Trisomies 13 and 18: prenatal diagnosis and epidemiologic studies in Hawaii, 1986-1997

Using a birth defects registry, this study examined the influence of prenatal diagnosis and elective termination of pregnancy on trisomy 13 and trisomy 18 prevalence in Hawaii between 1986 and 1997. The investigation also evaluated the impact of various demographic factors on risk for the aneuploidies. Forty-seven cases of trisomy 13 and 116 cases of trisomy 18 were identified. The total prevalence of trisomy 13 was 1.91 per 10,000 births and of trisomy 18 was 4.71 per 10,000 births. Elective terminations accounted for 38.3% of trisomy 13 cases and 48.3% of trisomy 13 cases. The 1-year mortality rate for trisomy 13 was 89.5% and for trisomy 18 was 74.3%. Rates for both aneuploidies increased during the time period. The racial/ethnic group with the highest prevalence of both anomalies was Far East Asian. The aneuploidies were more common in metropolitan Honolulu than the rest of Hawaii. Demographic factors demonstrated differences in risk for trisomies 13 and 18, although most of these differences appeared to be due, at least in part, to differences in maternal age distribution. For the secular trend, increased prenatal diagnosis of the anomalies also contributed to the observed increase.     

Prenatal diagnosis, pregnancy terminations and prevalence of Down syndrome in Atlanta

BACKGROUND: The impact of prenatal diagnosis on the live birth prevalence of Down syndrome (trisomy 21) has been described. This study examines the prevalence of Down syndrome before (1990-1993) and after inclusion of prenatally diagnosed cases (1994-1999) in a population-based registry of birth defects in metropolitan Atlanta. METHODS: We identified infants and spontaneous fetal deaths with Down syndrome (n = 387), and pregnancies electively terminated after a prenatal diagnosis of Down syndrome (n = 139) from 1990 to 1999 among residents of metropolitan Atlanta from a population-based registry of birth defects, the Metropolitan Atlanta Congenital Defects Program (MACDP). Only diagnoses of full trisomy 21 were included. Denominator information on live births was derived from State of Georgia birth certificate data. We compared the prevalence of Down syndrome by calendar period (1990-1993, 1994-1999), maternal age (<35 years, 35+ years), and race/ethnicity (White, Black, other), using chi-square and Fisher's exact tests. RESULTS: During the period when case ascertainment was based only on hospitals (1990-1993), the prevalence of Down syndrome was 8.4 per 10,000 live births when pregnancy terminations were excluded and 8.8 per 10,000 when terminations were included. When case ascertainment also included perinatal offices (1994-1999), the prevalence of Down syndrome was 10.1 per 10,000 when terminations were excluded and 15.3 when terminations were included. During 1990-1993, the prevalence of Down syndrome was 24.7 per 10,000 among offspring to women 35+ years of age compared to 6.8 per 10,000 among offspring to women <35 years of age (rate ratio [RR] = 3.65, 95% confidence interval [CI] = 2.53-5.28). During 1994-1999, the prevalence of Down syndrome was 55.3 per 10,000 among offspring to women 35+ years compared to 8.5 per 10,000 among offspring to women <35 years (RR = 6.55, 95% CI = 5.36-7.99). There was no statistically significant variation in the prevalence of Down syndrome by race/ethnicity within maternal age and period of birth strata. During 1994-1999, the proportion of cases that were electively terminated was greater for women 35+ years compared to women <35 years (RR = 5.10, 95% CI = 3.14-8.28), and lower for Blacks compared to Whites among women 35+ years of age (RR = 0.33, 95% CI = 0.16-0.66). CONCLUSIONS: In recent years, perinatal offices have become an important source of cases of Down syndrome for MACDP, contributing at least 34% of cases among pregnancies in women 35+ years of age. Variation in the prevalence of Down syndrome by race/ethnicity, before or after inclusion of cases ascertained from perinatal offices, was not statistically significant. Among Down syndrome pregnancies in mothers 35+ years we found a lower proportion of elective termination among Black women compared to White women. We suggest that future reports on the prevalence of Down syndrome by race/ethnicity take into account possible variations in the frequency of prenatal diagnosis or elective termination by race/ethnicity.     

