classification. Comparisons were performed using generalized estimating equations. ResultsThere were 124 cases and 372 controls. Cases included 32 (25.8%) low-risk, 86 (69.3%) intermediate-risk, and 6 (4.8%) high-risk patients. Cases had more females compared to controls (53.2% vs 41.1%, P = .022). Cases were more likely to be premature (28.2% vs 13.7%, P = .001) and low birth weight (29.8% vs 11.8%, P < .001). Cases had a similar frequency of Down syndrome, and DiGeorge/Velocardiofacial syndrome, but a higher frequency of anorectal malformations (4.3% vs 2.4%, P < .001) and renal anomalies (27.4% vs 9.9%, P < .001) than controls. Cases had a higher mortality on univariate (22.0% vs 8.4%, P < .001) and multivariable analysis (odds ratio 2.45, 95%, confidence interval 1.34 – 4.49). Prematurity also was significantly associated with mortality on multivariable analysis. Cases had a longer duration of mechanical ventilation, longer hospital duration of stay, and higher total cost than controls (all P < .001). ConclusionIn children with ductal-dependent CHD, EA/TEF is associated with increased morbidity, mortality and resource utilization. A majority of patients undergo EA/TEF repair prior to congenital heart disease surgery. (Surgery 2017;160:XXX-XXX.)

Frequency of down syndrome: an experience of a tertiary care diagnostic laboratory in India

Background: Down syndrome or Trisomy 21 is a genetic condition involving the presence of extra copy of chromosome 21. It is the most common chromosomal abnormality within paediatric age group. The objective of our study was to determine the frequency of Down syndrome and its various cytogenetic types in cases with clinical suspicion of Down syndrome received at the Department of Cytogenetics, Metropolis Healthcare Limited, Mumbai, India.Methods: Our study was performed on peripheral blood (2-3 ml) collected in Sodium Heparin Vacutainers obtained from 714 patients with clinical suspicion of Down syndrome. All the samples were requested for GTG staining and banding, while the cultures were set and analysed by GTG–banding at 450-550 band level. The period of our study was from January-2015 to December-2016.Results: Out of 714 samples referred, about 657 showed trisomy of chromosome 21. While, out of 657 cases, 551 (83.87%) cases were detected with free trisomy, Robertsonian translocation in 52 cases (7.91%), Mosaic pattern in 16 cases (2.44%). Our study also recorded trisomy with additional polymorphic variation in 35 cases (5.33%) and 3 cases (0.46%) with additional abnormality.Conclusions: According to the extensive literature available which states that the clinical diagnosis of Down syndrome is relatively easy, it is the pattern of chromosomal aberration that is extremely important. Identification of this pattern will assist in the estimation of the possibility of recurrence risk while counselling the parents. Overall, it will benefit the couple to arrive at an informed decision and will eventually minimize the frequency of disease in the society. Moreover, it will also assist the close blood relatives to know their risk of having baby with Down syndrome. It is to be noted that since the study was performed in a tertiary care laboratory, the percentage of cytogenetic.

Birthweights and Down syndrome in neonates that were delivered after frozen-thawed embryo transfer: The 2007-2012 Japan Society of Obstetrics and Gynecology National Registry data in Japan.

AimTo evaluate the use of frozen embryos on the outcome of assisted reproductive technology (ART), a retrospective study of the Japanese Assisted Reproductive Technology Registry data during the years 2007‐2012 was conducted.MethodsA total of 124 946 singleton neonates who reached term gestation following ART from 2007‐2012, with 80 660 achieved through frozen‐thawed embryo transfer (ET) and 44 286 being achieved through fresh ET, were analyzed for their birthweights and chromosomal abnormalities.ResultsThe birthweight of the neonates from the frozen‐thawed ETs was significantly higher than that of those from the fresh ETs throughout all the study years. The frequency of Down syndrome was 0.17% for the fresh ETs and 0.13% for the frozen‐thawed ETs in the period 2007‐2012. This study showed that frozen‐thawed ETs result in a constant increase of the average birthweight between 37 and 41 weeks gestational age and lower frequencies of Down syndrome.ConclusionFrozen‐thawed ETs were comparable to the fresh ET method, with the exceptions of higher birthweights and a lower frequency of Down syndrome in the neonates that were born from frozen‐thawed ET. The increase in birthweights was not proportional to the gestational ages. This cannot be explained with any well‐known mechanism. The frequency of chromosomal abnormalities needs detailed data for analysis.

