Relationship Between Gene-Phenotype and Clinical Manifestations of Chromosomal Copy Number Variations Indicated by Non-Invasive Prenatal Testing

Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.

Prenatal ultrasonic characteristics and diagnosis of fetal Currarino syndrome:Report of 2 cases and review of literature

Objective To explore prenatal ultrasonic characteristics of fetal Currarino syndrome(CS)and methods for prenatal diagnosis of CS.Methods Two fetuses with CS confirmed by genetic examination were retrospectively analyzed,while 6 CS fetuses with complete prenatal ultrasonic data in literature were reviewed.Prenatal ultrasonic characteristics of CS fetuses and the method for prenatal diagnosis of CS were discussed.Results Among 8 CS fetuses diagnosed with prenatal ultrasound,4 were female singletons with a clear family history of CS,and MNX 1 gene mutation was found in 1 fetus.The other 4 fetuses were 2 pairs of male monochorionic twins,all with MNX 1 gene mutation.Among 8 CS fetuses,complete triad(sacral agenesis abnormalities,anorectal malformation and presacral mass)were displayed only in 2 fetuses,while all 8 had sacral agenesis abnormalities and 6(6/8,75.00%)were detected with prenatal ultrasound,6 had low location of conus medullaris and 2(2/6,33.33%)detected with prenatal ultrasound.Conclusion Prenatal ultrasound was the first choice for non-invasive diagnosis of fetal CS.When one of sacral agenesis abnormalities,anorectal malformation and presacral mass was found with prenatal ultrasound,the possibility of CS should be considered,and fetal MRI,genetic examination and prenatal genetic counselling should be recommended if necessary.

Prenatal Diagnosis of an Apically Located Congenital Left Ventricular Aneurysm: A Rare Case

Congenital ventricular aneurysm is a very rare cardiac anomaly.A diagnosis can be made during the prenatal period using fetal echocardiography.This study presents a very rare apically located left ventricular aneurysm case,and the relevant literature was reviewed and discussed.In this case,a 35-year-old,gravida 2,parity 1 preg-nant woman at 24 weeks of gestation,displayed a wide aneurysmal image in the left ventricular apical wall on fetal echocardiography.There was a 1.79 mm muscular ventricular septal defect at the apical region of the interven-tricular septum.In the course of the color Doppler ultrasonography examination,an aberrantfibrous band within the left ventricle and consequent turbulentflow during systole were observed.The baby,born via cesarean section at 37 weeks of gestation,is now in its postnatal seventh month.However,during echocardiographic follow-ups,changes have been observed,including mild to moderate mitral insufficiency and a decrease in systolic function.Despite thesefindings,the clinical condition remains asymptomatic.It is of great importance to use a multidis-ciplinary approach in managing these rare cases that could lead to potential adverse outcomes during the antena-tal or postnatal periods.

Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports

BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women.

“Keyboard sign”and“coffee bean sign”in the prenatal diagnosis of ileal atresia:A case report

BACKGROUND Ileal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum.The overall diagnostic accuracy of prenatal ultrasound in detecting jejunal and ileal atresia is low.We report a case of ileal atresia diagnosed prenatally by ultrasound examination with the“keyboard sign”and“coffee bean sign”.CASE SUMMARY We report a case of ileal atresia diagnosed in utero at 31 weeks'of gestation.Prenatal ultrasound examination revealed two rows of intestines arranged in an‘S’shape in the middle abdomen.The inner diameters were 1.7 cm and 1.6 cm,respectively.A typical“keyboard sign”was observed.The intestine canal behind the“keyboard sign”showed an irregular strong echo.There was no normal intestinal wall structure,showing a typical“coffee bean sign”.Termination of the pregnancy and autopsy findings confirmed the diagnosis.CONCLUSION The prenatal diagnosis of ileal atresia is difficult.The sonographic features of the“keyboard sign”and“coffee bean sign”are helpful in diagnosing the location of congenital jejunal and ileal atresia.