National estimates and race/ethnic-specific variation of selected birth defects in the United States, 1999-2001

BACKGROUND: In the United States, birth defects affect approximately 3% of all births, are a leading cause of infant mortality, and contribute substantially to childhood morbidity. METHODS: Population-based data from the National Birth Defects Prevention Network were combined to estimate the prevalence of 21 selected defects for 1999-2001, stratified by surveillance system type. National prevalence was estimated for each defect by pooling data from 11 states with active case-finding, and adjusting for the racial/ethnic distribution of US live births. We also assessed racial/ethnic variation of the selected birth defects. RESULTS: National birth defect prevalence estimates ranged from 0.82 per 10,000 live births for truncus arteriosus to 13.65 per 10,000 live births for Down syndrome. Compared with infants of non-Hispanic (NH) white mothers, infants of NH black mothers had a significantly higher birth prevalence of tetralogy of Fallot, lower limb reduction defects, and trisomy 18, and a significantly lower birth prevalence of cleft palate, cleft lip with or without cleft palate, esophageal atresia/tracheoesophageal fistula, gastroschisis, and Down syndrome. Infants of Hispanic mothers, compared with infants of NH white mothers, had a significantly higher birth prevalence of anencephalus, spina bifida, encephalocele, gastroschisis, and Down syndrome, and a significantly lower birth prevalence of tetralogy of Fallot, hypoplastic left heart syndrome, cleft palate without cleft lip, and esophageal atresia/tracheoesophageal fistula. CONCLUSIONS: This study can be used to evaluate individual state surveillance data, and to help plan for public health care and educational needs. It also provides valuable data on racial/ethnic patterns of selected major birth defects.     

Down syndrome: interaction between culture, demography, and biology in determining the prevalence of a genetic trait

The incidence of Down syndrome (DS) at conception is highly dependent upon the maternal age distribution and age-specific pregnancy rates. Live-birth prevalence of DS reflects these factors and fetal deaths. Since the introduction of prenatal diagnosis in the early 1970s, the role of fetal deaths in the equation has increased. Between 1920 and the early 1980s, DS live-birth prevalence decreased in many populations due to declining fertility rates, particularly among older women. In the late-1970s the trend reversed, as the median age of populations and birth rates among older women steadily increased. This paper illustrates these interactions using data we have analyzed for New York State (NYS) and comparative data obtained from the literature. Between 1983 and 1997 DS live-birth prevalence in NYS remained stable at about 9.9 per 10,000 live births. The number of prenatal tests performed increased by 158%, and the number of DS fetuses detected prenatally more than quadrupled. Fertility rates of women aged 35-49 continued to increase. The proportion of DS cases born to these older mothers increased from 23% in 1985 to 43% in 1997. We estimated that without prenatal diagnosis, DS live-birth prevalence would have been 17.0 per 10,000 live births by 1995. Cultural factors influence demographic trends, birthing technologies, physician practices, and women's decision-making regarding prenatal screening and diagnosis for DS.     

Descriptive epidemiology of anophthalmia and microphthalmia, Hawaii, 1986-2001

BACKGROUND: Population-based epidemiologic data on anophthalmia and microphthalmia in the United States are limited and have come mainly from only a few states. The intent of this study was to report on the epidemiology of these eye defects. METHODS: Cases were derived from a population-based birth defects registry in Hawaii and comprised all infants and fetuses with anophthalmia and microphthalmia who were delivered during 1986-2001. Anophthalmia and microphthalmia rates per 10,000 births were determined for selected factors, and comparisons were made by calculating the rate ratios and 95% confidence intervals (CIs). RESULTS: Ninety-six cases of anophthalmia and microphthalmia were identified, with a rate of 3.21 per 10,000 live births. The eye defects were isolated in 5 cases (5.2%), and 24 cases (25.0%) had confirmed chromosomal abnormalities. The risk of anophthalmia and microphthalmia varied over time and was significantly higher for live-born infants with low birth weights and gestational ages. The anophthalmia and microphthalmia rates also varied by maternal race/ethnicity, sex, and plurality, although these differences were not statistically significant. CONCLUSIONS: Anophthalmia and microphthalmia frequently occurred with other birth defects, and the rate was consistent with that found in the literature. The risk of defects differed significantly with time period, birth weight, and gestational age. The impact of many factors on anophthalmia and microphthalmia in Hawaii was frequently consistent with that reported elsewhere.     

