Anal atresia, vertebral, genital, and urinary tract anomalies: a primary polytopic developmental field defect identified through an epidemiological analysis of associations

Anal atresia (AA) is observed per se or as part of different Mendelian or chromosomal syndromes, and as part of the VACTERL primary developmental field, CHARGE association, cloacal extrophy, in a mitochondrial cytopathy, and other multiple congenital anomaly patterns. There are only a few studies on the defects associated with AA, and in all of them it was observed that genitourinary defects are most frequent in infants with AA. Here we present the analysis of 28,410 malformed infants to study the frequency of 11 selected congenital defects in infants with AA in relation to their frequency in infants with multiple congenital anomaly patterns without AA. We conclude that the association of AA + spine defects + renal/urinary tract defects + genital defects constitutes a group of defects that tends to be present together in the same child because they are pathogenetically related, and since they are of blastogenetic origin they constitute a primary polytopic developmental field defect.     

Limb defects associated with major congenital anomalies: clinical and epidemiological study from the International Clearinghouse for Birth Defects Monitoring Systems

Although limb defects associated with other congenital anomalies are rarely studied, they may provide insights into limb development that may be useful for etiologic studies and public health monitoring. We pooled data from 11 birth defect registries that are part of the International Clearinghouse for Birth Defects Monitoring Systems. We identified 666 infants, born from 1983 through 1993, who had a non-syndromal limb defect plus at least one other major malformation (rate 12.9/100,000 population). We used observed/expected ratios and log-linear models to detect association patterns. We found that specific limb defects occurred with relatively distinct sets of malformations. Preaxial limb defects occurred more frequently with microtia, esophageal atresia, anorectal atresia, heart defects, unilateral kidney dysgenesis, and some axial skeleton defects; postaxial defects with hypospadias; transverse defects with craniofacial defects, micrognathia, ring constrictions, and muscular defects; intercalary defects with omphalocele; split hand/foot with encephalocele; and amelia with anorectal atresia, omphalocele, severe genitalia defects, unilateral kidney dysgenesis, gastroschisis, and ring constriction. Log-linear modeling identified higher order associations among some of these same malformations.     

VACTERL association,epidemiologic definition and delineation

This study departed from a preconceived definition of VACTERL, including more than one of these six anomalies in the same infant:; V (vertebral anomalies), A (anal atresia), C (congenital heart disease), TE (tracheoesophageal fistula or esophageal atresia), R (reno-urinary anomalies), and L (radial limb defect). Under this definition, 524 infants were ascertained by ECLAMC from almost 3,000,000 births examined from 1967 through 1990. Observed association rates among VACTERL components as well as between VACTERL and other defects were compared against randomly expected values obtained from 10,084 multiply malformed infants (casuistic method) from the same birth sample. Conclusions were: 1) Cardiac defects are not a part of VACTERL. 2) Single umbilical artery, ambiguous genitalia, abdominal wall defects, diaphragmatic hernia, and anomalies that are secondary to VACTERL components (intestinal and respiratory anomalies, and oligohydramnios sequence defects) are frequent enough to be considered an “extension” of VACTERL, and cardiac defects should be included in this category. 3) Neural tube defects are negatively associated with VACTERL which could not be explained by selection bias or any other operational artifact. High embryonic lethality or mutually exclusive pathogenetic mechanisms could be suitable explanations. 4) Results were not clear enough to determine whether VACTERL should be defined by at least two or three component defects. © 1996 Wiley-Liss, Inc.     

