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Assessment of fetal brain abnormalities
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Holoprosencephalies are classified into three varieties: alobar, semilobar, and lobar types. Facial abnormalities such as cyclopia, ethmocephaly, cebocephaly, flat nose, cleft lip, and palate are invariably associated with holoprosencephaly and extracerebral abnormalities. Facial abnormalities are often associated with holoprosencephaly.
Common Tips on Communication
Published in Justin C Konje, Complete Revision Guide for MRCOG Part 3, 2020
Your baby has a major abnormality involving the development of the brain. This abnormality is called holoprosencephaly. Normally, the brain divides into two halves (hemispheres) during early development. Holoprosencephaly occurs when the brain fails to divide properly into the right and left hemispheres. Where the abnormality is so severe, the babies tend to die before birth, but in the less severe cases, the babies are born with normal or near-normal brain development and facial deformities that may affect the eyes, nose and upper lip. There are three types of this abnormality, depending on how severe the abnormality is. These types are (a) alobar, where the brain has not divided at all, and it is the one that typically is associated with facial features; (b) semi-lobar, where the division of the brain into hemispheres (or lobes) is incomplete; and (c) lobar, in which there is a separation of the hemispheres. In some cases of lobar holoprosencephaly, the baby’s brain is nearly normal.
Fetal Alcohol Syndrome
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
Margaret P. Adam, H. Eugene Hoyme
It has been recognized that in utero alcohol exposure can be associated with holoprosencephaly, a developmental field defect in which there is failure of the embryonic forebrain to undergo midline cleavage in order to form the two cerebral hemispheres (30). The embryonic forebrain gives rise to the cephalic premigratory and migratory neural crest, which populate midfacial structures. Therefore, abnormalities in the premigratory and migratory neural crest result in a range of facial dysmorphology, from cyclopia to midface hypoplasia. It is hypothesized that neuronal death in this region leads to deficient tissue for midfacial development, thus contributing to many of the facial features present in FAS, such as the smooth philtrum and thin upper lip.
A Comprehensive Assessment of Co-occurring Birth Defects among Infants with Non-Syndromic Anophthalmia or Microphthalmia
Published in Ophthalmic Epidemiology, 2021
Jeremy M. Schraw, Renata H. Benjamin, Daryl A. Scott, Brian P. Brooks, Robert B. Hufnagel, Scott D. McLean, Hope Northrup, Peter H. Langlois, Mark A. Canfield, Angela E. Scheuerle, Christian P. Schaaf, Joseph W. Ray, Han Chen, Michael D. Swartz, Laura E. Mitchell, A.J. Agopian, Philip J. Lupo
Some of the observed combinations may be indicative of known syndromes or sequences. Examples of such include autosomal recessive conditions Manitoba-oculo-tricho-anal syndrome (MOTA; OMIM 248450), due to biallelic pathogenic variants in FREM1, and Microphthalmia with Limb Anomalies (MLA, OMIM 206920) caused by biallelic pathogenic variants in SMOC1. MOTA manifests with anophthalmia/microphthalmia, choanal atresia, omphalocele and/or scalp anomalies,26–28 and microphthalmia with limb anomalies. MLA includes anophthalmia/microphthalmia and spinal or limb anomalies. Combinations involving nasal anomalies and/or orofacial clefts may be indicative of holoprosencephaly sequence.29 In contrast, there are few reports on the co-occurrence of anophthalmia/microphthalmia with limb, rib, and cardiac defects30–32 and combinations involving these defects may represent unrecognized malformation syndromes. For example, Kariminejad et al. describe an infant with bilateral anophthalmia, hydrocephalus, cleft lip, and palate, ventricular septal defect, and shortness of the limbs and ribs among other anomalies. They propose that this phenotype may represent a novel ciliopathy similar to reported short-rib polydactyly syndromes.31,33
Investigation of copeptin levels in foetal congenital central nervous system anomalies
Published in Journal of Obstetrics and Gynaecology, 2021
Gestational age is a very important parameter for normal ultrasound appearance of the CNS. For example, the corpus callosum cannot be detected at 14 weeks of gestation because these structures appear after the 18–20th week of gestation (Balakumar 2004). On the other hand, the other technical factors that may cause inadequate ultrasound images are poor foetal position, obesity and oligohydramnios, so early detection of CNS by a non-invasive highly sensitive biomarker becomes important. Syngelaki et al. documented in their series of 44,859 cases that 100% of acrania and allobar holoprosencephaly could be diagnosed at 11–13 weeks of gestation. However, none of the case of corpus callosum agenesis, semilobar holoprosencephaly, and cerebellar or vermian hypoplasia, could be diagnosed in the first trimester (Syngelaki et al. 2011). Dane and colleagues found that 10 of 17 patients who had first trimester foetal anomaly had cranial anomaly and Grande et al showed that only 53% of the central nervous system anomalies can be diagnosed by ultrasonographic examination performed between the 11th and 14th gestational weeks (Dane et al. 2007; Grande et al. 2012).
Is the presence of corpus callosum predictable in the first trimester?
Published in Journal of Obstetrics and Gynaecology, 2018
Hakan Kalaycı, Ebru Tarım, Halis Özdemir, Tayfun Çok, Ayşe Parlakgümüş
Li et al. (2014) analysed 620 single foetuses between 11 and 13.6 weeks of gestation and found larger MB measurements and MB:F ratios (≥1) in five foetuses with a diagnosis of ACC and 13 foetuses with holoprosencephaly. Lachmann et al. (2013) searched their database to measure MB and F lengths and to calculate the MB:F ratio in 15 patients with ACC and 500 control patients. They found that MB diameter in the ACC group was greater than the 95th percentile for that measure in the control group in eight (53.3%) cases, and the F diameter was lower than the 5th percentile for that measure in six (40.0%) cases. In addition, the MB:F ratio was greater than the 95th percentile in 13 patients with ACC (86.7%). In our study, the 95th percentile of the MB:F ratio was 0.79. In addition, all ratios were <95th percentile at times during pregnancy, which confirmed with 100% sensitivity that no ACC was detected at the second-trimester screening.