Epidemiology of Down syndrome in South Australia, 1960-89.

During 1960-89 687 Down syndrome live births and 46 Down syndrome pregnancy terminations were identified in South Australia. Ascertainment was estimated to be virtually complete. The sex distribution of Down syndrome live births was found to be statistically different from the non-Down syndrome live-birth sex distribution (P less than .01). Smoothed maternal age-specific incidence was derived using both maternal age calculated to the nearest month and a discontinuous-slope regression model. The incidence of Down syndrome at birth for the study period was estimated to be 1.186 Down syndrome births/1,000 live births. Annual population incidence was shown to be correlated with trends in the maternal age distribution of confinements. If current trends in the maternal age distribution of confinements continue, the population incidence of Down syndrome in South Australia is predicted to exceed 1.5 Down syndrome births/1,000 live births during the 1990-94 quinquennium.     

Prevalence of esophageal atresia among 18 international birth defects surveillance programs

BACKGROUND: The prevalence of esophageal atresia (EA) has been shown to vary across different geographical settings. Investigation of geographical differences may provide an insight into the underlying etiology of EA. METHODS: The study population comprised infants diagnosed with EA during 1998 to 2007 from 18 of the 46 birth defects surveillance programs, members of the International Clearinghouse for Birth Defects Surveillance and Research. Total prevalence per 10,000 births for EA was defined as the total number of cases in live births, stillbirths, and elective termination of pregnancy for fetal anomaly (ETOPFA) divided by the total number of all births in the population. RESULTS: Among the participating programs, a total of 2943 cases of EA were diagnosed with an average prevalence of 2.44 (95% confidence interval [CI], 2.35–2.53) per 10,000 births, ranging between 1.77 and 3.68 per 10,000 births. Of all infants diagnosed with EA, 2761 (93.8%) were live births, 82 (2.8%) stillbirths, 89 (3.0%) ETOPFA, and 11 (0.4%) had unknown outcomes. The majority of cases (2020, 68.6%), had a reported EA with fistula, 749 (25.5%) were without fistula, and 174 (5.9%) were registered with an unspecified code. CONCLUSIONS: On average, EA affected 1 in 4099 births (95% CI, 1 in 3954–4251 births) with prevalence varying across different geographical settings, but relatively consistent over time and comparable between surveillance programs. Findings suggest that differences in the prevalence observed among programs are likely to be attributable to variability in population ethnic compositions or issues in reporting or registration procedures of EA, rather than a real risk occurrence difference. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.     

Maternal cigarette smoking, Down syndrome in live births, and infant race.

Previous studies have suggested that maternal smoking is negatively associated with a Down syndrome live birth. We analyzed the data of the U.S. Perinatal Collaborative Study in a search for racial variation in Down syndrome risk factors. There were 22 cases in 25,346 live births to smoking mothers (4/10,780 blacks, 18/13,320 whites, and 0/1,246 other races) and 42/29,130 live births to nonsmoking mothers (24/14,665 blacks, 14/11,694 whites, and 4/2,771 others). The crude overall rates per 1,000 live births were 0.4 in black smokers and 1.6 in black nonsmokers but 1.4 in white smokers and 1.2 in white non-smokers. Adjusted for maternal age, the summary relative risk for a Down syndrome live birth to a smoking mother was 0.2 in blacks (95% interval 0.1-0.7) but 1.2 in whites (95% interval 0.6-2.5). Stratification on variables associated with socioeconomic status or gestational age at time of entry into the study did not alter the racial difference. A comparison of smokers with those who never smoked revealed essentially the same trends. Among all nonsmokers the ratio of the maternal age-adjusted risks for a Down syndrome live birth in whites compared with blacks was 0.7 (95% interval 0.3-1.3), and among all smokers this ratio was 3.6 (95% interval 1.3-9.9). If the results are not attributable to statistical fluctuation or undetected confounding, then differences in the probability of intrauterine survival of the Down syndrome fetus would appear to be one plausible explanation for the difference.     

