Impact of elective termination on the occurrence of severe birth defects identified in a hospital-based active malformations surveillance program (1999 to 2002).

BACKGROUND: The number of affected infants and the types of malformations identified by a malformation surveillance programs can be impacted if elective terminations for malformations are not included. METHODS: The occurrence of malformations in all newborn infants was determined in a daily review of the findings in the pediatricians' examinations and those of all consultants. In addition, the findings in autopsies of all elective terminations were reviewed to identify all fetuses with structural abnormalities. A severity scale was used to subdivide the malformations. To establish the impact of elective termination, the malformed infants identified in the Active Malformations Surveillance Program at Brigham and Women's Hospital in Boston were analyzed for the 2 years before and after the hospital decreased significantly the number of elective terminations temporarily (1999-2000 vs. 2001-2002). The effect on the number of malformations identified at birth, as well as malformations of greater severity, was determined. RESULTS: The number of terminated fetuses with malformations decreased dramatically after termination services were interrupted (p < 0.0001). There were no differences in the prevalence rates of all malformations in the 2 years before and after the change in access to elective terminations. However, there were significant decreases in the number of infants identified with lethal/life-limiting and severe/handicapping malformations. CONCLUSION: In the surveillance for malformations among newborn infants, the inclusion of malformed fetuses from elective terminations had a significant effect on the number of infants with the more severe malformations identified. Birth Defects Research (Part A) 106:659-666, 2016. © 2016 Wiley Periodicals, Inc.

Congenital talipes equinovarus: frequency of associated malformations not identified by prenatal ultrasound.

OBJECTIVES: To establish the frequency of prenatally undetected associated malformations (identified at birth) in infants with apparent "isolated" club foot deformity. METHODS: A cohort study of all infants with unilateral or bilateral club foot deformity identified at birth among 311 480 infants surveyed between 1972 and 2012 at Brigham and Women's Hospital in Boston. Those with talipes equinovarus were divided into "isolated" and "complex", based on the findings in examination and by chromosome analysis. RESULTS: One hundred and forty-two infants had "isolated" talipes equinovarus (TEV), and 66 had the "complex" type. Six (4.2%) of the 142 infants with "isolated" TEV were found at birth to have associated malformations that had not been identified by imaging during pregnancy. These abnormalities included hip dislocation (n = 2), bilateral post-axial polydactyly of the feet (n = 1), penile chordee (n = 1), and hypospadias (n = 2). CONCLUSION: In this consecutive series of infants with isolated talipes equinovarus, 95.8% had no additional malformations identified by examination at birth. None of the additional findings were severe enough to affect the medical prognosis of the affected infant. © 2014 John Wiley & Sons, Ltd.

Iniencephaly.

BACKGROUND: Iniencephaly is a severe developmental abnormality of the craniovertebral junction in which the head is retroflexed dramatically. Anatomic studies have identified striking changes in the vertebrae and skull: marked lordosis of the cervical vertebrae, duplicated cervical vertebrae, irregularly fused cervical vertebrae, a widened foramen magnum and a small posterior fossa. The affected infant appears to have no neck, as the skin of the face is continuous with the chest and the skin of the posterior scalp is continuous with the skin of the back. Iniencephaly is considered a rare neural tube defect. The frequency has been higher in geographic areas in which the rates of occurrence of anencephaly and myelomeningocele were high. Most affected fetuses are either stillborn or die soon after birth. However, one affected individual is an adult with normal intelligence. METHODS: A malformations surveillance program can identify an unselected group of infants with iniencephaly. This approach can determine the prevalence rate, the frequency of associated malformations, and the occurrence of close relatives with other neural tube defects. RESULTS: Over 41 years, the surveillance of 289,365 births identified eight fetuses and newborn infants with iniencephaly. Five of the eight had either an additional encephalocele or a thoracic myelomeningocele. Two of the eight affected infants had a sibling or a cousin with anencephaly. CONCLUSION: These findings suggest a relationship between the occurrence of iniencephaly and the most common neural tube defects, anencephaly and myelomeningocele. Recent experience confirms that this complex neural tube defect is not always lethal. Birth Defects Research 110:128-133, 2018. © 2018 Wiley Periodicals, Inc.

