Folic acid and birth malformations

Orofacial Clefts: Genetics of Cleft Lip and Palate

Orofacial clefting is considered one of the commonest birth defects worldwide. It presents as cleft lip only, isolated cleft palate or cleft lip and palate. The condition has a diverse genetic background influenced by gene-gene and gene-environment interaction, resulting in two main types, syndromic and nonsyndromic orofacial clefts. Orofacial clefts lead to significant physiological difficulties that affect feeding, speech and language development and other developmental aspects, which results in an increased social and financial burden on the affected individuals and their families. The management of cleft lip and palate is solely based on following a multidisciplinary team approach. In this narrative review article, we briefly summarize the different genetic causes of orofacial clefts and discuss some of the common syndromes and the approach to the management of orofacial clefts.

[Cleft lip and palate : One of the most frequent congenital malformations]

With a frequency of 1 per 500 live births, a cleft lip and palate is one of the most frequent congenital malformations. Untreated, it leads to disturbances in feeding, speech, hearing, tooth position and esthetics. A multifactorial genesis is assumed. The fusion of the different facial processes takes place in the first 3 months of pregnancy and a cleft can develop during this time. Surgical treatment includes the early anatomical and functional restoration of the affected structures within the first year of life in order to enable normal intake of food, articulation, nasal breathing and middle ear ventilation. Breastfeeding is possible in children with a cleft formation but alternative feeding methods, such as finger feeding, often have to be used. In addition to the surgery for primary closure of the cleft, otorhinolaryngological (ENT) interventions, speech therapy, orthodontic treatment as well as other surgical interventions are part of the interdisciplinary treatment concept.

Risk of congenital malformations among offspring of mothers and fathers with celiac disease: a nationwide cohort study

BACKGROUND & AIMS

Many patients with celiac disease experience malabsorption, weight loss, and anemia; undiagnosed celiac disease during pregnancy has been linked with adverse outcomes. Studies of celiac disease and congenital malformations in offspring have been underpowered. We investigated the risk of congenital malformations among the offspring of parents with celiac disease.

METHODS

We performed a nationwide cohort study of data from linked health care registers in Sweden from 1973 through 2009. We collected histopathology data from 28 pathology departments in Sweden to identify individuals with celiac disease (based on the presence of villous atrophy). We estimated the risks of malformations in the offspring of mothers and fathers with and without celiac disease. Logistic regression was used to estimate adjusted prevalence odds ratios (aPORs) with 95% confidence intervals (CIs).

RESULTS

Among 11,382 offspring of mothers with celiac disease, there were 672 cases (5.9%) of malformation compared with 2098 cases (5.1%) among 40,922 offspring of mothers without celiac disease. Similarly, 352 (5.9%) of 6002 offspring of fathers with celiac disease and 1009 (5.1%) of 19,600 offspring of fathers without celiac disease had a malformation. In adjusted analyses, the offspring of mothers or fathers with celiac disease had a slightly increased risk of having children with malformations (for those with mothers with celiac disease: aPOR, 1.15; 95% CI, 1.05-1.26; for those with fathers with celiac disease: aPOR, 1.14; 95% CI, 1.00-1.29). However, these excess risks decreased or vanished entirely when we restricted our data to births since 2000 (for those with mothers with celiac disease: aPOR, 1.11; and 95% CI, 0.79-1.56; for those with fathers with celiac disease: aPOR, 1.01; 95% CI, 0.81-1.26).

CONCLUSIONS

In a nationwide study, we found an increased risk for malformation among the offspring of mothers or fathers with celiac disease. However, the excess risk is small; the upper limits of the CIs for malformation indicate a 29% maximum relative increase.

Effect of interpregnancy interval on adverse perinatal outcomes--a national study

BACKGROUND

The interpregnancy interval (IPI) has been reported to influence the outcome of pregnancy and birth. We performed a national study in Israel to determine the impact of IPI on multiple adverse perinatal outcomes.