Down syndrome rates and relaxed selection at older maternal ages.

Preferential survival in older mothers of fetuses with Down syndrome has been proposed as contributing to the maternal-age effect of this condition. If correct, this provocative hypothesis, which may be termed "relaxed selection," has major implications for approaches to prevention of Down syndrome live births in older women. Several predictions of this hypothesis are examined here by comparisons of parental ages among various populations. These revealed that: (1) mean maternal age of Down syndrome live births is slightly lower than that of Down syndrome spontaneous fetal deaths; (2) mean maternal age of those with mutant D/21 translocation Down syndrome is about the same as that of controls; (3) the ages of Down syndrome mothers who have Down syndrome live births is slightly lower than ages of Down syndrome mothers who have unaffected live births; and (4) in recent data on 47, +21 cases in which the extra chromosome 21 is of paternal origin, the mean maternal ages are 4-5 years lower than the maternal ages of cases of maternal origin (in contrast to earlier reports). All of these observations are contrary to the hypothesis that relaxed selection contributes significantly to the maternal-age association of Down syndrome. If there is any effect of relaxed selection, it is likely to be very weak and/or act primarily upon abortions that occur before recognition of pregnancy.     

Prevalence of down syndrome among children and adolescents in metropolitan Atlanta

BACKGROUND: Down syndrome (DS) prevalence estimates beyond infancy are needed to assess health service needs among those with DS. METHODS: Children with DS born in metropolitan Atlanta from 1979 through 2003 were ascertained from a population-based birth defects registry. Vital status through 2003 was obtained using case records, vital records, and the National Death Index. Prevalence was calculated by dividing the children surviving with DS by the population derived from U.S. Census estimates. Variations in DS prevalence by race, heart defects, age, birth cohort, and time period were examined using Poisson regression. RESULTS: In metropolitan Atlanta in 2003, there were 67 livebirths with DS (13.0 per 10,000 livebirths) and 738 0- to 19-year-olds surviving with DS (8.3 per 10,000 population). Over time, births to mothers 35 years and older and DS birth prevalence increased. Birth prevalence was higher among Whites, did not vary by sex, and was higher for infants without heart defects. DS prevalence among 0- to 14-year-olds increased over time (p < .05). Within each 5 year birth cohort, prevalence decreased with age: this decrease was greater among Blacks than among Whites and among children with heart defects than among children without heart defects. CONCLUSIONS: DS prevalence increased among livebirths and among young children. Further studies are warranted to determine whether health services are meeting the needs of an increasing number of children with DS.     

Chromosome abnormalities and spontaneous fetal death following amniocentesis: Further data and associations with maternal age

