Fetal nasal bone hypoplasia in the second trimester: Comparison of diagnostic methods for predicting trisomy 21 (Down syndrome).

PURPOSE: The aim of this prospective observational study was to identify the best method for use in diagnosing fetal nasal bone (NB) hypoplasia in the second trimester as a means of predicting trisomy 21 (Down syndrome). METHODS: The NB length (NBL), NBL percentiles, and NBL multiple-of-median (MoM) values and the biparietal diameter-to-NBL ratios were calculated and compared in an attempt to identify the best predictive method and most appropriate cutoff value. Predictive values for several cutoff points were calculated. Receiver operating characteristic curves at a fixed 5% false-positive rate were used to compare the four methods. RESULTS: NBL measurements were obtained from 2,211 (95.6%) of a total of 2,314 fetuses. Data from 1,689 of those 2,211 fetuses were used to obtain reference ranges, derive a linear regression equation, and calculate NBL percentiles and MoM values. Using a fixed 5% false-positive rate, we found 25.5% sensitivity for NBL (95% confidence interval [CI], 15-39.1) and 23.5% sensitivity for NBL percentiles (95% CI, 13.4-37), NBL MoM values (95% CI, 13.4-37), and biparietal diameter-to-NBL ratios (95% CI, 13.4-37). CONCLUSIONS: Our study demonstrated that all four methods can be used in the second trimester for diagnosing fetal NB hypoplasia as a means of predicting trisomy 21 because their predictive values are similar at a fixed 5% false-positive rate. For simplicity of use, we recommend using 3 mm as the NBL cutoff value.

Bipolar cord coagulation in the management of complicated monochorionic twin pregnancies.

AIM: To report our experience in selective termination of monochorionic twin pregnancies with bipolar cord coagulation and to analyze the pregnancy outcomes and complications based on the indication of the procedure. METHODS: This is a retrospective study of 71 complicated monochorionic pregnancies treated with bipolar cord coagulation between August 2006 and March 2013. RESULTS: The rates of live birth and survival up to 28 days after birth were 73.2% (52/71) and 63.4% (45/71), respectively. The highest rates of survival up to 28 days after birth were in the procedures with an indication of selective intrauterine growth restriction, while the lowest rates of survival were recorded with the indication of twin reversed arterial perfusion sequence and discordant anomaly. However, there were no statistically significant differences in the live birth and perinatal survival rates among the four different groups of indications. CONCLUSION: The survival rate of bipolar cord coagulation in complicated monochorionic pregnancies such as twin-to-twin transfusion syndrome, twin reversed arterial perfusion sequence, selective intrauterine growth restriction and discordant anomaly was 63% in our series.

Stage-related outcome after fetoscopic laser ablation in twin-to-twin transfusion syndrome.

AIM: To review the perinatal outcome of twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser coagulation in a developing country with detailed analysis according to the stage of the syndrome. METHODS: This was a retrospective study of 85 TTTS cases treated with fetoscopic laser coagulation at the Fetal Diagnosis and Treatment Unit of Istanbul Faculty of Medicine between January 2006 and March 2013. RESULTS: The surgical failure rate was 5.8% (5/85). Among all the cases of the total cohort, only 1 fetus survived in 27 pregnancies (31.8%), and both fetuses survived in 22 pregnancies (25.9%). In 49 pregnancies (57.6%) at least one fetus survived at the end of the neonatal period. The overall survival and live birth rates were 41.8% (71/170) and 56.4% (96/170), respectively, and they significantly decreased as the stage of disease increased. Delivery occurred before 32 weeks of gestation in 54 (63.5%) pregnancies. Logistic regression analysis showed that gestational age at delivery was the only independent factor, and the risk of nonsurvival significantly decreased with increasing age. CONCLUSION: Based on our experience, the outcome of fetoscopic laser coagulation of the placental anastomoses for TTTS became worse as the Quintero stage of the disease advanced.

Current approaches on non-invasive prenatal diagnosis: Prenatal genomics, transcriptomics, personalized fetal diagnosis.