Malformations attributed to the process of vascular disruption.

BACKGROUND: Several malformations have been attributed to the process of vascular disruption. The central hypothesis for this etiology is that blood flow to a structure has been altered after that structure had formed normally. The decreased blood flow leads to hypoxia, endothelial cell damage, hemorrhage, tissue loss, and repair. After recovery, some structures are normal and others show either tissue loss or structural abnormalities, such as syndactyly and constriction rings. METHODS: The phenotypic features of the 7,020 infants with one or more malformations, who were born to women who had always planned to deliver at Brigham and Women's Hospital (BWH) between, 1972 and 2012, that is, maternal nontransfers, were reviewed. The phenotypes associated with vascular disruption, such as the amniotic band syndrome and terminal transverse limb defects (TTLD), were identified. RESULTS: One hundred and five fetuses and infants had malformations attributed to the process of vascular disruption. Some specific causes of the amniotic band limb deformity were identified. TTLD with associated small digit-like nubbins occurred at three levels: proximal forearm, wrist, and metacarpal-phalangeal joint. Other causes included severe hemoglobinopathies and exposures to misoprostol and to prenatal procedures. CONCLUSIONS: Malformations attributed to the process of vascular disruption were a distinctive entity, among the recognized etiologies. The timing of the causative event in the first trimester was established for infants with exposures to either the prostaglandin misoprostol or the prenatal diagnosis procedure chorionic villus sampling. One challenge is to identify the developmental steps in vascular disruption when no causative exposure can be identified.

Malformations among 289,365 Births Attributed to Mutations with Autosomal Dominant and Recessive and X-Linked Inheritance.

BACKGROUND: The number of malformations attributed to mutations with autosomal or X-linked patterns of inheritance has increased steadily since the cataloging began in the 1960s. These diagnoses have been based primarily on the pattern of phenotypic features among close relatives. A malformations surveillance program conducted in consecutive pregnancies can identify both known and "new" hereditary disorders. METHODS: The Active Malformations Surveillance Program was carried out among 289,365 births over 41 years (1972-2012) at Brigham and Women's Hospital in Boston. The findings recorded by examining pediatricians and all consultants were reviewed by study clinicians to establish the most likely diagnoses. The findings in laboratory testing in the newborn period were reviewed, as well. RESULTS: One hundred ninety-six (0.06%) infants among 289,365 births had a malformation or malformation syndrome that was attributed to Mendelian inheritance. A total of 133 (68%) of the hereditary malformations were attributed to autosomal dominant inheritance, with 94 (71%) attributed to apparent spontaneous mutations. Forty-six (23%) were attributed to mutations with autosomal recessive inheritance, 17 associated with consanguinity. Seventeen (9%) were attributed to X-linked inheritance. Fifteen novel familial phenotypes were identified. The family histories showed that most (53 to 71%) of the affected infants were born, as a surprise, to healthy, unaffected parents. CONCLUSION: It is important for clinicians to discuss with surprised healthy parents how they can have an infant with an hereditary condition. Future studies, using DNA samples from consecutive populations of infants with malformations and whole genome sequencing, will identify many more mutations in loci associated with mendelizing phenotypes. Birth Defects Research 110:92-97, 2018.© 2018 Wiley Periodicals, Inc.

Causes of Congenital Malformations.

BACKGROUND: Many different causes of malformations have been established. The surveillance of a consecutive population of births, including stillbirths and elective terminations of pregnancy because of fetal anomalies, can identify each infant with malformations and determine the frequency of the apparent etiologies. This report is a sequel to the first such analysis in the first 10 years of this Active Malformations Surveillance Program (Nelson and Holmes, ). METHODS: The presence of malformations was determined among 289,365 births over 41 years (1972-2012) at the Brigham and Women's Hospital in Boston. The abnormalities were identified from the review of the examination findings of the pediatricians and consultants and diagnostic testing for the live-born infants and the autopsies of the fetuses in elective terminations and stillbirths. RESULTS: A total of 7020 (2.4%) infants and fetuses with one or more malformations were identified with these apparent etiologies in 26.6%: Mendelian disorders, including infants with postaxial polydactyly, type B; chromosome abnormalities; vascular disruption; complications of monozygous twinning; and environmental factors. The malformations of unknown etiology were a much larger group. CONCLUSION: While several causes of malformations have been identified, many remain unexplained. Combining the ascertainment in a future surveillance programs with genome sequencing and chromosome microarray analysis will increase significantly the number of malformations attributed to genetic mechanisms. Birth Defects Research 110:87-91, 2018.© 2018 Wiley Periodicals, Inc.