Prenatal ultrasound diagnosis of fetal maxillofacial teratoma:Two case reports

BACKGROUND Facial teratoma is a rare benign tumor that accounts for about 1.6%of all teratomas and can be diagnosed by prenatal ultrasound(US).The purpose of this report was to describe our experience with the diagnosis of fetal facial teratoma by prenatal US at second trimester to provide a reference for clinical diagnosis of fetal maxillofacial teratoma.CASE SUMMARY We present two cases of patients with abnormal fetal facial findings on US at second trimester of pregnancy in our department.Case 1 was a 31-year-old G3 P1+1 female,with US revealing a heterogeneous echogenicity of 32 mm×20 mm×31 mm on the fetal face,most of it located outside the oral cavity and filling the root of the oral cavity.Case 2 was a 29-year-old G1P0 female,with fetal head and neck US revealing a cystic-solid echo mass measuring 42 mm×33 mm×44 mm,the upper edge of the lesion reaching the palate and filling the oral cavity.The contours of the lesions were visualized using three-dimensional(3D)US imaging.Both patients decided to give up treatment.Biopsies of the lesions were performed after induction of labor,and diagnosed as maxillofacial teratoma.CONCLUSION Fetal maxillofacial teratomas can be diagnosed by US in early pregnancy,allowing parents to expedite treatment decisions.

Invasive Procedures for Prenatal Diagnosis in Salmaniya Medical Complex in Bahrain: A Retrospective Cross-Sectional Descriptive Study

Background: Prenatal diagnosis is the process of evaluating the presence of disease or potential disease in the fetus, this enables families to be better prepared before the birth of the baby. There are non-invasive prenatal diagnosis procedures and invasive prenatal diagnosis procedures. The invasive prenatal diagnosis procedures are CVS (chorionic villus sampling) and amniocentesis. The American College of Obstetricians and Gynecologists states that invasive diagnostic testing should be available to all women, regardless of age or risk. Objective: To determine the indications, outcome and results of diagnostic invasive prenatal procedures. Study setting: The obstetrics and Gynecology Department in Salmaniya Medical Complex in Kingdom of Bahrain. Study design: Retrospective descriptive study. Study subjects and Methods: This retrospective descriptive study was conducted on 175 pregnant women who underwent invasive prenatal procedures (CVS and amniocentesis) between January 2013 and December 2018 at SMC in Kingdom of Bahrain. All medical records of the participants were reviewed and entered the study. According to the implemented procedures, medical records were categorized into two chorionic villus sampling (CVS) and amniocentesis groups. The study subject will include indications of the procedures which are advanced maternal age, hematological disorders, genetic disorders, metabolic disorders, abnormal structural findings in fetal ultrasound and previous child with aneuploidy. In addition, the study will address the complications, outcome and results of procedures. Results: About half of our indications of the procedures were due to hematological disorders (47.6%) followed by abnormal structural findings in fetal ultrasound (30.1%) then genetic disorders (15.7%), metabolic disorders (4.8%) and advanced maternal age (1.8%). Regarding complications of the procedure;threatened miscarriage or loss of pregnancy within 3 weeks was (2.3%), amniotic fluid leakage (0.7%), abdominal cramps (0.7%) and Insufficient or contaminated sample (6.2%). Regarding outcome of the pregnancy, our results showed that the loss of pregnancy was (4.8%), intrauterine fetal death or still birth was (13.9%), live birth was (63.9%), preterm delivery was (7.8%), preterm premature rupture of membrane (PPROM) was (1.8%), limbs reduction was (0.0%). Termination of pregnancy outside the country was (7.8%) of chorionic villus sampling and amniocentesis. Conclusion: CVS and amniocentesis are useful outpatient procedures to detect diagnosis or to assess whether a patient is at increased risk of having an affected fetus and that will minimize the psychological impact on the patient and to provide a proper antenatal care to the pregnant women by her obstetrician and follow up to the baby by pediatrician. In this study it was observed that most of the patients who underwent the procedure were couples either carrier or affected to sickle cell disease or Beta thalassemia.