Study of the frequency of down syndrome in a north east Indian Population

Context: Down Syndrome or Trisomy 21, with three sets of chromosome number 21 is the commonest chromosomal abnormality in newborn. There are three types of Trisomy 21: Free Trisomy 21, Translocation Trisomy 21 and Mosaic Trisomy 21. Aims: The study aimed at finding the frequency of Down syndrome and its various cytogenetic types in a population from North East India. Methods and Materials: Karyotyping from G-Banded peripheral lymphocyte of patients with suspected chromosomal abnormality was done from peripheral blood and stained with Giemsa stain as per the Standard Operating Protocol of the Diagnostic Genetic Laboratory (CFDMGD). One to three ml of blood was withdrawn aseptically from each patient. 20-30 spreads were analyzed for each case. For mosaics, 30-50 spreads were studied. The slides were analysed for detection of various chromosomal abnormalities including Down syndrome (Trisomy 21). For the translocation Down Syndrome cases, parents were investigated to determine the parental carrier status. Results: 38 cases of Trisomy 21 were detected. Free Trisomy 21 was found in 92.11% cases, translocation trisomy 21 was seen in 2.63% case and Mosaic Trisomy 21 was seen in 5.26% cases. Male: female ratio was 1.38:1. Conclusions: Knowledge of the cytogenetic types has important clinical implications as it helps clinician/geneticist determine the recurrence risk in subsequent pregnancies and helps couples take an informed decision. This in turn would help in decreasing the load of the disease in society.

The impairment of lysyl oxidase in keratoconus and in keratoconus-associated disorders

Keratoconus (KC) is an eye disease characterized by the progressive thinning and protrusion of the cornea, which results in the loss of visual acuity. This disorder remains poorly understood, although recent studies indicate the involvement of genetic and environmental factors. Recently, we have found that the distribution of the cross-linking enzyme lysyl oxidase (LOX) is markedly decreased in about 63 % of keratoconic specimens. Similarly, LOX activity is significantly reduced by 38 % compared to control tissue. Nearly 70 systemic disorders have been reported in association with KC, most of them affecting the extracellular matrix. In this review we attempted to ascertain whether any KC-associated diseases exhibit signs that may reflect LOX impairment. We hypothesized that very similar changes in the extracellular matrix, particularly at the level of collagen metabolism, including LOX impairment in mitral leaflets, may reflect an association between KC and mitral valve prolapse. Moreover, this putative association is supported by the high frequency of Down syndrome in both diseases. Among other disorders that have been found to coincide with KC, we did not find any in which the LOX enzyme may be directly or indirectly impaired. On the other hand, in cases where KC is present along with other connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome and others), KC may not arise as a localized manifestation, but rather may be induced as the result of a more complex connective tissue disorder.

Congenital Anomalies in Infant with Congenital Hypothyroidism

Congenital hypothyroidism is characterized by inadequate thyroid hormone production in newborn infants. Many infants with CH have co-occurring congenital malformations. This is an investigation on the frequency and types of congenital anomalies in infants with congenital hypothyroidism born from May 2006-2010 in Hamadan, west province of Iran. The Iranian neonatal screening program for congenital hypothyroidism was initiated in May 2005. This prospective descriptive study was conducted in infants diagnosed with congenital hypothyroidism being followed up in Pediatric Endocrinology Clinic of Besat Hospital, a tertiary care centre in Hamadan. Cases included all infants with congenital hypothyroidism diagnosed through newborn screening program or detected clinically. Anomalies were identified by clinical examination, echocardiography, and X-ray of the hip during the infant's first year of life. A total of 150 infants with biochemically confirmed primary congenital hypothyroidism (72 females and 78 males) were recruited during the period between May 2006-2010. Overall, 30 (20%) infants had associated congenital anomalies. The most common type of anomaly was Down syndrome. Seven infants (3.1%) had congenital cardiac anomalies such as: ASD (n=3), VSD (n=2), PS (n =1), PDA (n=1). Three children (2.6%) had developmental dysplasia of the hip (n=3). The overall frequency of Down syndrome, cardiac malformation and other birth defect was high in infants with CH. This reinforces the need to examine all infants with congenital hypothyroidism for the presence of associated congenital anomalies.