Hypospadias, Intrauterine Growth Restriction, and Abnormalities of the Placenta.

BACKGROUND: Hypospadias is more common among male infants with growth restriction, defined as a birth weight less than the 10th centile, than in infants with a normal birth weight. Intrauterine growth retardation (IUGR) has been associated, also, with abnormalities of the placenta, such as maternal vascular malperfusion. In a consecutive sample of newborn infants, the association between hypospadias, IUGR and abnormalities of the placenta could be analyzed. METHODS: Affected infants were identified among 289,365 liveborn and stillborn infants in the Active Malformations Surveillance Program between 1972 and 2012. The four anatomic locations of the ectopic urethral opening, based on the recorded physical examination findings, were: (1) glandular; (2) subcoronal; (3) penile; (4) penoscrotal. Affected infants with associated malformations, a chromosome abnormality, teratogenic exposure, maternal diabetes mellitus, or multiple gestations were excluded. RESULTS: Three hundred sixteen affected infants were identified: 52.2% glandular, 11.7% subcoronal, 27.8% penile, and 8.2% penoscrotal. The highest frequency of IUGR (34.6%) was in the infants with the most severe hypospadias (penoscrotal). The 39 reports of placenta findings showed a high frequency of abnormalities. CONCLUSION: An increased rate of occurrence of hypospadias and abnormalities of the placenta were present in infants with intrauterine growth restriction. The postulated cause of this association is a deficiency in the function of the placenta during weeks 10 to 14 of gestation when normal masculinization occurs due to an increase in the level of placental human chorionic gonadotropin and fetal testosterone. The cause of the placental deficiency has not been established. Birth Defects Research 110:122-127, 2018.© 2017 Wiley Periodicals, Inc.

Polydactyly, postaxial, type B.

BACKGROUND: Postaxial polydactyly, type B is the most common type of polydactyly. The vestigial sixth finger is attached by a narrow neurovascular pedicle to the lateral aspect of the hand or foot at the level of the metacarpal-phalangeal joint or the metatarsal-phalangeal joint. The occurrence of this type of polydactyly varies among racial groups, by sex and sidedness. Postaxial polydactyly, type A is a fully developed extra digit on the lateral aspect of the hand or foot with a bifid fifth or sixth metacarpal/metatarsal and is much less common. METHODS: In a malformations surveillance program, the frequency in racial groups, sex ratio and the frequency of other anomalies can be established. RESULTS: Five hundred forty-five affected infants were identified from 1972 to 2012 in the surveillance of 289,365 liveborn and stillborn infants and elective terminations because of fetal anomalies detected prenatally. Postaxial polydactyly, type B was an isolated anomaly in 95% of the affected newborns. There were more affected males than females. Black infants were affected more often than White infants: 0.91/100 vs. 0.035/100 infants. The dangling extra digit was much more common in the hands than in the feet. CONCLUSIONS: Postaxial polydactyly, type B is almost always an isolated, mild malformation with no medical significance. Postaxial polydactyly, types B and A occurred in several infants, suggesting that either the underlying mutation(s) can cause both types of postaxial polydactyly or that some affected infants have more than one mutation. Autosomal dominant inheritance with variable expressivity is postulated.

The Active Malformations Surveillance Program, Boston in 1972-2012: Methodology and demographic characteristics.