Analysis of the Efficacy of Prenatal B-Ultrasound in Diagnosing Fetal Abnormalities

Objective:To explore the positive significance of using prenatal B-ultrasound in diagnosing fetal abnormalities.Methods:A total of 200 pregnant women who visited Shaanxi Provincial People’s Hospital between January 2023 and January 2024 were recruited as the research subjects.All pregnant women received prenatal examinations.A retrospective analysis was carried out to analyze the positive significance of prenatal B-ultrasound examination in the diagnosis of fetal abnormalities.Results:Prenatal B-ultrasound examination detected 10 cases of fetal abnormalities,with a detection rate of 5.00%.When compared with the postnatal examination results of 5.50%,the difference was insignificant(P>0.05).Moreover,comparing the fetal limb abnormalities and cardiovascular abnormalities in prenatal B-ultrasound examination and postnatal examination,one case of congenital heart disease was missed in the prenatal B-ultrasound examination,and the others were consistent with the postnatal examination results,with a coincidence rate of 90.91%,indicating a high compliance rate.Conclusion:Fetal abnormalities have a great impact on mothers,babies,and families,and it is particularly important to strengthen diagnosis during this process.Prenatal B-ultrasound examination can improve the accuracy of diagnosis of fetal abnormalities and can be promoted in clinical practice as a basis for screening fetal abnormalities.

Prenatal programing of motivated behaviors:can innate immunity prime behavior?

Prenatal programming during pregnancy sets physiological outcomes in the offspring by integrating external or internal stimuli.Accordingly,pregnancy is an important stage of physiological adaptations to the environment where the fetus becomes exposed and adapted to the maternal milieu.Maternal exposure to high-energy dense diets can affect motivated behavior in the offs p ring leading to addiction and impaired sociability.A high-energy dense exposure also increases the pro-inflammatory cytokines profile in plasma and brain and favors microglia activation in the offspring.While still under investigation,prenatal exposure to high-energy dense diets promotes structural abnormalities in selective brain regions regulating motivation and social behavior in the offspring.The current review addresses the role of energy-dense foods programming central and peripheral inflammatory profiles during embryonic development and its effect on motivated behavior in the offspring.We provide preclinical and clinical evidence that supports the contribution of prenatal programming in shaping immune profiles that favor structural and brain circuit disruption leading to aberrant motivated behaviors after birth.We hope this minireview encourages future research on novel insights into the mechanisms underlying maternal programming of motivated behavior by central immune networks.

Determination of the ovine ovarian reserve during the prenatal and neonatal periods

Objective:To determine the ovine ovarian histomorphology and follicular staging at various age periods in Awassi breed.Methods:Ovaries were collected from prenatal fetuses[gestational age(95±5)days],neonatal(day 0),and prepubertal ewe lambs(two and four months of age);each age group included six animals.Ovaries(n=12,each group)were dissected and processed for hematoxylin and eosin staining.Stained sections(n=24,each group)were imaged and utilized for histomorphology assessment,follicle measurement,and classification.Results:Prenatal ovaries were mainly enriched with primordial follicles accompanied by a lower proportion of primary follicles.In addition to primordial and primary follicles,neonatal ovaries demonstrated a proportion of centrally located multilayered and antral follicles.In comparison with neonatal ovaries,the proportion of multilayered and antral follicles was significantly higher in the ovaries of two-month-old lambs;conversely,the proportion of peripherally situated primordial follicles dramatically declined compared to that of earlier age of lamb.Although there was no statistical variation in the sizes of primordial follicles across groups,the mean diameter of the primary follicle in the prenatal ovaries was substantially smaller than in postnatal ovaries.Compared to the neonatal ovaries,the size of the multilayered and antral follicles in the prepubertal ovaries was substantially larger.Conclusions:The earliest follicular developmental stages were established prenatally whereas the advanced growth stages started in the neonatal period and greatly increased in the prepubertal period.

Confusing finding of quantitative fluorescent polymerase chain reaction analysis in invasive prenatal genetic diagnosis:A case report

BACKGROUND Quantitative fluorescent polymerase chain reaction(QF-PCR)is a rapid prenatal diagnostic method for abnormalities on chromosomes 21,18,and 13 and sex chromosomal aneuploidy.However,the value of QF-PCR in diagnosing chromosomal structural abnormalities is limited.In this article,we report a confusing QF-PCR finding in a pregnant woman who underwent amniocentesis.CASE SUMMARY The short tandem repeat marker AMXY(Xp22.2/Yp11.2)located on the sex chromosome exhibited a trisomic biallelic pattern,indicating that the karyotype of the fetus might be 47,XYY.Chromosome analysis performed on cultured amniocytes showed a normal male karyotype of the fetus.Copy number variation sequencing confirmed a 500 kb duplication at Yp11.2-Yp11.2(chrY:6610001_7110000)and a 250 kb duplication at Yp11.2-Yp11.2(chrY:7110001_7360000).CONCLUSION In conclusion,the comprehensive application of different methods could achieve a higher detection rate and accuracy for the prenatal diagnosis of chromosomal disorders through chromosomal testing.