The pooled results are presented of two North American surveys concerning spontaneous fetal deaths of conceptuses with cytogenetic abnormalities diagnosed prenatally whose mothers had declined elective abortion. The rate of fetal death of those with nonmosaic genotypes associated with Down syndrome was 30.1% (95% confidence interval of 19.0%–42.0%), which is almost identical with the difference of 30% previously estimated between rates observed at amniocentesis and in live births. The fetal death rate for (nonmosaic) 47,+18 was 68.0% (95% confidence interval of 46.5%–85.1%), close to the estimated difference of 75% between rates at amniocentesis and in live births for this genotype. For other nonmosaic genotypes, the rates (and 95% confidence intervals) were: 47,+13, 42.9% (9.9%–81.6%); 47,XXX, 0% (0%–9.0%); 47,XXY, 8.1% (0.8%–11.0%); 47,XYY, 3.0% (.08%–15.8%); for balanced translocations and inversions, 2.8% (0.3%–9.8%); and for markers, variants, and fragments, 0% (0%–12.8%). For 45,X, the rate was 75.0% (42.8%–94.5%), in contrast to the rate for 46,XX/45,X of 10.5% (1.3%–33.1%) and for structural X abnormalities associated with Turner syndrome of 0% (0%–60.2%). The rate for nonmosaic 45,X is significantly different from that for either of the other two categories associated with Turner syndrome. The maternal age of nonmosaic 47,+21 fetuses that survived to live birth was 39.1 ± 6.2, not significantly different from the rate for fetal deaths: 39.5 ± 3.8. The observations provide no support for opposing hypotheses by other groups that maternal age is positively or negatively associated with fetal death of 47,+21 conceptuses. For other chromosome abnormalities, maternal ages of fetal deaths are slightly lower than for live births, but none of the differences are significant. The rates of spontaneous fetal deaths derived here are likely to be pertinent to genetic counseling. Their use in adjusting the rates of abnormalities diagnosed at amniocentesis will enable derivation of predicted contemporary live-birth prevalence rates of abnormalities that would be observed in absence of selective abortion.     

An analysis for temporal variation in Down syndrome births in Ohio, 1970–1979

Our study investigates the epidemiology of Down syndrome (DS) in the state of Ohio during the 1970s. The occurrence of DS births was examined to learn if statistically significant temporal variation was present among these data. Both monthly and annual numbers of DS births, adjusted for changing numbers of live births, were tested for such variation; furthermore, the data were analyzed for cyclic variation by attempting to fit simple trigonometric functions to the data.

Individuals with DS were ascertained using the records of cytogenetics laboratories and birth certificate records. Demographic data such as race, date of birth, and maternal age were collected on these individuals using their birth certificates as the data source. Appropriate parallel live-birth data were obtained from the Ohio Department of Health. The total number of affected individuals ascertained was 1,364, 66.7% of the total estimated population size. The data analysis was restricted to whites only (1,203 individuals) because they represented a more homogeneous sample than the total.

Monthly and annual variation in the numbers of live births was removed by producing single-year maternal-age adjusted numbers of DS births using the total Ohio white live births as the reference population. Analysis of covariance using single-year maternal ages ≤ 16 and ≥ 45 as the covariate was used to analyze the adjusted numbers of DS births for temporal variation.

No significant differences were detected among the annual adjusted numbers of DS births (P = .24), nor were there differences among the monthly adjusted numbers of DS (P = .37). The modes of ascertainment were tested to learn if there were annual or monthly differences in the method of ascertainment. No significant differences were detected for these data (P = .82 and P = .85, respectively). Furthermore, the data were separated into the maternal-age categories < 35 and ≥ 35, and annual and monthly adjusted DS births to these two maternal-age categories were examined for temporal variation. No significant differences were found among these data, P > .10 for all four of the tests. No simple cyclic functions were found to fit either the annual or monthly data.

The Ohio study reported here showed that through the use of a large sample, controlling for variation in the numbers of live births, and the use of detailed statistical tests, no significant temporal variation in the occurrence of DS births existed during the 1970s.