Recent developments in molecular genetics improved our knowledge on fetal genome and physiology. Novel scientific innovations in prenatal diagnosis have accelerated in the last decade changing our vision immensely. Data obtained from fetal genomic studies brought new insights to fetal medicine and by the advances in fetal DNA and RNA sequencing technology novel treatment strategies has evolved. Non-invasive prenatal diagnosis found ground in genetics and the results are widely studied in scientific arena. When Lo and colleges proved fetal genetic material can be extracted from maternal plasma and fetal DNA can be isolated from maternal serum, the gate to many exciting discoveries was open. Microarray technology and advances in sequencing helped fetal diagnosis as well as other areas of medicine. Today it is a very crucial prerequisite for physicians practicing prenatal diagnosis to have a profound knowledge in genetics. Prevailing practical use and application of fetal genomic tests in maternal and fetal medicine mandates obstetricians to update their knowledge in genetics. The purpose of this review is to assist physicians to understand and update their knowledge in fetal genetic testing from maternal blood, individualized prenatal counseling and advancements on the subject by sharing our experiences as Istanbul University Fetal Nucleic Acid Research Group.

Comparison of real-time polymerase chain reaction assay methods for detection of RHD gene in amniotic fluid.

Hemolytic disease of the newborn is the clinical condition in which Rh blood group antigens in couples are incompatible with each other and mother is negative for the antigen, whereas father is positive. Although RHD antigen encoded by RHD gene that is localized on chromosome 1 determines person's Rh genotyping, this incompatibility can lead to delivery as anemia, jaundiced, or dead in mother's uterus. In recent years, improvements have occurred in the prenatal diagnosis of Rh incompatibility. Quantitative real-time polymerase chain reaction (Real-time PCR) has been improved and determining rapidly, reliably, and sensitively has been possible. In this study, the determination of RHD genotyping was investigated using fetal DNA obtained from amniotic fluid and SYBR Green I and TaqMan probe methods were compared, and reliability in prenatal diagnosis of these methods was determined. We studied 35 pregnant women in the second trimester of pregnancy. "SYBR Green I" and "TaqMan" probes results for RHD gene of genomic DNA extracted from total 35 different amniotic fluid samples acquired from 10 RHD (-) and 25 pregnant women randomly were analyzed. DNA extracted from amniotic fluid was analyzed for RHD gene with real-time PCR and the results were then compared with the RHD fetal genotype determined on RHD phenotype of the red blood cells of the infants at birth. The results of RHD TaqMan probes PCR analysis of amniotic fluid DNA were completely concordant with the fetal blood group analysis after birth. Real-time PCR using the TaqMan probes has proven to be more sensitive, accurate, and specific for RHD gene than SYBR Green I method.

Detection of fetal RhD gene from maternal blood.

OBJECTIVE: Hemolytic disease of the newborn (HDN) is a clinic phenomenon which occurs during pregnancy due to the Rhesus (Rh) D alloimmunization between a Rh (-) pregnant woman, who has become sensitive to RhD antigens, and her Rh (+) fetus. As a result of the attack of maternal RhD antibodies on fetal RhD antigens, fetal anemia, HDN and fetal death may occur. % 40 of Rh (-) pregnant women carry Rh (-) fetus. However, all Rh (-) pregnant women are offered anti-D Immunoglobulin (Anti-D Ig) at 28 weeks' gestation in case of fetomaternal haemorrhage, so the pregnant women carrying Rh (-) fetus are exposed to blood products unnecessarily. Although the RhD of fetus can be detected, methods used for prenatal diagnosis recently are invasive tests and they can result in abortion in a certain percentage. The discovery of circulating cell-free fetal nucleic acids in maternal plasma has opened up new possibilities for non invasive prenatal diagnosis. The aim of this study was to detect prenatal RhD by analysing the presence of the RhD gene of fetal DNA in maternal blood. MATERIAL AND METHODS: Total free DNA was isolated from the blood of 19 Rh (-) pregnant women, who had RhD alloimmunization with their husbands, in the 11-14 th week of their pregnancy. The existence of a gene in isolated DNA was investigated with TaqMan prob and "Real-time PCR" method by using primers belonging to exon 7 of RhD gene. RESULTS: Using a quantitative real-time PCR assay, the presence of RhD gene sequences was evaluated in the serum of patients at the onset of pregnancy. We have analyzed 19 Rh (-) pregnant women. Twelve of them were Rh (-) and the rest of them were 7 Rh (+). After birth the baby's blood groups were concordant with our results. CONCLUSION: The results obtained by RhD primer were analysed. The possibility of detection of fetal RhD gene in maternal blood contributed to noninvasive prenatal diagnosis.

Fetal nasal bone assessment in first trimester down syndrome screening.

