Fetal gastroschisis: a comparison of second vs. third-trimester bowel dilatation for predicting bowel atresia and neonatal outcomes.

PURPOSE: To compare various gestational ages and thresholds for diagnosing bowel dilatation in fetuses with gastroschisis and to evaluate the prognostic value of bowel dilatation for predicting postnatal bowel atresia and neonatal outcomes. MATERIALS AND METHODS: This was a retrospective observational study conducted from March 1997 to September 2009 that included 78 pregnancies with fetal gastroschisis. The predictive value of prenatal bowel dilatation for neonatal bowel atresia and postnatal complications was investigated in three subgroups: those with bowel dilatations ≥ 10 mm at a gestational age < 27 + 0 weeks, ≥ 10 mm at a gestational age < 30 + 0 weeks and ≥ 18 mm at a gestational age ≥ 30 weeks. RESULTS: Prenatally, 6 %, 81 % and 13 % of the bowel malformations were identified in the first, second and third trimesters, respectively. There were three stillbirths and three neonatal deaths, and the mean gestational age at delivery was 35.4 weeks (range 31 + 4 to 41 + 6). Bowel atresia was significantly correlated with prenatal bowel dilatation in all three subgroups. Bowel dilatations of ≥ 10 mm before 30 + 0 gestational weeks achieved the best performance in predicting bowel atresia, with a sensitivity of 89 % (8 / 9) and a specificity of 79 % (30 / 38). A prenatal bowel diameter ≥ 10 mm through 30 completed weeks was also the best predictor of a prolonged neonatal hospital stay ≥ 8 weeks (sensitivity = 61.1, 11 / 18, p = 0.002). CONCLUSION: Fetuses with isolated gastroschisis successfully underwent postnatal surgery in most cases (93.2 %), except for one termination, one intrauterine death and 3 cases of neonatal death. A fetal bowel dilatation > 10 mm before 30 + 0 weeks had the highest predictive value for postnatal bowel complications.

Impact of maternal obesity and maternal overweight on the detection rate of fetal heart defects and the image quality of prenatal echocardiography.

PURPOSE: The purpose of this study was to compare the prenatal detection of four congenital heart defects (CHDs) and the image quality of five corresponding ultrasound planes among obese, overweight and normal-weight women. MATERIALS AND METHODS: This was a retrospective cohort study of 54,846 pregnancies undergoing fetal echocardiography between 18 and 37 weeks of gestation in the years from 2000 to 2007. The women were categorized according to pre-pregnancy body mass index (BMI) as normal-weight (BMI < 25), overweight (BMI 25 - 29.9) and obese (BMI ≥ 30). Image quality and prenatal detection of atrioventricular septal defect (AVSD), double outlet right ventricle (DORV), tetralogy of fallot (TOF) and dextro transposition of the great arteries (D-TGA) were evaluated in the BMI strata. RESULTS: 108 cases with one of the considered CHDs were identified. The prevalence was significantly higher (relative risk = 2.04) in overweight or obese women (57/19,404 vs. 51/35,442, p < 0.0002) than in normal-weight women. In total 86.1% of CHDs were correctly identified prenatally (93/108, CI: 79.6%-92.6%), 84.3% (43/51) in the normal weight group, 88.6% (39/44) in the overweight group and 84.6% (11/13) in the obese group. The rate of insufficient ultrasound images increased from 6.4% in normal-weight patients to 17.4% in obese women within the 108 CHD cases. CONCLUSION: The prenatal detection of fetal AVSD, DORV, TOF and D-TGA was also satisfactory in overweight and obese patients, but image quality substantially decreases with an increasing maternal BMI. If there is a BMI-associated difference in the detection rate, it probably will not exceed 20%.

Comparing first trimester screening performance: routine care gynaecologists' practices vs. prenatal centre.

OBJECTIVE: To evaluate and compare the screening performance for fetal trisomy 21 in the first trimester of pregnancy in general gynaecologists' practices and specialised centres for prenatal care in Germany. METHODS: This study included 15,026 serum samples analysed in our laboratory for free beta-human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks of gestation between 1.1.2000 and 31.12.2003. Fetal risk for trisomy 21 was calculated using nuchal translucency (NT) values and crown-rump-lengths (CRL), measured either in general gynaecologists' practices or in a tertiary level prenatal centre. The detection rate for a fixed risk cut-off (1:300) and a fixed false-positive rate (5 %) was calculated for NT, serum biochemistry, maternal age and the combination of these components. RESULTS: The estimated risk for trisomy 21 based on maternal age, fetal NT and maternal serum free beta-hCG and PAPP-A was 1 in 300 or greater in 5.1 % (362 of 6897) and 8 % (329 of 3840) of normal pregnancies, and in 78.9 % (15 of 19) and 88.5 % (23 of 26) of those with trisomy 21. For a fixed false-positive rate of 5 %, the respective detection rates of screening for fetal Down's syndrome by maternal age and serum free beta-hCG and PAAP-A, maternal age and fetal NT and by maternal age, fetal NT and maternal serum biochemistry were (general gynaecologists' practices/prenatal centre) 68.4/69.2 %, 42.1/65.4 % and 78.9/88.5 %, respectively. CONCLUSION: The screening results are satisfactory in both general gynaecologists' practices and a prenatal centre.