     

Birth defects prevalence among infants of Persian Gulf War veterans born in Hawaii, 1989-1993

BACKGROUND: Gulf War veterans (GWVs) have expressed concern about possible teratogenic exposures. However, epidemiologic studies on birth defects prevalence among their progeny have been limited to military hospitals, anomalies diagnosed among newborns, or self-reported data. To measure the prevalence of selected birth defects among infants of GWVs and nondeployed veterans (NDVs) in Hawaii, using birth defects surveillance records. METHODS: Personal identifiers of 684,645 GWVs and 1,587,102 NDVs and their families were matched against birth certificate records of 99,545 live births reported to the State of Hawaii Department of Health between 1989 and 1993 to identify births to military personnel. These births were matched with records from the Hawaii Birth Defects Program. RESULTS: A total of 17,182 military infants (3,717 GWV infants and 13,465 NDV infants) were identified. Of these, 367 infants (2.14/100 live births) were identified with one or more of 48 major birth defects diagnoses. The prevalence of the 48 birth defects were similar for GWV and NDV infants during the prewar and postwar periods, and among GWV infants who were conceived before and after the Gulf war. CONCLUSIONS: The results must be interpreted with caution because of the small number of affected infants in each birth defects category. This study demonstrated the feasibility of measuring birth defects prevalence among military infants through multiple data linkage. Further, it included live births to parents who had separated from the military, births in civilian hospitals, and birth defects diagnosed through the first year of life.     

Hirschsprung's disease prevalence in Europe: A register based study

Background: Hirschsprung's disease is a congenital gut motility disorder, characterised by the absence of the enteric ganglion cells along the distal gut. The aim of this study was to describe the epidemiology of Hirschsprung's disease, including additional congenital anomalies, total prevalence, trends, and association with maternal age. Methods: Cases of Hirschsprung's disease delivered during 1980 to 2009 notified to 31 European Surveillance of Congenital Anomaly registers formed the population‐based case‐series. Prevalence rates and 95% confidence intervals were calculated as the number of cases per 10,000 births. Multilevel Poisson regression was performed to investigate trends in prevalence, geographical variation and the association with maternal age. Results: There were 1,322 cases of Hirschsprung's disease among 12,146,210 births. The total prevalence was 1.09 (95% confidence interval, 1.03–1.15) per 10,000 births and there was a small but significant increase in prevalence over time (relative risk = 1.01; 95% credible interval, 1.00–1.02; p = 0.004). There was evidence of geographical heterogeneity in prevalence (p < 0.001). Excluding 146 (11.0%) cases with chromosomal anomalies or genetic syndromes, there were 1,176 cases (prevalence = 0.97; 95% confidence interval, 0.91–1.03 per 10,000 births), of which 137 (11.6%) had major structural anomalies. There was no evidence of a significant increased risk of Hirschsprung's disease in cases born to women aged ≥35 years compared with those aged 25 to 29 (relative risk = 1.09; 95% credible interval, 0.91–1.31; p = 0.355). Conclusion: This large population‐based study found evidence of a small increasing trend in Hirschsprung's disease and differences in prevalence by geographic location. There was also no evidence of an association with maternal age. Birth Defects Research (Part A), 100:695–702, 2014. © 2014 Wiley Periodicals, Inc.     

Estimates of Incidence and Prevalence of Mongolism and of Congenital Heart Disease in British Columbia

There is a need for accurate ascertainment of incidence and prevalence rates of congenital anomalies. In British Columbia the Registry for Handicapped Children and Adults used in conjunction with vital records has proved a valuable source of information. Birth notifications alone cannot be relied upon for incidence data. It was found that seven times as many cases of congenital heart disease were registered subsequently as were reported at birth. The estimated minimal incidence rates of mongolism and congenital heart disease per 1000 live births were 1.46 and 4.75, respectively. The well-known association of maternal age with mongolism was confirmed. Twice as many babies with congenital heart disease (without mongolism) were born to mothers over 39 years of age as would be expected on the basis of the maternal age distribution for all live births in the population. Prevalence estimates of these two diseases compared favourably with other published estimates.     