Prenatal ultrasound diagnosis of congenital infantile fibrosarcoma and congenital hemangioma: Three case reports

BACKGROUND Congenital infantile fibrosarcoma(CIF)and congenital hemangioma(CH)have similarities on prenatal ultrasound and are rare.CASE SUMMARY We report 3 cases of fetuses with superficial hypervascular tumors,confirmed by postnatal pathology as CIF(1 case)and CH(2 cases,including 1 in a twin fetus).In Case 1,a mass with a rich blood supply in the fetal axilla was discovered by prenatal ultrasound at 28+0 wk of gestation.The postpartum pathological diagnosis was CIF,the mass was surgically removed,and the prognosis of the child was good.In Case 2,at 23+1 wk of gestation,a mass was discovered at the base of the fetus’s thigh on prenatal ultrasound.The postpartum pathological diagnosis was CH.After conservative treatment,the mass shrank significantly.Case 3 occurred in a twin fetus.At 30+0 wk of gestation,prenatal ultrasound revealed a bulging mass with a rich blood supply on the abdominal wall of one of the fetuses.Three weeks later,the affected fetus died,and the unaffected baby was successfully delivered by emergency cesarean section.The affected fetus was pathologically diagnosed with CH.CONCLUSION Prenatal ultrasound can provide accurate information,such as the location,size and blood supply of a surface mass in a fetus.We found similarities between CIF and CH in prenatal ultrasound findings.Although it is difficult to distinguish these conditions by prenatal ultrasound alone,for superficial hypervascular tumors that rapidly increase in size in a short period,close ultrasound monitoring of the fetus is required to quickly address possible adverse outcomes.

The effect of risk perception and COVID‑19 anxiety in pregnancy on decision‑making via the Internet and prenatal care quality:A cross‑sectional multivariate analysis

Background:Risk perception and COVID‑19 anxiety in pregnant women restrict access to health services,cause pregnant women to resort to alternative channels such as the Internet,and affect prenatal care quality(PCQ)negatively.Purpose:The purpose of this study was to examine the effect of risk perception and COVID‑19 anxiety in pregnancy on decision‑making via the Internet(DMI)and PCQ with multivariate analysis.Materials and Methods:This cross‑sectional study was conducted with 406 pregnant women selected using the convenience sampling method in a training and research hospital,in Turkey.The data were collected using the information form,the perception of pregnancy risk questionnaire,the Coronavirus Anxiety Scale,the DMI Scale,and the PCQ Scale.The data obtained were subject to descriptive analysis and the multivariate analysis of variance.Results:Approximately 24.9%of the pregnant women were found to have a high perception of risk and 18%had symptoms of COVID‑19 anxiety.Pregnant women with high COVID‑19 anxiety and a higher perception of risk perceived the Internet as less influential for decision‑making(P<0.05).Pregnant women with a high‑risk perception had lower PCQ(P<0.05).Conclusion:The findings can be used to enhance mental health and resilience in pregnant women and to formulate appropriate intervention strategies.

Prenatal radiographic evaluation of congenital transverse limb deficiencies:A scoping review

BACKGROUND Congenital transverse deficiencies are horizontal deficiencies of the long bones that occur with a reported incidence as high 0.38%.They can occur alone or represent a manifestation of a various clinical syndromes.Diagnosis has tradi-tionally comprised of conventional radiography and prenatal imaging studies.There has been much advancement regarding prenatal imaging modalities to allow for early diagnosis and appropriate treatment.AIM To summarize the current state of knowledge on congenital transverse limb deficiencies and to provide an update regarding the radiographic evaluation of congenital transverse limb deficiencies.METHODS This IRB-exempt scoping review followed the PRISMA-ScR checklist for scoping reviews strictly.Five search engines were searched for a total of 265 publications.Four authors reviewed these during the screening process.Of these,51 studies were included in our article.Prenatal magnetic resonance imaging(MRI),3D Ultrasound,and multidetector Computed tomography(CT)exist are emerging modalities that have the potential to improve diagnosis.RESULTS Use of the appropriate classification system,three-dimensional ultrasonography with a maximum intensity projection,and appropriate use of prenatal MRI and prenatal CT can improve diagnosis and inter-provider communication.CONCLUSION Further scholarly efforts are required to develop improve standardized guidelines regarding the pre-natal radiographic evaluation of congenital limb deficiencies.