STUDY DESIGN

This longitudinal cohort study used birth certificates of siblings born to the same biological mother, with at least one previous birth and a subsequent singleton pregnancy. Adverse pregnancy outcomes included preterm delivery, very preterm birth, small for gestational age (SGA), very SGA (VSGA), early neonatal death and major congenital malformations. Multivariate logistic regression was performed for each outcome.

RESULTS

The study included 440,838 of a total of 846,845 reported live births in Israel over 5 years; excluded were primiparas (32%), multifetal births (4.9%) and those with incomplete data (10.9%). For IPIs shorter than 6 months, there were significantly increased risks for preterm birth (OR=1.23), SGA (OR=1.14), VSGA (OR=1.15), early neonatal death (OR=1.62) and congenital malformations (OR=1.14). Intervals of 60 months or longer had higher risks for preterm birth (OR=1.39) and VSGA (OR=1.16).

CONCLUSION

Optimal IPI recommendation of >11 months is an accessible and low-cost means to improve multiple adverse perinatal outcomes.

Socio-occupational status and congenital anomalies

BACKGROUND

The aim of this study is to investigate the association between socio-occupational status and the frequency of major congenital anomalies in offspring.

METHODS

The study population comprised 81,435 live singletons born to mothers enrolled in the Danish National Birth Cohort between 1996 and 2002. A total of 3352 cases of major congenital anomalies (EUROCAT criteria) were identified by linkage to the National Hospital Discharge Register. Malformations were recorded at birth or in the first year of life. Information about maternal and paternal socio-occupational status was collected prospectively using telephone interviews in the second trimester of pregnancy and was categorized as high, middle or low. Associations were measured as relative prevalence ratios using the highest socio-occupational status within the couple as the reference group.

RESULTS

The prevalence of all recorded major congenital anomalies was similar, about 4%, in all the socio-occupational categories. Low social status of the couple did, however, correlate with a higher prevalence of congenital anomalies of the 'respiratory system'. No association was substantially attenuated when we adjusted for maternal and paternal age, smoking status, maternal alcohol habits, folic acid intake and body mass index. When malformations of the heart and the cardiovascular system were grouped together, they were more frequent in families where both parents presented a low socio-occupational status.

CONCLUSION

We detected an association between low socio-occupational status and congenital anomalies of the respiratory system, the heart and the circulatory system. These malformations are good candidates for a large study on occupational, environmental and social determinants.

Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms resulting in suboptimal oocyte maturation: a discussion of folate status, neural tube defects, schizophrenia, and vasculopathy

Several conditions apparent at birth, e.g., neural tube defects (NTDs) and cardiac anomalies, are associated with polymorphisms in folate-related genes, such as the 677C → T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene. Similar associations have been established for several constitutional chronic diseases in adulthood, such as schizophrenia, cardiovascular diseases, dementia, and even neoplasias in different organ systems. This spectrum of developmental anomalies and constitutional diseases may be linked to high-risk conceptions related to preovulatory overripeness ovopathy (PrOO). Some developmental anomalies, such as NTDs, are to a large extent prevented by supplementation of folic acid before conception, but supplementation does not seem to prevent cardiovascular disease or cognitive decline. These diverging results can be elucidated by introduction of the PrOO concept, as MTHFR polymorphisms and inherent low folate levels induce both non-optimal maturation of the oocyte and unsuccessful DNA methylation and demethylation, i.e. epigenetic mutations. The PrOO concept is testable and predicts in a random population the following: (1) female carriers of specific genetic MTHFR variants exhibit more ovulatory disturbances and inherent subfecundity traits, (2) descendents from a carrier mother, when compared with those from a wild-type mother, are more frequently conceived in PrOO high-risk conditions and, thus, (3) disadvantaged in life expectancy. If so, some MTHFR polymorphisms represent a novel, genetically determined, PrOO high-risk conception category comparable to those which are environmentally and behaviorly influenced. These high-risk conditions may cause developmental anomalies and defective epigenetic reprogramming in progeny. The interaction between genetic and environmental factors is a plausible mechanism of multifactorial inheritance.