The frequency of lysosomal storage diseases in The Netherlands

We have calculated the relative frequency and the birth prevalence of lysosomal storage diseases (LSDs) in The Netherlands based on all 963 enzymatically confirmed cases diagnosed during the period 1970–1996. The combined birth prevalence for all LSDs is 14 per 100,000 live births. Glycogenosis type II is the most frequent LSD with a birth prevalence of 2.0 per 100,000 live births, representing 17% of all diagnosed cases. Within the group of lipidoses, metachromatic leukodystrophy (MLD) is the most frequent LSD. MLD was diagnosed in 24% of lipidoses and the calculated birth prevalence was 1.42 per 100,000 for all types combined. Krabbe disease, diagnosed in 17% of cases, also belongs to the more frequent lipid storage diseases in The Netherlands with a birth prevalence of 1.35 per 100,000. The birth prevalence of Gaucher disease, commonly regarded as the most frequent lipid storage disease is 1.16 per 100,000 for all types combined. The combined birth prevalence for all lipid storage diseases is 6.2 per 100,000 live births. Within the group of mucopolysaccharidoses (MPSs), MPS I has the highest calculated birth prevalence of 1.19 per 100,000 (25% of all cases of MPS diagnosed), which is slightly more frequent than MPS IIIA with an estimated birth prevalence of 1.16 per 100,000. As a group, MPS III comprises 47% of all MPS cases diagnosed and the combined birth prevalence is 1.89 per 100,000 live births. The birth prevalence of MPS II is 0.67 per 100,000 (1.30 per 100,000 male live births). All other MPSs are rare. The combined birth prevalence for all MPSs is 4.5 per 100,000 live births. Mucolipidoses and oligosaccharidoses are very rare with birth prevalences between 0.04 and 0.20 for individual diseases. Only 49 cases were diagnosed between 1970 and 1996. Their combined birth prevalence is 1.0 per 100,000 live births.     

Secular trends of demographic parameters

The aim of this paper is to describe the secular changes of selected demographic parameters and to investigate the possible causes for such changes as well as the biological relevance. We took into account the following parameters: population density, mean live expectancy, average age at marriage of until then unmarried persons, rate of live births, and number of children per woman. The results show that the population density (global and in Germany) especially in the twentieth century increased dramatically. We found a striking increase of life expectancy in Germany. Essential causes are rapid decreases in infant and maternal mortality. Since the 80s of the twentieth century the average age at marriage of until then unmarried persons as well as the number of single mothers show a permanent increase. Generally, the average age of mothers increased (for live and legitimate births). In the past 150 years we found a decrease in fertility rates in Germany. The registered demographic parameters show temporal and regional variations. These differences, especially between East Germany and West Germany, are emphasized.     

Descriptive epidemiology of lipomyelomeningocele, Hawaii, 1986-2001

BACKGROUND: The epidemiology of neural tube defects (NTDs) may depend on the type of the defect and its location. There is little epidemiologic information on lipomyelomeningocele, a type of NTD. The objective of this investigation was to describe the epidemiology of lipomyelomeningocele. METHODS: Cases were obtained from a Hawaii birth defect registry and consisted of all infants delivered during 1986-2001 with lipomyelomeningocele. Lipomyelomeningocele rates per 10,000 births were calculated for various factors. RESULTS: A total of 17 cases of lipomyelomeningocele were identified, for a total rate of 0.57. When the lipomyelomeningocele rate was examined with respect to the time period of folic acid fortification of cereal grains in the United States, the rate was 0.57 during 1986-1996 (prefortification), 0.57 during 1997-1998 (voluntary fortification), and 0.58 during 1999-2001 (mandatory fortification). A total of 11 (64.7%) of the cases were female. Lipomyelomeningocele rates were higher among infants born to mothers in younger and older age groups. The rate was highest among Pacific Islanders, followed by Filipinos and Far East Asians, and lowest among whites. Rates were greater with lower birth weight and gestational age and among multiple births. CONCLUSIONS: Lipomyelomeningocele rates were not found to be affected by folic acid fortification. The majority of cases were female. Other demographic and clinical factors appear to be associated with lipomyelomeningocele risk. None of the differences in rates between the various subgroups were statistically significant, and due to the small number of cases, the 95% confidence interval (CI) ranges were wide. However, the findings suggest possible patterns of occurrence. Additional studies involving larger numbers of cases are recommended.