OBJECTIVE: To evaluate the contribution of nasal bone assessment in the first trimester Down syndrome screening. METHODS: The fetuses which underwent first trimester screening with nuchal translucency (NT) measurement were evaluated for the absence or presence of nasal bone according to the instructions described by the Fetal Medicine Foundation, London. RESULTS: Among the 1,807 fetuses included in the study, 9 had trisomy 21. The detection rate of Down syndrome with NT measurement was 77.8% (7/9) with a false-positive rate of 4.5%. Incorporation of biochemical tests (PAPP-A, and free beta-hCG measurement) into the screening increased the detection rate to 88.9% (8/9) and decreased the false-positive rate to 3.6%. The prevalence of absent nasal bone was 7/1,798 (0.39%) in chromosomally normal fetuses, and 3/9 (33.3%) in Down syndrome fetuses. Sensitivity, specificity, positive predictive and negative predictive values of absence of nasal bone for trisomy 21 are 33.3% (CI: 0.12-0.64), 99.6% (CI: 0.99-0.99), 30% (95% CI: 0.11-0.53) and 99.7% (95% CI: 0.99-0.99), respectively. The positive likelihood ratio of absent nasal bone was 85.6 (95% CI: 26.2-279.5), and the negative likelihood was 0.67 (95% CI: 0.42-1.06). When nasal bone assessment was incorporated into the NT risk assessment or combined test, the detection rate of trisomy 21 was not changed, however, the false-positive rate decreased to 3.4 and 3%, respectively. CONCLUSION: The absence of fetal nasal bone has a high positive likelihood ratio for Down syndrome in the first trimester screening, and the presence of nasal bone may potentially lower the need for invasive testing.

Screening for fetal chromosomal abnormalities with nuchal translucency measurement in the first trimester.

OBJECTIVE: To describe the detection rate of first-trimester chromosomal abnormality screening with nuchal translucency (NT) measurement and maternal age in our population. METHODS: We have screened the fetuses between 11 to 14 weeks' gestation according to the Fetal Medicine Foundation's (London) instructions and used the FMF's software to assess the risk based on maternal age, crown-rump length (CRL) and NT. Fetal karyotyping was offered when screening for Down syndrome identified a risk greater than 1 in 300. Sensitivity and false-positive rates were calculated for different cut-offs. RESULTS: Pregnancy outcome was obtained from 4,598 babies of 4,365 mothers. The median maternal age of the 4,365 women was 28.2+/-5.3 (range 15-47) years, and the median fetal CRL was 65.4+/-9.4 (range 45-81) mm. There was risk estimate of >or=1 in 300 in 214 fetuses (4.7%). Chromosomal abnormalities were identified in 32 fetuses, including 19 cases of trisomy 21, and 13 cases of other abnormalities. The sensitivity using NT and maternal age in detecting trisomy 21 with a cut-off 1 in 300 was 73.6% (14/19) with a false-positive rate of 4.7%. At a false-positive rate of 3%, with a cut-off level 1 in 210, the detection rate was 73.6%. The detection rate for all chromosomal abnormalities with a cut-off level 1 in 300 was 68.8% (22/32) at a false-positive rate of 4.7%. CONCLUSION: The first-trimester screening for chromosomal anomalies with NT measurement, when carried out according to the accepted standards of quality, is useful.

Therapeutic amniocentesis for treatment of twin-twin transfusion syndrome.

OBJECTIVE: The objective was to determine whether therapeutic amniocentesis may improve outcomes in patients with twin-twin transfusion syndrome. STUDY DESIGN: Eleven patients were managed aggressively with repetitive serial amniocenteses, and six patients were managed conservatively. RESULTS: The time interval between diagnosis and delivery was 17.4 days more in the amniodrainage group, but the difference between the groups was not significant (68.3+/-41.9 days in the therapeutic amniocentesis group and 50.83+/-29.7 days in the expectant management group [p=0.384]). The overall survival rate of the two groups was 38.2%, and was not significantly different between groups (40.9% in the amniocentesis group and 33.3% in the expectant management group; p=1.00). Two of nine (22.2%) infants in the amnioreduction group, and one of four (25.0%) infants in the expectantly managed group had neurological symptoms. CONCLUSION: Our results did not show a significant benefit of aggressive therapeutic amniocentesis. A slight improvement in perinatal outcome was observed.

Dandy-Walker malformation: a review of 78 cases diagnosed by prenatal sonography.