Associated anomalies in multi-malformed infants with cleft lip and palate: An epidemiologic study of nearly 6 million births in 23 EUROCAT registries

We studied 5,449 cases of cleft lip (CL) with or without cleft palate (CL/P) identified between 1980 and 2000 from the EUROCAT network of 23 registers (nearly 6 million births) in 14 European countries. We investigated specific types of defects associated with clefts. Among CL/P cases (prevalence = 9.1 per 10,000), 1,996 (36.6%) affected only the lip (CL) and 3,453 (63.4%) involved CL and palate (CLP). A total of 3,860 CL/P cases (70.8%) occurred as isolated anomalies and 1,589 (29.2%) were associated with other defects such as multiple congenital anomalies of unknown origin (970), chromosomal (455) and recognized syndromes (164). Associated malformations were more frequent in infants who had CLP (34.0%) than in infants with CL only (20.8%). Among multi-malformed infants, 2 unrelated anomalies were found in 351 cases, 3 in 242 cases, and 4 or more in 377 cases. Among 5,449 CL/P cases, 4,719 were live births (LB) (86.6%), 203 stillbirths (SB) (3.7%), while 508 (9.3%) were terminations of pregnancy (ToP). CL/P occurred significantly more frequently in males (M/F = 1.70), especially among total isolated cases (M/F = 1.87) and CLP isolated cases (M/F = 1.92). The study confirmed that musculoskeletal, cardiovascular, and central nervous system defects are frequently associated with CL/P. An association with reduction anomalies of the brain was found. This association suggests that clinicians should seek to identify structural brain anomalies in these patients with CL/P as the potential functional consequences may be important for rehabilitation and clinical management.     

Congenital defects of the limbs in stillbirths: Data from a population-based study

We analyzed limb deficiencies occurring in stillbirths with congenital anomalies registered in the Health Surveillance Registry of British Columbia between the years 1964 and 1984. Thirty stillborn infants presenting with various defects of the limbs were found during this time, giving an incidence of 39.52 in 10,000 stillbirth (1:253). This incidence is significantly higher than the incidence among liveborn individuals in the Province (5.97 in 10,000 livebirths or 1:1,842). Most cases involved the upper limbs, and most frequently the radius. Additional anomalies were present in 77% of cases, compared to 48% in liveborns. The study of stillbirth with congenital anomalies provides important information regarding the spectrum of birth defects seen in this group. This may be of relevance because of improved survival possibilities due to advances in perinatal care. © 1993 Wiley-Liss., Inc. © 1993 Wiley-Liss, Inc.     

Anorectal anomalies associated with or as part of other anomalies

Anorectal anomalies occurring with other anomalies or as part of syndromes were analyzed to determine how their epidemiological characteristics differed from those of isolated anal anomalies. Almost 15% of cases were chromosomal, monogenic or teratogenic syndromes, whereas the rest were of unknown cause including sequences (9.3%), VACTERL associations (15.4%) and multiple congenital anomalies (MCA) (60.2%). Almost half of babies with MCA had one or two VACTERL anomalies with distribution frequencies that did not differ significantly from those in babies with the full VACTERL association. There were considerable differences in the frequency of the VACTERL association among babies with different types of anorectal anomaly. Babies with anal anomalies occurring with sequences, VACTERL or MCA showed the same sex differences as babies with isolated anal anomalies, namely male predominance in anal atresia without fistula or cloaca, no sex difference in anal atresia with fistula, and female predominance in ectopic anus and congenital anal fistula. These anomalies, however, were associated with significantly lower mean gestational lengths and birth weights, and higher frequencies of fetal death and pregnancy termination than babies with isolated anal anomalies. Twins were more frequent in sequences, VACTERL and MCA than in isolated anomalies, monogenic syndromes or chromosome anomalies. Five cases were conjoined twins, representing 15% of all cases of twin pregnancies with an anal anomaly. Indeterminate sex was more frequent in babies with anal atresias without fistula than in those with fistula. Anal anomalies are defects of blastogenesis attributable to disorders in expression of pattern determining genes. The differential sex involvement in different types of anal anomaly may be manifestations of expression of the HY/SRY genes during blastogenesis or of X-linkage.     

Tracheal agenesis and associated malformations: a comparison with tracheoesophageal fistula and the VACTERL association

Tracheal agenesis is a rare malformation of the lower respiratory tract. Investigation of a patient with multiple congenital anomalies and tracheal agenesis prompted a review of the literature which uncovered 42 previously published cases, most of whom had other defects. The presence in our patient of a tracheal abnormality in association with radial hypoplasia, single umbilical artery, tetralogy of Fallot, and left hydroureter initially suggested presence of the VACTERL association. However, numerical classification of malformation patterns in the reported patients with tracheal agenesis and in a series of patients with tracheoesophageal fistula and other components of the VACTERL association suggests that tracheal agenesis does not occur in the VACTERL association and may be part of another pattern of malformations which includes laryngeal atresia, complex congenital heart anomalies, radial ray defects, and duodenal atresia.     