Defectos congénitos en recién nacidos y fetos procedentes de interrupción del embarazo tras diagnóstico prenatal en el período 1982-2009

Background and objectiveThe study of congenital defects (CD) must include termination of pregnancy (TOP) for CD and evaluate risk factors that modify their frequency. Patients and methodsConsecutive series of 517 newborn and 202 TOP with CD among 38,191 childbirths, between 1982-2009 years. ResultsThe mean frequency for newborns with CD is 13.54‰ and for newborn and TOP with CD is 18.73‰. Single CD are 61.12% in newborns and 52.17% in TOP. The 18.37% of CD in newborn and 40.58% of TOP are syndromic. Mean gestational age for TOP is 17.92 weeks. Overall frequency of anencephaly is 2.62‰ for newborns and 6.77 for 10,000 for newborns and TOP. Spina bifida is 3.14 for 10,000 newborns and 5.99 for 10,000 newborns and TOP. Overall frequency of Down syndrome (DS) is 10.74 for 10,000 newborns and 22.14 for 10,000 newborns and TOP. The percentage of foreign mothers was 35.9% in 2009 and the mean maternal age significantly increased in this period. ConclusionWe observe a significant decrease of CD in newborns but not in their conception. We have not detected primary prevention for neural tube defects. The decrease in DS in newborns is not statistically relevant but ethnic diversity and maternal aging may be modifying the frequency. The 53% of CD were TOP in the period 2007-2009. It is mandatory a complete study for CD in TOP in order to offer serious reproductive counselling.

The consequences of consanguinity on the rates of malformations and major medical conditions at birth and in early childhood in inbred populations

The rate of malformations and major medical conditions in early childhood was analyzed in a single village according to the degree of relationship between the parents. In the village, 70-80% of the marriages are between descendants of the founders and therefore consanguineous. In the period 1992-2003, in 99 of 2,610 children, a major malformation was diagnosed at birth and seven additional fetuses were aborted because of a severe malformation. A significant medical condition was diagnosed in 38 additional children in early childhood. The total of 144 cases with malformations or a major medical condition represented 5.52% (95% CI: 4.64-6.4) of the live births. Three malformations/disorders were relatively frequent: Down syndrome, esophageal atresia, and profound deafness. The rate of malformations and significant medical conditions was 7.77% (95 CI: 5.68-9.86) when the parents were first cousins and 3.63% (95% CI: 2.11-5.15) when they were not related (P = 0.002, Fisher's exact test). Offspring of parents that were second cousins or closer but less than first cousin had a risk that was similar to the one of offspring of couples that were more distantly related. We propose therefore, that in inbred populations, all the couples that are not related as first cousins but in which the spouses are both descendants of the founders should be considered as related. The high prevalence of profound deafness in the village is due to mutations in the Connexin 26 gene, while the relatively high frequency of Down syndrome is not explained by maternal age only.

Vigilancia epidemiológica del síndrome de Down en Chile, 1972 a 2005

There are some records shrowing that the frequency of Down syndrome is experiencing an increase over time. To verify whether the frequency of Down syndrome is increasing in the maternity of the University of Chile Clinical Hospital, or in other Chilean hospitals participating in the Latin American Collaborative Study of Congenital Malformations (ECLAMC) and compare the rates with other world registries of congenital malformations. The information was obtained from the ECLAMC databases of the maternity. The Down syndrome incidence rates were calculated from 1997 to 2005 and rate curves were constructed. The overall rate of Down syndrome was 3.36 per 10,000 born alive. This rate experienced a significant increase in the study period. These rates differ in the different Chilean regions, being higher in Santiago and lower in the Southern regions of the country. The mean age of mothers of newborns with or without Down syndrome was 36+/-6 and 29+/-6 years, respectively, p >0.001. The rates of newborns with Down syndrome increased in the period 1972-2005, bearing a close relationship with the increase in maternal ages.

