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.

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.

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.

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.

Transient gestational diabetes insipidus diagnosed in successive pregnancies: review of pathophysiology, diagnosis, treatment, and management of delivery.

Gestational diabetes insipidus (GDI) is a rare disorder characterised by polyuria, polydypsia, and excessive thirst usually manifesting in the third trimester of pregnancy. The etiology is thought to depend on excessive vasopressinase activity, a placental enzyme that degrades arginine-vasopressin (AVP), but not 1-deamino-8-D: -arginine vasopressin (dDAVP), which is a synthetic form. This is a transient syndrome and may be associated with acute fatty liver of pregnancy and preeclampsia. The use of dDAVP in symptomatic cases has been proven as a safe method for both the mother and the fetus during the pregnancy. We report a case of recurrent gestational diabetes insipidus in successive pregnancies, which responded to dDAVP and subsided after delivery.

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.

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.