Analysis of deformations in 26,810 consecutive infants with congenital defects.

Here we present the analysis of deformations observed in a series of 26,810 consecutive infants with congenital defects. We observed that 3.88% of these infants had deformations, for a prevalence figure of 0.07% live-born infants. From the present study we can conclude that there are three different types of deformation sequences: one with polyhydramnios, thin skin without dermal ridges, hypotonia, and multiple deformations (hypokinesia sequence), which is most often due to intrinsic problems; another with oligohydramnios, redundant thick skin, and multiple deformations, which can be produced by intrinsic or extrinsic factors; and the third, with normal amniotic fluid volume, which is due to compression of different causes. Deformations of extrinsic cause are more frequently isolated defects and have a better prognosis, while deformations of intrinsic origin are more frequently associated with other congenital anomalies and, generally, have a poor prognosis.     

Anencephaly and limb deficiencies.

Limb deficiencies (LDs) are rarely reported in anencephalic infants. A review of 662 patients in the literature on non-neural defects in anencephaly only showed five patients with LDs. We report on eight patients with various LDs from the records of 141 necropsies of the anencephalic infants found among 495,830 births. Compared with another group of anencephalic infants reported in the literature, the patients in this group of anencephalic infants with LDs were predominantly male, their mean gestational age was younger by approximately 5 weeks, their mean birth-weight was approximately 1,400 g less, and they presented with a higher incidence of polyhydramnios during gestational development. The association of this pair of anomalies, which was 100 times more frequent than expected, seems not due to chance. Since all eight patients had other multiple congenital anomalies (MCA), in addition to anencephaly and LDs, the postmortem study should be mandatory in anencephalic infants with LDs. The most common associated anomalies were cardiovascular and renal defects. Oral clefts, diaphragmatic hernia, esophageal atresia, and imperforate anus were also observed in these infants. The recognition of LDs in anencephalic infants indicates severe and extensive disturbance of the early embryogenesis (blastogenesis), which affects the midline of the embryo.     

Epidemiological association between isolated skin marks in newborn infants and single umbilical artery (SUA). Does it have biological plausibility?

In a previous study on single umbilical artery (SUA) and its association with congenital defects, we observed a serendipitous association between isolated skin anomalies and the presence of SUA. Although this could be a spurious association, we considered that it deserved to be studied in detail. The aim of this study was to investigate, in an epidemiological setting, whether this association has any biological meaning or if it occurs just by chance. Using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), we analyzed "angiomas" (including all type of capillary skin marks, since it is not possible to distinguish it during the first 3 days of life), and nevi because they are the only defects detected in newborn infants as isolated skin defects. In the ECEMC methodology, infants with nevi or angiomas as the only congenital defect are considered as cases when they present with only one of these skin marks measuring at least 1 cm in diameter and within the first 3 days of life, or when they have three or more such marks of any size. A total sample of 1,832 consecutive newborn infants with isolated congenital skin marks was identified: 871 with nevi, 958 with angiomas, and 3 with both. Newborn infants with SUA and isolated angiomas displayed higher birth measurements, and older maternal and paternal ages than newborn infants with angiomas and three umbilical vessels. Similar results were observed when infants with angiomas and SUA were compared with control infants either with or without SUA. These associations were not observed in newborn infants with nevi with or without SUA or for control infants with or without SUA. The distribution of the angiomas by body areas, and sex preferences were also analyzed. After evaluating the limitations and advantages of the present study, the results suggest that newborn infants with angiomas (irrespective of their type), SUA, and higher centile measurements may have one of the syndromes that exhibit this type of skin mark. Although this observation requires confirmation, we do suggest close attention to newborns with these three signs.     

