Prenatal Diagnosis Of Neural Tube Defects Research Articles

Neural Tube Defect in a Resource Limited Setting: Clinical Profile and Short Term Outcome.

There is a huge burden of neural tube defect (NTD) in Ethiopia, and surgical management is not readily available. We aimed to assess the clinical profile and hospital outcome of children with NTD that were operated in Hawassa University Comprehensive Specialized Hospital, Hawassa, Ethiopia. A retrospective cross-sectional study on 250 children with NTD that were treated in a tertiary hospital from March 2016 to May 2020 was conducted to describe the clinical profile and treatment outcome at discharge. Logistic regression analysis was carried out to evaluate factors that determine mortality. Out of the 250 children, 50.4% were male. Myelomeningocele was the most common type of NTD (77.2%) followed by meningocele (10.4%). Only 3 mothers (1.2%) received periconceptional folic acid. Prenatal diagnosis of NTD was made in only 22 (8.8%) cases. 52.8% of the NTDs were ruptured at presentation and 50.8% had associated sepsis. At presentation, 42.4% were ≤72 hours of age and only 18 neonates (7.2%) were operated within 72 hours of admission. 54% had associated hydrocephalus, 31.6% had Chiari II malformation and 19.6% had club foot. Surgical site infection, post MMC repair hydrocephalus, and meningitis were seen in 8%, 14% and 16.8% of the participants, respectively. The mean duration of hospitalization was 24 ± 14.4 days. Twenty patients (8%) died before discharge from hospital. Prematurity [AOR: 26 (95% CI: 8.01, 86.04), P < 0.001] and the presence of meningitis [AOR: 3.8 (95% CI: 1.12,12.9), P = 0.03]were determinants of mortality. NTDs are substantial health problem in this part of the country. Periconceptional folic acid supplementation is almost non-existent. Prenatal detection of NTDs is very low and management is delayed in the majority of cases. Myelomeningocele is the most common type of NTD. There is high in-hospital mortality, and prematurity and the presence of meningitis are its determinants.

Prenatal ultrasound diagnosis of neural tube defects in the era of intrauterine repair – Eleven years’ experiences

ObjectiveTo modify the current neural tube defect (NTD) classification for fetal medicine specialists, and to investigate the impact of prenatal ultrasound conus medullaris position screening on the detection rate of closed spinal dysraphism and pregnancy outcomes. Materials and methodsThe clinical data of 112 patients prenatally diagnosed with neural tube defects in Taiji clinic from 2008 to 2018 were retrospectively analyzed. All cases were classified following the modified classification. We compared the detection rate before and after introducing the conus medullaris screening and pregnancy outcomes for NTD types. ResultsClosed spinal dysraphism type prevailed in our sample (43.8%). The median gestational age at the time of detection for cranial dysraphism was 13.3 weeks, open spinal dysraphism was 22.0 weeks, and closed spinal dysraphism was 22.6 weeks. All cranial dysraphism (n = 43) and open spinal dysraphism cases (n = 20) had pregnancies terminated. For closed spinal dysraphism Class 1, the live-birth rate was 100.0% in the cases without other anomalies and 33.3% in the cases with other anomalies, respectively (X2 = 17.25, p < 0.001). Similarly, for Class 2, pregnancy continuation rate was 50.0% in cases without other anomalies and 20.0% in cases with other anomalies, yet it failed to reach statistical significance (X2 = 0.9, p = 0.524). ConclusionOur case series may help to improve early screening and prenatal diagnosis of NTDs. Modified classification is adjusted for use in ultrasound fetal care facilities, which could be used for predicting pregnancy outcome. We suggest promoting first-trimester anatomical screening in order to make an earlier diagnosis and therefore provide better prenatal care for open spinal dysraphism cases in the era of intrauterine repair. Our findings imply that the use of fetal conus medullaris position as a marker for closed spinal dysraphism improves the detection rate and would unlikely lead to a higher termination rate.

Fetal Pathology of Neural Tube Defects - An Overview of 68 Cases.

The prevalence of neural tube defects worldwide is 1 - 2 per 1000 neonates. Neural tube defects result from a disturbance of neurulation in the 3rd or 4th week of development and thus represent the earliest manifestation of organ malformation. Neural tube defects (NTD) are classified into cranial dysraphism leading to anencephaly or meningoencephalocele and spinal dysraphism with or without meningomyelocele. In isolated form they have multifactorial causes, and the empirical risk of recurrence in Central Europe is 2%. As associated malformations they tend to occur sporadically, and in monogenic syndromes they follow Mendelian inheritance patterns with a high risk of recurrence. Autopsies were performed on 68 fetuses following a prenatal diagnosis of NTD and induced abortion. The incidence of NTDs in our autopsied fetuses was 8% and 11% in fetuses with malformations. The percentage of fetuses with anencephaly, encephalocele or spina bifida was 24, 18, and 60%*, respectively. Analysis of the sex distribution showed a female preponderance in cranial dysraphisms but the sex distribution of spina bifida cases was equal. The extent and localization of NTDs varied, with lumbosacral cases clearly predominating. The proportion of isolated, associated and syndromic neural tube defects was 56, 23.5 and 20.6% respectively. In the majority of syndromes, the neural tube defect represented a not previously observed syndromic feature. The high proportion of NTDs with monogenic background underlines the importance of a syndrome oriented fetal pathology. At the very least it requires a thourough photographic and radiographic documentation of the fetal phenotype to enable the genetic counsellor to identify a syndromic disorder. This is necessary to determine the risk of recurrence, arrange confirming mutation analyses and offer targeted prenatal diagnosis in subsequent pregnancies.