Determinants of the Frequency of Prenatal Consultations among Women Giving Birth in the Maternity Wards of the Commune of Agbangnizoun (Zou), Benin

Antenatal care is a safe way to prevent pregnancy-related health problems, difficult deliveries and even further to anticipate low birth weight [1]. But pregnant women, especially in Africa, do not attend antenatal clinics as recommended by the WHO. The general objective of this study was to study the norm in terms of Antenatal Consultation (ANC) frequency as well as the determinants of the frequency among women who gave birth in the maternity hospitals of Agbangnizoun. Our research was a cross-sectional, descriptive, retrospective and quantitative type, which was carried out among 335 women in Agbangnizoun, Benin from 1 February to 3 April 2020 (3 months), in order to find out the general or specific characteristics of women that we associate with the frequency of prenatal consultation. At the end of the study, we found that 60%, 68% and 15% of the surveyed population had received ANC in the first, second and third trimesters, respectively. Ethnicity, income level of spouses over the three trimesters as well as the level of their knowledge and overall practice of ANC are determinants of the frequency of prenatal consultation.

Prenatal Diagnosis and Management of Fetal Goiter Treated Successfully with Intra-Amniotic Levothyroxine

Goiter is an enlargement of the thyroid gland which can be associated with a number of complications both for the mother and the fetus. A 34-year-old pregnant woman with normal thyroid function was referred to our Department of Obstetrics and Gynecology at Microcitemico Pediatric Hospital, Cagliari, for suspected fetal goiter at 32 gestational weeks. The case was monitored regularly by ultrasound and treated successfully with intra-amniotic levothyroxine (L-T4) administration. Fetal goiter was observed to decrease after this treatment and the thyroid ultrasound findings were also normal both at birth and in subsequent follow-ups. Our case report confirms the feasibility of conservative treatment with L-T4, which can effectively prevent complications related to fetal goiter.

Prenatal diagnosis of congenital fetal heart abnormalities and clinical analysis

Objective: To study the value of detecting fetal congenital heart disease (CHD) using the five transverse planes technique of fetal echocardiography. Methods: Nine hundred and eighty-two high-risk pregnancies for fetal CHD were included in this study, the fetal heart was scanned with the five transverse planes technique of fetal echocardiography described by Yagel, autopsy was conducted when pregnancy was terminated. Blood from fetal heart was collected for fetal chromosome analysis. A close follow-up was given for normal fetal heart pregnancies and neonatal echocardiography was performed to check the accuracy of prenatal diagnosis. Results: (1) Forty-six cases (4.68%) were found to have fetal heart abnormalities in this study, 69.56% of them were diagnosed by single four-chamber view, another 30.43% fetal CHD were found by combining other views; (2) Forty-one parents of prenatal fetuses with CHD chose to terminate pregnancy, thirty-two of them gave consent to conduct autopsy, 93.75% of which yielded unanimous conclusion between prenatal fetal echocardiography and autopsy; (3) Thirty-two of 46 cases underwent fetal chromosome analysis, 8 cases (25%) were found to have abnormal chromosome; (4) Five cases were found to have right ventricle and atrium a little bigger than those on the left side, with the unequal condition being the same after birth, but there were no clinical manifestations and they are healthy for the time being; (5) Nine hundred and thirty-six cases were not found with abnormality in this study, but one case was diagnosed with ventricular septal defect after birth, one case was diagnosed with patent ductus arteriosus, one case had atrial septal defect after birth. Conclusions: (1) The detected CHD rate was 4.68% by screening fetal heart with five transverse planes according to Yagel’s description of high risk population basis for CHD. The coinciding rate of prenatal diagnosis and autopsy was 93.75%; (2) The sensitivity of detecting fetal heart abnormality is 92%, the specificity is 99.6% using the five transverse planes technique of fetal echocardiography; (3) Fetuses with mild or moderate disproportion of right and left side in the heart are potentially healthy babies.