OP01.19: The frequency of Down syndrome (DS) markers in a high‐risk population

OP01.19: The frequency of Down syndrome (DS) markers in a high‐risk population

Lens Defects and Age-Related Fiber Cell Degeneration in a Mouse Model of Increased AβPP Gene Dosage in Down Syndrome

Early-onset cataract and Alzheimer's disease occur with high frequency in Down syndrome (trisomy 21), the most common chromosome duplication in human live births. Previously, we used in vivo and lens organ culture models to demonstrate Alzheimer pathophysiology in oxidative stress-related lens degeneration. Currently, well-characterized Alzheimer transgenic mouse models are used to extend these findings. Here, we report on mice carrying a complete copy of a wild-type human AbetaPP (hAbetaPP) gene from the Down syndrome critical region on chromosome 21. hAbetaPP mice produce fiber cell membrane defects similar to those described in human cataracts and increased age-related lens degeneration. hAbetaPP expression and mRNA alternative splicing in human and mouse lens and cornea favor longer, potentially more amyloidogenic forms. Endogenous mouse AbetaPP expression is increased in transgenic lenses, consistent with the cycle of oxidative stress proposed in the mechanism of Alzheimer pathophysiology. Alternative splicing previously designated as neuron-specific occurs in human lens and cornea, and is maintained by hAbetaPP expressed in mouse tissues. These present data implicate AbetaPP in fiber cell formation and in early-onset cataracts in Down syndrome. Finally, our findings provide further support for our hypothesis that Alzheimer pathophysiology contributes to the cataract formation that is increasing in the aging population.

Malformaciones invalidantes en Chile.: Estudio ECLAMC, 1982-1997

The ECLAMC (Estudio Colaborativo Latinoamericano de Malformaciones Congénitas) is an epidemiological surveillance program for congenital defects that operates in Chile since 1969.To communicate the frequency of disabling congenital defects in Chile in the period 1982-1997.A review of the ECLAMC registry, choosing 12 congenital defects: amelia, limb amputations, limb reductions, arthrogryposis, hip luxation and subluxation, spina bifida, hydrocephaly, microcephaly, cephalocele, talipes equinovarus, Down syndrome and multiple abnormalities.In the study period, 283,403 births occurred and 7,917 newborns were malformed (7,654 born alive and 263 stillbirths). The congenital defects prevalence rates appeared higher in Chile than in other Latin American countries, specially among stillbirths. Among the studied maternity hospitals, the Clinical Hospital of the University of Chile, showed the higher prevalence of congenital defects. Rancagua and the Navy Hospital in Valparaiso have a high frequency of Down syndrome. Global rates in Chile and in the rest of ECLAMC for specific defects, do not have significant differences, except for hip subluxation, that has a lower incidence in Chile.The ECLAMC allows to have a good knowledge of the prevalence of congenital malformations in Latin America.

Burden of genetic disorders in India.

India, like other developing countries, is facing an accelerating demographic switch to non-communicable diseases. In the cities congenital malformations and genetic disorders are important causes of morbidity and mortality. Due to the high birth rate in India a very large number of infants with genetic disorders are born every year almost half a million with malformations and 21,000 with Down syndrome. In a multi-centric study on the causes of referral for genetic counselling the top four disorders were repeated abortions (12.4%), identifiable syndromes (12.1%), chromosomal disorders (11.3%) and mental retardation (11%). In a more recent study in a private hospital the top reasons for referral were reproductive genetics (38.9%)--comprising prenatal diagnosis, recurrent abortions, infertility and Torch infections--mental retardation +/- multiple congenital anomalies (16.1%), Down syndrome (9.1%), thalassemia/haemophilia (8.8%), and muscle dystrophy/spinal muscular atrophy (8.4%). The disorders for which prenatal has been done over an 18-month-period are given. A recent study carried out in three centers (Mumbai, Delhi and Baroda) on 94,610 newborns by using a uniform proforma showed a malformation frequency of 2.03%, the commonest malformations are neural tube defects and musculo-skeletal disorders. The frequency of Down syndrome among 94,610 births was 0.87 per 1000, or 1 per 1150. Screening of 112,269 newborns for aminoacid disorders showed four disorders to be the commonest--tyrosinemia, maple syrup urine disease and phenylketonuria. Screening of cases of mental retardation for aminoacid disorders revealed four to be the commonest--hyperglycinemia, homocystinuria, alkaptonuria, and maple syrup urine disease. Metabolic studies of cases of mental retardation in AIIMS, Delhi and KEM Hospital, Mumbai, demonstrated that common disorders were those of mucopolysaccharides, lysosomes, Wilson disease, glycogen storage disease and galactosemia. It is estimated that beta- thalassemia has a frequency at birth of 1:2700, which means that about 9,000 cases of thalassemia major are born every year. Almost 5200 infants with sickle cell disease are born every year. Disorders, which deserve to be screened in the newborn period, are hypothyroidism and G-6-PD deficiency, while screening for aminoacid and other metabolic disorders could presently be restricted to symptomatic infants.