Anencephaly and limb deficiencies

Limb deficiencies (LDs) are rarely reported in anencephalic infants. A review of 662 patients in the literature on non-neural defects in an-encephaly only showed five patients with LDs. We report on eight patients with various LDs from the records of 141 necropsies of the anencephalic infants found among 495,830 births. Compared with another group of anencephalic infants reported in the literature, the patients in this group of anencephalic infants with LDs were predominantly male, their mean gestational age was younger by approximately 5 weeks, their mean birth-weight was approximately 1,400 g less, and they presented with a higher incidence of polyhydramnios during gestational development. The association of this pair of anomalies, which was 100 times more frequent than expected, seems not due to chance. Since all eight patients had other multiple congenital anomalies (MCA), in addition to anencephaly and LDs, the postmortem study should be mandatory in anencephalic infants with LDs. The most common associated anomalies were cardiovascular and renal defects. Oral clefts, diaphragmatic hernia, esophageal atresia, and imperforate anus were also observed in these infants. The recognition of LDs in anen-cephalic infants indicates severe and extensive disturbance of the early embryogenesis (blastogenesis), which affects the midline of the embryo. © 1992 Wiley-Liss, Inc.     

Midline congenital anomalies: the estimated occurrence among American Indian and Alaska Native infants

While congenital anomalies have been identified as the second leading cause of infant mortality among American Indians and Alaska Natives, limited information exists concerning the morbidity of such malformations. This study was undertaken to address this concern. Using data from the national hospital discharge database of the Indian Health Service, for the years 1980–1988, morbidity rates of seven, relatively common and easily identifiable midline malformations among liveborn infants in this minority population were estimated. The seven congenital anomalies and the estimated rates per 10000 births were: neural tube defects 8.09; oral clefts 29.03; abdominal wall defects 2.99; tracheoesophageal fistula 1.86; conotruncal heart defects 5.90; rectal atresia 3.15; and diaphragmatic hernia 3.24. Seven cases (1.1%) had two midline defects reported.     

Analysis of deformations in 26,810 consecutive infants with congenital defects

Here we present the analysis of deformations observed in a series of 26,810 consecutive infants with congenital defects. We observed that 3.88% of these infants had deformations, for a prevalence figure of 0.07% live-born infants. From the present study we can conclude that there are three different types of deformation sequences: one with polyhydramnios, thin skin without dermal ridges, hypotonia, and multiple deformations (hypokinesia sequence), which is most often due to intrinsic problems; another with oligohydramnios, redundant thick skin, and multiple deformations, which can be produced by intrinsic or extrinsic factors; and the third, with normal amniotic fluid volume, which is due to compression of different causes. Deformations of extrinsic cause are more frequently isolated defects and have a better prognosis, while deformations of intrinsic origin are more frequently associated with other congenital anomalies and, generally, have a poor prognosis. Am. J. Med. Genet. 84:365–368, 1999. © 1999 Wiley-Liss, Inc.     

Using log-linear models to test for associations among congenital malformations

Log-linear models can be used to test for pairwise associations and higher order interactions among anatomically distinct birth defects or congenital malformations. A log-linear model, including terms for every possible pairwise association among seven severe and easily detectable congenital malformations, was examined using data on 16,217 infants registered in the Metropolitan Atlanta Congenital Defects Program between 1968 and 1986. The resulting model showed clear patterns of strong association between some congenital malformations and not others, and the presence of 3-way interaction terms where the association between two malformations depended on the presence of a third. Examining a more parsimonious log-linear model showed overlapping patterns of pairwise association involving anal-rectal atresia and omphalocele, anal-rectal atresia and limb deficiency, and anal-rectal atresia and tracheaesophageal fistula. A second common pattern involved a triangular cluster with a hierarchical relationship among the three malformations (where there was a strong association between the first and second malformations and between the first and third malformations, but the association between the second and third was only seen in the absence of the first). Three such overlapping triangular clusters were identified from these data: neural tube defects, oral clefts, and omphalocele; neural tube defects, oral clefts, and limb deficiency; and limb deficiency, diaphragmatic hernia, and neural tube defects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of Birth Defects in Korean Livebirths, 2005-2006