Could microRNAs be biomarkers for neural tube defects?

Could microRNAs be biomarkers for neural tube defects?

Immunocytochemical Characterization of Amniotic Fluid Macrophages in Cases of Fetal Neural Tube Defects

Amniotic fluid cells from 31 pregnancies with fetuses having open neural tube defects (NTDs) and from 43 pregnancies with fetuses free of NTDs were studied with the use of the immunoperoxidase method for alpha-fetoprotein (AFP) and glial fibrillary acidic protein (GFAP). The authors also used cytochemical stains for endogenous peroxidase and nonspecific esterase activity. In cases of NTDs, macrophages were present in the amniotic fluid, and in the authors' system they showed intense immunoreactivity for both AFP and GFAP and showed very strong activity for peroxidase and nonspecific esterase, whereas the epithelial cells and red blood cells showed no activity. In six cases of anencephaly, sections from the margin of the cranial end of defective spinal cords at the aperture of the open lesion were also studied for AFP and GFAP. In these cases, AFP- and GFAP-positive cells were found, indicating the possible neural (glial) origin of a part of amniotic fluid macrophages. Although the determination of AFP levels in maternal blood and amniotic fluid is widely used in the prenatal diagnosis of NTDs, demonstration of AFP in amniotic fluid cells by means of immunocytochemistry has not been described.

PRENATAL DIAGNOSIS OF NEURAL-TUBE DEFECTS WITH A MONOCLONAL ANTIBODY SPECIFIC FOR ACETYLCHOLINESTERASE

An immunoassay for acetylcholinesterase (AChE), based on a monoclonal antibody (AE-2), gave the following results when applied to a panel of amniotic fluids: (a) among 651 samples with normal outcome and normal alphafetoprotein (AFP) values there were 2 (0·31 Wa) false positives; (b) of 9 samples with normal outcome and raised AFP values 1 had a raised AChE titre; (c) all 48 samples from anencephaly cases had raised AChE values; (d) among 49 samples from open spina bifida cases (2 of which had normal AFP values), 48 had raised AChE titres. It is suggested that a monoclonal-antibody-based immunoassay may displace polyacrylamide gel electrophoretic analysis of AChE as a complementary test to AFP in prenatal diagnosis of neural-tube defects, since it is a quantitative test largely independent of operator skill and experience.

Comparison of two methods for amniotic fluid cholinesterases identification in the qualitative test for prenatal diagnosis of neural tube defects

Neural tube defects (NTD) are one of the more common congenital abnormalities with a generally accepted multifactorial origin, including a persistent environmental factor as well as a genetic factor, but with the precise cause still not known. Prenatal diagnosis of NTD uses a marker that is not a product of a defective gene or an abnormal chromosome, but is based upon the detection of elevated a,-fetoprotein (AFP) in the amniotic fluid [l]. The introduction of the qualitative amniotic fluid acetylcholinesterase test, in 1979, by Smith et al and Chubb et al [2,3] has gained wide acceptance as a secondary biochemical diagnostic test for the prenatal detection of NTD, thus improving the accuracy of the diagnosis. Qualitative description of the type of acetylcholinesterase in human amniotic fluid shows a typical form of this enzyme only in cases of open neural tube defects, but not in normal pregnancies [4-61. Gel electrophoresis separates non-specific cholinesterase from acetylcholinesterase on the basis of differential mobility: amniotic fluid from normal pregnancies has a single band which is a non-specific cholinesterase (ChE; EC 3.1.1.8), while NTD pregnancies have, additionally, a slightly faster-moving band which is acetylcholinesterase (AChE; EC 3.1.1.7) [7-121. AChE may be distinguished, additionally, from the non-specific ChE by the response to specific inhibitors [13]. AChE was originally chosen as a potential biochemical marker of NTD because of changes in its concentration associated with the development of the nervous

Alpha-feto-protein during development and in disease.

An alpha-feto-protein (AFP) is present in many mammals, in birds, and in sharks during development. The AFP present in different species have similar physicochemical properties and often have common antigenic...