Additional performance of nasal bone in first trimester screening.

OBJECTIVE: To evaluate and compare the screening performance for fetal trisomy 21 in the first trimester of pregnancy either with or without inclusion of fetal nasal bone using two separate risk-algorithms of the Fetal Medicine Foundation London (FMF). METHODS: This study included 3174 patients self-referred to our tertiary level prenatal centre for first trimester screening at 11-14 weeks of gestation between December 1, 2002 and November 30, 2004. Fetal risk for trisomy 21 was calculated using either the old FMF-algorithm including maternal age, nuchal translucency (NT), free ss-human chorionic gonadotropin (hCG), pregnancy-associated plasma protein-A (PAPP-A) or the new FMF-algorithm using additionally the presence or absence of fetal nasal bone (NB). All ultrasonographers were certified for measurement of nuchal translucency and nasal bone by the Fetal Medicine Foundation Germany. The detection rate for a fixed risk cut-off (1:300) and a fixed false-positive rate (5 %) was calculated for ultrasound (single NT or NT and NB), serum biochemistry, maternal age and the combination of these components. RESULTS: Pregnancy outcome was obtained in 2973 (93.6 %) cases. Nasal bone was absent in 5 of 18 (27.8 %) cases with fetal trisomy 21 and in 2 of 2961 (0.1 %) normal cases. The estimated risks for trisomy 21 based on maternal age, fetal ultrasound and maternal serum free ss-hCG and PAPP-A was 1 in 300 or greater in (old algorithm without NB/new algorithm including NB) 5.5 % (179 of 2961) and 2.8 % (97 of 2961) normal pregnancies and in 94.4 % (17 of 18) and 77.8 % (14 of 18) of those with trisomy 21. For a fixed false-positive rate of 5 % the respective detection rates of screening for fetal Down's syndrome by maternal age and serum free ss-hCG and PAAP-A, maternal age and fetal ultrasound and by maternal age, fetal ultrasound and maternal serum biochemistry were (old algorithm without NB/new algorithm including NB) 72.2 %/66.7 %, 83.3 %/77.8 % and 88.9 %/83.3 %, respectively. CONCLUSION: Our data show no additional performance of including presence or absence of fetal nasal bone in calculation of risk for fetal Down's syndrome between 11 and 14 weeks of gestation. Individual risk-orientated two-stage screening could be an alternative approach for integration of additional ultrasound markers in first trimester screening.

Quantitative fluorescent polymerase chain reaction versus cytogenetics: risk-related indication and clinical implication of nondetected chromosomal disorders.

BACKGROUND: The rapid detection of aneuploidies by quantitative fluorescent polymerase chain reaction (QF-PCR) allows reliable prenatal diagnosis of trisomies 21, 18, and 13. Discussion has been raised as to whether single QF-PCR could be an alternative to traditional cytogenetic karyotyping for certain referral categories. OBJECTIVE: To evaluate an indication-based classification of cases at risk of missing clinically relevant chromosomal disorders by QF-PCR. METHODS: From October 1999 to November 2003, 4,682 of 14,123 patients referred for amniocentesis decided to have QF-PCR as a rapid adjunct to conventional cytogenetic evaluation. Patients were classified according to the risk of missing chromosomal abnormalities by QF-PCR based on anamnestic risk and ultrasound prior to amniocentesis. The results in these two defined categories were compared in relation to the clinical significance of cytogenetic results. RESULTS: QF-PCR and conventional cytogenetic analysis had concordant results in 4,617 of 4,682 (98.6%) cases. Thirty-six of 110 (32.2%) clinically significant chromosomal abnormalities were missed by QF-PCR. Patients classified not to be at risk of missing chromosomal abnormalities using QF-PCR had a residual risk of 1/166 (0.6%) for chromosomal distortions of clinical significance. CONCLUSION: Classification by anamnestic and sonographic data does not specifically identify patients at risk of structural abnormalities. Clinical relevance of the nondetected anomalies essentially justifies traditional karyotyping regardless of risk classification.