Validity of Different Methods to Prenatal Screening for Down’s Syndrom During First and Second Trimester Pregnancy of Chinese Women

Objective To identify and determine the optimal method to screening for fetal Down＇s syndrome （DS）. Methods Three large cohorts with 17 118, 39 903, 16 646 subjects were enrolled for the first trimester double marker （pregnancy-associated plasma protein A and free [B-human chorionic gonadotropin） screening （FTDMS）, second trimester double marker （c{-fetoprotein and free B-human chorionic gonadotropin） screening （STDMS）, and second trimester triple marker （a-fetoprotein, free 13-human chorionic gonadotropin and unconjugated estriol 3） screening （STTMS）, respectively. The sensitivity, specificity, false positive rate （FPR）, false negative rate （FNR） and the areas under ROC curves （AUCs） were estimated in order to determine the optimal screening method in women under or above 35 years old. Results For women under 35 years old, STTMS was the best method with a detection rate of 68.8% and FPR of 4.3% followed by the STDMS with a detection rate （sensitivity） of 66.7% and FPR of 4.9%. The FTDMS had a lower detection rate of 61.1% and FPR of 6.3%. For women above 35 years old, the detection rate of all the methods was similar, but STTMS method had a lowest FPR of 15.9%. For women under 35 years old AUCs were 0.77 （95% CI, 0.64 to 0.91）, 0.81 （95% CI, 0.71 to 0.91）, and 0.82 （95% CI, 0.69 to 0.96） for FTDMS, STDMS, and STTMS methods, respectively; for those above 35 years old, AUCs were 0.70 （95% CI, 0.56 to 0.83）, 0.70 （95% CI, 0.59 to 0.82）, 0.78 （95% Cl, 0.58 to 0.97） for FTDMS, STDMS and SITMS, respectively. Conclusion Findings from our study revealed that STDMS is optimal for the detection of fetal DS in pregnant women aged under 35. For individual women, if economic condition permits, STFMS is the best choice, while for women aged above 35, STTMS is the best choice in this regard.

Prenatal diagnosis and assessment of congenital spinal anomalies: Review for prenatal counseling

The last two decades have seen continuous advances in prenatal ultrasonography and in utero magnetic resonance imaging. These technologies have increasingly enabled the identification of various spinal pathologies during early stages of gestation. The purpose of this paper is to review the range of fetal spine anomalies and their management, with the goal of improving the clinician's ability to counsel expectant parents prenatally.

Non-invasive Prenatal Diagnosis of Trisomy 21 by Dosage Ratio of Fetal Chromosome-specific Epigenetic Markers in Maternal Plasma

This study examined the methylation difference in AIRE and RASSF1A between maternal and placental DNA, and the implication of this difference in the identification of free fetal DNA in maternal plasma and in prenatal diagnosis of trisomy 21. Maternal plasma samples were collected from 388 singleton pregnancies, and placental or chorionic villus tissues from 112 of them. Methylation-specific PCR （MSP） and methylation-sensitive restriction enzyme digestion followed by fluorescent quantitative PCR （MSRE ＋ PCR） were employed to detect the maternal-fetal methylation difference in AIRE and RASSF1A. Diagnosis of trisomy 21 was established according to the ratio of fetal-specific AIRE to RASSF1A in maternal plasma. Both methods confirmed that AIRE and RASSF1A were hypomethylated in maternal blood cells but hypermethylated in placental or chorionic villus tissues. Moreover, the differential methylation for each locus could be seen during the whole pregnant period. The positive rates of fetal AIRE and RASSF1A in maternal plasma were found to be 78.1% and 82.1% by MSP and 94.8% and 96.9% by MSRE ＋ PCR. MSRE ＋ PCR was superior to MSP in the identification of fetal-specific hypermethylated sequences （P〈0.05）. Based on the data from 266 euploidy pregnancies, the 95% reference interval of the fetal AIRE/RASSF1A ratio in maternal plasma was 0.33-1.77, which was taken as the reference value for determining the numbers of fetal chromosome 21 in 102 pregnancies. The accu-racy rate in 98 euploidy pregnancies was 96.9% （95/98）. Three of the four trisomy 21 pregnancies were confirmed with this method. It was concluded that hypermethylated AIRE and RASSF1A may serve as fetal-specific markers for the identification of fetal DNA in maternal plasma and may be used for noninvasive prenatal diagnosis of trisomy 21.