ABSTRACT The first trimester has been evaluated at different exposures as the critical period of congenital abnormalities. However, the first trimester concept has no scientific basis because environmental agents (teratogens) cannot induce congenital abnormalities during the first gestational month calculated from the first day of the last menstrual period. In addition, the critical period of some congenital abnormalities, for example, hypospadias occurs after the first trimester). Different congenital abnormalities have different critical periods and computer-based evaluation programs help to evaluate different specified congenital abnormalities according to their specific critical periods separately. Thus, this new and feasible approach is recommended for epidemiological and clinical studies in the future after an international consensus in the specified critical periods of different congenital abnormalities. The author of this Commentary proposes a detailed database for this approach for discussion because a consensus may be achieved only after the confirmation or modification of these critical periods.
ABSTRACT Maternal alcohol ingestion during pregnancy adversely affects the developing fetus, often leading to fetal alcohol syndrome (FAS). One of the most severe consequences of FAS is brain damage that is manifested as cognitive, learning, and behavioral deficits. The hippocampus plays a crucial role in such abilities; it is also known as one of the brain regions most vulnerable to ethanol-induced neurotoxicity. Our recent studies using morphometric techniques have further shown that ethanol neurotoxicity appears to affect the development of the dentate gyrus in a region-specific manner; it was found that early postnatal ethanol exposure causes a transitory deficit in the hilus volume of the dentate gyrus. It is strongly speculated that such structural modifications, even transitory ones, appear to result in developmental abnormalities in the brain circuitry and lead to the learning disabilities observed in FAS children. Based on reports on possible factors deciding ethanol neurotoxicity to the brain, we review developmental neurotoxicity to the dentate gyrus of the hippocampal formation.
ABSTRACT The temporomandibular joint (TMJ) consists of the mandibular condyle and the articular eminence of the temporal bone. The morphological development of the TMJ during prenatal life lags behind other joints in terms of both the timing of its appearance and its progress. At birth, the joint is still largely underdeveloped. There are many causes of the various growth disturbances and abnormalities of the mandibular condyle and related structures. Growth disturbances in the development of the mandibular condyle may occur in utero late in the first trimester and may result in disorders such as aplasia or hypoplasia of the mandibular condyle. Meanwhile, hyperplasia of the mandibular condyle is not visible at birth and seems to be gradually acquired during growth. In the present review article, the congenital abnormalities of the mandibular condyle are classified morphologically into three major groups and two subgroups from a clinical standpoint: (1) hypoplasia or aplasia of the mandibular condyle, including (i) primary condylar aplasia and hypoplasia, (ii) secondary condylar hypoplasia; (2) hyperplasia; and (3) bifidity. In addition, the molecular-based etiology of anomalies of the mandibular condyle is also discussed.
ABSTRACT Multiple congenital abnormalities (MCA) represent the most severe category of structural birth defects, (i.e. congenital abnormalities [CA]). Unfortunately, most MCA are not recognized and/or identified as MCA syndromes or MCA associations in the clinical practice. The term unclassified MCA (UMCA) is used for this category of MCA. We decided to evaluate the component CA of UMCA cases. The population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities (1980–1996) was evaluated. ‘False’ MCA, such as complex CA, polytopic field defects and sequences were excluded from the category of MCA. In addition, MCA syndromes caused by chromosomal aberrations and major mutant genes with preconceptional origin were excluded from the dataset of the Surveillance. MCA syndromes caused by teratogens and MCA associations with well-defined component CA were also excluded in the study. Thus, only UMCA cases (i) without the recognition of previously delineated MCA syndromes (ii) and/or without the identification of new MCA syndromes or (iii) caused by random combination of CA were included in the study. We compared data from 1349 cases with UMCA, 2405 matched population controls without any CA, and 21 494 malformed controls with isolated CA. There was a higher rate of stillbirth and a moderate male excess in UMCA cases, a somewhat shorter gestational age at delivery and an obvious reduction in birthweight. The intrauterine fetal growth retardation and rate of low-birthweight newborns showed an association with the number of component CA in UMCA cases. A similar association was not found with gestational age and the rate of preterm birth. UMCA represent one of the most severe categories of CA. The degree of intrauterine fetal growth retardation depends on number of component CA in UMCA cases.
ABSTRACT Metabolic fingerprinting of amniotic fluid from streptozotocin-induced diabetic pregnant rats was performed using Fourier transform-ion cyclotron resonance mass spectrometry. Some of the fetuses from the diabetic pregnant rats exhibited ventricular septal defect. The positive ion profiles of amniotic fluids from diabetes were different to those of the control rats. The alteration of biochemical composition in the diabetic amniotic fluid suggests the presence of potential biomarkers to indicate progression of malformation under the diabetic pregnancy.
ABSTRACT Gastroschisis is a rare anomaly and is usually not associated with any other congenital anomalies. The embryology of gastroschisis and omphalocele remains a matter of speculation. Incidences of gastroschisis are particularly high among pregnancies in very young women. The present case is reported because of its rare association with the condition of gastroschisis, disrupted omphalocele, with aplasia of the foot and external genital organs, as well as imperforate anus with distal rectal atresia.
ABSTRACT Müllerian duct anomalies are infrequently encountered clinical problems and often present with difficulty in diagnosis. A high level of suspicion is the key to diagnosis, which is usually made soon after menarche. However, this is the first reported case of uterus didelphys with obstructed hemivagina and pyocolpos with ipsilateral renal agenesis in which the diagnosis was delayed until pregnancy.