BACKGROUND: Malformations surveillance programs have been carried out in consecutive populations of newborn infants at single hospitals, as well as in several hospitals in defined populations. A surveillance program begins with the review of the findings recorded by the examining pediatrician in each infant's medical record. The results of diagnostic tests, consultations, and imaging studies are obtained, also, from that infant's medical record. Some malformations surveillance programs identify additional malformations over several months, as the infants have hospitalizations and additional diagnostic testing. METHODS: 289,365 infants (liveborn, stillborn, and fetuses in pregnancies terminated because of anomalies) were surveyed from 1972 to 2012 at an urban maternity center in Boston to identify each infant with one or more malformations. Each mother was interviewed to obtain demographic characteristics, results of prenatal testing, family history, and information about exposures in pregnancies. Specific diagnoses were established by the study geneticists. RESULTS: 7,020 (2.4%) of the 289,365 infants surveyed had one or more malformations. The etiologies identified included chromosome abnormalities, phenotypes attributed to dominant or recessive autosomal or X-linked mutations, vascular disruption, environmental factors, and complications of twinning. CONCLUSION: The surveillance of a large consecutive population of newborn infants, stillbirths, and aborted fetuses can identify with high reliability all infants with one or more malformations. This process of ascertainment of affected newborns can be used to improve genetic counseling, identify "new" phenotypes, and serve as a system for testing new technologies to establish more causes of congenital malformations.

Stillborn Infants: Associated Malformations.

BACKGROUND: Stillbirth, defined as death of a fetus in utero after 20 weeks of gestation, occurs in 1 to 2% of pregnancies in the United States. Many of these stillborn infants have associated malformations, including chromosome abnormalities, neural tube defects, and malformation syndromes. Other causes are abnormalities of the placenta and maternal conditions, such as pre-eclampsia and obesity. A consecutive sample of malformed stillborn infants can establish the relative frequency and severity of the associated malformations. METHODS: Stillbirths were identified in the Active Malformations Surveillance Program at Brigham and Women's Hospital (1972-2012). The findings at autopsy, including the findings in the placenta and the results of diagnostic studies, were compiled. RESULTS: One hundred twenty-seven stillborn infants with malformations were identified at autopsy among 289,365 pregnancies, including trisomies 21, 18, and 13; 45,X; triploidy; anencephaly; lower urinary tract obstruction; holoprosencephaly and severe heart defects, such as hypoplastic left heart syndrome and tetralogy of Fallot with pulmonary atresia. The severity of the abnormalities in stillborn infants was more severe than the spectrum of abnormalities identified in live-born infants. CONCLUSION: An autopsy of the stillborn fetus, including chromosome microarray and an examination of the placenta, can identify the underlying causes of the stillbirth. This review of stillborn fetuses with malformations showed that several different lethal malformations and heart defects are more common than among live-born infants. These postmortem examinations can improve the counseling of the parents about risks in future pregnancies. Birth Defects Research 110:114-121, 2018.© 2018 Wiley Periodicals, Inc.

Triploidy: Variation of Phenotype.

OBJECTIVES: Triploidy (69, XXX; 69, XXY; 69, XYY) accounts for 1% of conceptions, but the affected fetus often does not survive past the first trimester. Fetal development in triploidy is rare. A consecutive series was used to describe the fetal and placental phenotypes and compare them with previous publications. METHODS: Fifty-four triploid fetuses were identified in the Active Malformations Surveillance Program between 1972 and 2012 at Brigham and Women's Hospital in Boston. The phenotype was described from prenatal imaging and autopsy findings. RESULTS: The diagnosis was confirmed by chromosome analysis in 53 of the 54 fetuses. Twenty-seven (50%) of the affected fetuses were identified during pregnancy. The abnormalities identified by prenatal ultrasound included renal malformations, heart defects, hydrocephalus, holoprosencephaly, and myelomeningocele. At autopsy, syndactyly, usually between fingers 3 and 4, was identified in 37 (69%) of the fetuses. Thirteen (24%) of the infants had the histologic features of a partial hydatidiform mole in the placenta. CONCLUSIONS: The presence of major malformations and growth restriction during pregnancy makes triploidy a potential diagnosis. There are no obligate clinical features in triploidy. Syndactyly, especially 3-4 syndactyly of the hands, is a distinctive feature. Cystic changes in the placenta can be seen by ultrasound during pregnancy. There was no difference in the phenotype between triploid infants associated with partial moles and those with nonmolar placentas.