We investigated the livebirths prevalence and occurrence pattern of birth defects in Korea. After the survey on birth defects was done in 2,348 medical institutions around the nation, the birth defect prevalence of livebirths in 2005-2006 was calculated. This study was based on the medical insurance claims database of the National Health Insurance Corporation. The number of livebirths in Korea was 883,184 from 2005-2006, and 25,335 cases of birth defects were notified to our study, equivalent to a prevalence of 286.9 per 10,000 livebirths. Anomalies of the circulatory system were the most common defects, accounting for 43.4% of birth defects with a prevalence of 124.5 per 10,000 livebirths. It was followed by the musculoskeletal system anomalies, the digestive system anomalies, and the urinary system anomalies. The five major birth defects based on the ranking of prevalence were atrial septal defect, ventricular septal defect, hydronephrosis, patent ductus arteriosus, and cleft lip/palate. Birth defects in livebirths were associated with a high proportion of low birthweight, prematurity, multiple births and advanced maternal age. The prevalence of birth defects in Korea is similar to or lower than those reported in developed countries. Our study suggests baseline data to explain the current status of birth defects and to establish a registry system of birth defects in Korea.     

Associated nonurinary congenital anomalies among infants with congenital anomalies of kidney and urinary tract (CAKUT)

Infants with congenital anomalies of kidney and urinary tract (CAKUT) often have other associated anomalies. The purpose of this investigation was to assess the prevalence and the types of associated anomalies in CAKUT in a defined population from northeastern France. The associated anomalies in CAKUT were collected in all livebirths, stillbirths and terminations of pregnancy during 26 years in 346,831 consecutive births of known outcome in the area covered by our population based registry of congenital anomalies. Of the 1678 infants with CAKUT born during this period (prevalence at birth of 48.4 per 10,000), 563 (34%) had associated anomalies. There were 119 (7%) patients with chromosomal abnormalities including 33 trisomies 18 (2%), and 168 (10%) nonchromosomal recognized dysmorphic conditions. There were no predominant recognized dysmorphic conditions, but VA(C)TER(L) association (3%). However, other recognised dysmorphic conditions were registered including Meckel–Gruber syndrome (2%), and prune belly syndrome (1%). Two hundred seventy six (16%) of the patients had multiple congenital anomalies, non syndromic, non chromosomal (MCA). Anomalies in the musculoskeletal, the digestive, the cardiovascular and the central nervous systems were the most common other anomalies. Prenatal diagnosis was obtained in 71% of dysmorphic syndromes with CAKUT. In conclusion the overall prevalence of associated anomalies, which was one in three infants, emphasizes the need for a thorough investigation of infants with CAKUT. The most commonly associated major nonurinary anomalies involved the musculoskeletal system, followed by the digestive, the cardiovascular and the central nervous systems. A routine screening for other anomalies may be considered in infants and in fetuses with CAKUT. One should be aware that the anomalies associated with CAKUT can be classified into a recognizable anomaly syndrome or pattern in one out of six infants with CAKUT.     

Environmental and Genetic Risk Factors of Congenital Anomalies: an Umbrella Review of Systematic Reviews and Meta-Analyses