Prevalencia del síndrome de down en asturias, 1987-1993

To determine the frequency of Down Syndrome (DS) in Asturias and the prenatal diagnosis impact on the birth prevalence of this chromosomal anomaly. The analysed data came from the Registry of Congenital Defects of Asturias (1990-1993) and from a retrospective study conducted by the same working group (1987-1989). The total prevalence rates and the prevalence at birth were calculated. Out of 55,601 births, DS was recorded in 83 cases: 69 livebirths, two fetal deaths and 12 induced abortions following prenatal diagnosis, giving a total prevalence rate of 14.9 per 10,000 and a birth prevalence of 12.8. The proportion of induced abortions was 15 per cent in this period; the proportion of cases in the high risk maternal age group (35 years and over) was around 50% of the total. The proportion of induced abortions was 15 per cent in this period. The frequency of DS in Asturias is comparable to the other populations. Prenatal diagnosis had little impact on the birth prevalence figures. These results may help us draw up prevention and prenatal diagnosis policies for these defects in Asturias when giving the frequency of this health problem.

PRENATAL DIAGNOSIS AND DOWN SYNDROME: PART 2. POSSIBLE EFFECTS

AbstractThe effects of prenatal diagnosis on the birth frequency of Down syndrome are considered through a review of recent literature. Both present and possible future effects are discussed and brief mention of some psychological aspects of prenatal diagnosis is made. The incomplete uptake of amniocentesis is noted; ranging from 20% to over 40% of eligible women in recent British studies; reasons for this are explored. A consideration of reported changes in age specific incidence and their relationship to the introduction and continued use of prenatal diagnosis is given. Reductions in incidence of between 5% and 18% have been reported in the past. The maximum future effects, as predicted by studies using age in conjunction with biochemical screening methods, are noted; detection of up to 60% of affected foetuses is theoretically possible. However, problems of introducing this type of scheme may prevent such effective screening methods being widely adopted. This being the case, it seems unlikely that more than 15% of births affected by Down syndrome will be prevented by prenatal diagnosis in the foreseeable future.

Cytogenetic analysis of down syndrome in Libya

The frequency of Down syndrome in Libya was 1 in 516 live births. The mean age of Down mother was 35.62 years. Eighty two percent of the Down mothers were over 30 years of age as compared to 36% of the control Libyan mothers. As there was a greater percentage of late conceptions, the maternal age appears to be influential in the birth of Down syndrome in Libya. Cytogenetically 96% of the cases were that of trisomy 21. There was one case each of mosaic and 21/21 translocation, and four cases of 14/21 translocation as evidenced by Giemsa banding. Twenty two percent of the cases of Down syndrome also had other associated congenital abnormalities. The unique features involved in genetic counselling in this population are discussed. This study reflects the enormous problem of Down syndrome in the Arab world.

Down syndrome, water fluoridation, and maternal age.

It has been claimed that there is a positive association between the frequency of Down syndrome and the fluoridation of drinking water. It has also been suggested that this association is most pronounced in young women. Recent congenital malformations data obtained from birth certificates from large U.S. cities have been analyzed. Some cities had fluoridated water supplies, while others had supplies deficient in fluoride. The rates of Down syndrome in the cities with fluoridated and in those with non-fluoridated water supplies were comparable. In addition, there was no indication of any maternal age-specific association.

Frequency of Down syndrome in livebirths by single-year maternal age interval: results of a Massachusetts study.

An analysis of rates of intra-state Down syndrome livebirths to Massachusetts residents by single-year maternal age interval in 1958-1965 inclusive was carried out. A gradual increase of rate of the Down syndrome occurred from age 20 to about age 31, and a steeper increase thereafter. Different regression equations were derived in the 20-31 and the 33-45 age group. The regression equations were ln y = 0.04515 x -1.45759 for those age 20-31 and ln y = 0.24302x-7.57870, for those age 33-45, where y = rate per 1,000 and x = maternal age. The regression-derived rates are slightly lower than those reported in similar analyses of data from Sweden and New York State, but they are not markedly discrepant.