OBJECTIVE: The purpose of this study was to determine the associated abnormalities and clinical outcomes of fetuses with Dandy-Walker malformations. METHODS: Sonograms and medical reports of 78 cases were reviewed and information regarding each outcome was collected from autopsy records, hospital charts and specialists caring for the surviving infants. RESULTS: We identified 64 fetuses with classic Dandy-Walker malformation (DW) and 14 fetuses with Dandy-Walker variant (DWV). A high proportion (44.8%) of the parents were consanguineous. The spectrum and proportion of central nervous system (67.1 vs. 71.4%; p = 1.0) and other malformations (43.7 vs. 64.2%; p = 0.57) associated with DW and DWV were similar. Chromosome abnormalities were found in 9 of the 51 (17.6%) fetuses that underwent karyotype analysis. Only 4 of 64 (6.2%) DW and 3 of 14 (21.4%) DWV infants survived (p 0.14), and all surviving infants with DW or DWV had neurological disorders. CONCLUSIONS: DW and DWV cases show so many similarities that a clear-cut distinction is difficult. There was no significant difference in the spectrum of associated anomalies and postnatal prognosis between DW and DWV cases.

Prenatal diagnosis of Wolf-Hirschhorn syndrome (4p-) in association with congenital hypospadias and foot deformity.

BACKGROUND: Wolf-Hirschhorn syndrome is caused by distal deletion of the short arm of chromosome 4 (4p-). We report a case in which intrauterine growth restriction, hypospadias and foot deformity were detected by prenatal ultrasound examination at 29 weeks of gestation. CASE PRESENTATION: A 31-year-old gravida 2 partus 1 woman was referred at 29 weeks' gestation with suspicion of intrauterine growth restriction. Sonographic examination revealed deformity of the right lower limb and undescended testes with an irregular distal penis. A cordocentesis was performed and chromosome analysis revealed a 46,XY,del(4)(p14) karyotype. CONCLUSION: The prenatal detection of intrauterine growth restriction, hypospadias and foot deformity should lead doctors to suspect the presence of Wolf-Hirschhorn syndrome.

Partial molar appearance of the placenta in trisomy 13.

Although molecular studies have shown that more than 90% of partial moles are secondary to diandric triploidy, there are some rare cases with tetraploidy or unspecified aneuploidies. We diagnosed 3 cases of partial mole presentation during the 2nd trimester of pregnancy with multiple fetal abnormalities. In all 3 cases, cytogenetic studies showed trisomy 13. We present the cases and discuss the clinical and pathological aspects of the conditions presented as partial moles.

Comparison of 25 and 50 microg vaginally administered misoprostol for preinduction of cervical ripening and labor induction.

Our purpose was to compare the efficacy of 25 microg and 50 microg intravaginally administered misoprostol tablets for cervical ripening and labor induction. Either 25-microg (n: 58) or 50-microg (n: 56) misoprostol tablets were randomly administered intravaginally to 114 subjects with an unripe cervix for labor induction. The physician was blinded to the medication. Intravaginal misoprostol was given every 4 h until the onset of labor. The mean Bishop score before misoprostol administration was 2.1 +/- 1.6 in the 25-microg group and 2.0 +/- 1.4 in the 50-microg group (p > 0.05). With the 25-microg dose the time until delivery was significantly longer (991.2 +/- 514.4 min vs. 703.12 +/- 432.6 min in the 50-microg group). The use of oxytocin augmentation was significantly higher in the 25-microg group (63.8%) than the 50-microg group (32.1%; p < 0.05). The proportions of patients with tachysystoles and hypersystoles were not significantly different between the two groups (19 and 6.9%, respectively, in the 25-microg group and 25 and 17.8%, respectively, in 50-microg group; p > 0.05). Overall, in the 25-microg group more women achieved vaginal delivery (79.3 vs. 60.7%; p < 0.05). The rate of cesarean sections due to non-reassuring fetal status was higher in the 50-microg misoprostol group (28.6 vs. 10.3%; p < 0.05). The number of neonates with a low 1-min Apgar score (<7) was significantly higher in the 50-microg misoprostol group (26.8 vs. 8.6%; p < 0.05), but 5-min Apgar scores and umbilical artery blood gas values at the time of delivery were not significantly different between the groups (p > 0.05). One patient in the 25-microg group suffered a ruptured uterus. Intravaginal administration of 25 microg of misoprostol is a clinically effective labor induction regimen and has the least adverse effects and complications.