BackgroundThe prevalence of congenital anomalies in newborns in South Korea was 272.9 per 100,000 in 2005, and 314.7 per 100,000 in 2006. In other studies, the prevalence of congenital anomalies in South Korea was equivalent to 286.9 per 10,000 livebirths in 2006, while it was estimated 446.3 per 10,000 births during the period from 2008 to 2014. Several systematic reviews and meta-analyses analyzing the factors contributing to congenital anomalies have been reported, but comprehensive umbrella reviews are lacking.MethodsWe searched PubMed, Google Scholar, Cochrane, and EMBASE databases up to July 1, 2019, for systematic reviews and meta-analyses that investigated the effects of environmental and genetic factors on any type of congenital anomalies. We categorized 8 subgroups of congenital anomalies classified according to the 10th revision of the International Statistical Classification of Diseases (ICD-10). Two researchers independently searched the literature, retrieved the data, and evaluated the quality of each study.ResultsWe reviewed 66 systematic reviews and meta-analyses that investigated the association between non-genetic or genetic risk factors and congenital anomalies. Overall, 269 associations and 128 associations were considered for environmental and genetic risk factors, respectively. Congenital anomalies based on congenital heart diseases, cleft lip and palate, and others were associated with environmental risk factors based on maternal exposure to environmental exposures (air pollution, toxic chemicals), parental smoking, maternal history (infectious diseases during pregnancy, pregestational and gestational diabetes mellitus, and gestational diabetes mellitus), maternal obesity, maternal drug intake, pregnancy through artificial reproductive technologies, and socioeconomic factors. The association of maternal alcohol or coffee consumption with congenital anomalies was not significant, and maternal folic acid supplementation had a preventive effect on congenital heart defects. Genes or genetic loci associated with congenital anomalies included MTHFR, MTRR and MTR, GATA4, NKX2-5, SRD5A2, CFTR, and 1p22 and 20q12 anomalies.ConclusionThis study provides a wide perspective on the distribution of environmental and genetic risk factors of congenital anomalies, thus suggesting future studies and providing health policy implications.     

Fryns syndrome: report on 8 new cases

The name Fryns syndrome was given to a new variable multiple congenital anomaly syndrome, almost always lethal, described in 1978, and now known to be autosomal recessive. Since that date, 20 patients have been reported in the literature. We describe 8 new cases, 6 of which were diagnosed in a series of 112,276 consecutive births (livebirths and perinatal deaths). The prevalence of this syndrome can be estimated to be around 0.7 per 10,000 births. These new cases confirm that the most frequent anomalies are diaphragmatic defects, lung hypoplasia, cleft lip and palate (often bilateral), cardiac defects (septal defects and aortic arch anomalies), renal cysts (type II, III or IV), urinary tract malformations, and distal limb hypoplasia. Most patients also have hypoplastic external genitalia and anomalies of internal genitalia (bifid or hypoplastic uterus, immature testes). The digestive tract is also often abnormal: duodenal atresia, pyloric hyperplasia, malrotation and common mesentery are present in half of the patients. When the brain was examined, more than half were abnormal (Dandy-Walker anomaly and agenesis of corpus callosum). A few patients demonstrated cloudy cornea. We examined the eyes of three patients histologically: two of them showed retinal dysplasia with rosettes and gliosis of the retina, thickness of posterior capsula of lens and irregularities of the Bowman membrane. Four of our cases were diagnosed prenatally between 24 and 27 weeks. It is to be expected that prenatal diagnosis will be made often and earlier in the future, as the spectrum of anomalies of the Fryns syndrome can easily be evidenced by sonography.     

Genetic diagnoses and associated anomalies in fetuses prenatally diagnosed with esophageal atresia

Esophageal atresia (EA) is a congenital anomaly occurring in 2.3 per 10,000 live births. Due to advances in prenatal imaging, EA is more readily diagnosed, but data on the associated genetic diagnoses, other anomalies, and postnatal outcome for fetuses diagnosed prenatally with EA are scarce. We collected data from two academic medical centers (n = 61). Our data included fetuses with suspected EA on prenatal imaging that was confirmed postnatally and had at least one genetic test. In our cohort of 61 cases, 29 (49%) were born prematurely and 19% of those born alive died in the first 9 years of life. The most commonly associated birth defects were cardiac anomalies (67%) and spine anomalies (50%). A diagnosis was made in 61% of the cases; the most common diagnoses were vertebral defects, anal atresia, cardiac anomalies, tracheoesophageal fistula with esophageal atresia, radial or renal dysplasia, and limb anomalies association (43%, although 12% met only 2 of the criteria), trisomy 21 (5%), and CHARGE syndrome (5%). Our findings suggest that most fetuses with prenatally diagnosed EA have one or more additional major anomaly that warrants a more comprehensive clinical genetics evaluation. Fetuses diagnosed prenatally appear to represent a cohort with a worse outcome.