Biomedical subjects
Publications and source records attributed to R Achiron.
The occurrence of a triplet pregnancy discordant for anencephaly is rare and its management presents a clinical dilemma. We report what appears to be the first case of a triplet pregnancy with two anencephalic fetuses complicated by premature contractions and severe polyhydramnios. Its management, which results a healthy newborn weighing 1385 g is discussed.
OBJECTIVE: To establish reference ranges during human pregnancy for normal fetal corpus callosum dimensions. DESIGN: In a prospective, cross-sectional study of 258 fetuses between 16 and 37 weeks of gestation, measurements of the length, width, and thickness at the level of the anterior mid-body of the corpus callosum were performed, using high-resolution, transvaginal and transabdominal transducers. RESULTS: The mean length of the corpus callosum was 27.2 (standard deviation, 1.2; 95% confidence interval, 26.02-28.37) mm. Width and thickness of the corpus callosum were 5.6 (standard deviation, 1.6; 95% confidence interval, 5.41-5.82) mm and 1.9 (standard deviation, 0.7; 95% confidence interval, 1.87-2.06) mm, respectively. The size of the corpus callosum as a function of gestational age was expressed by regression equations: length (mm) = -20.40 + 1.92 x gestational age; width (mm) = -0.052 + 0.225 x gestational age; thickness (mm) = -0.174 + 0.085 x gestational age. The dimension-gestational age correlation coefficients were: r = 0.779 for length, r = 0.676 for width and r = 0.494 for thickness; these were statistically significant (P < 0.01). The maximum increase in thickness and width of the corpus callosum occurred between 19 and 21 weeks' gestation, while its length followed a constant growth rate. The normal mean length, width and thickness of the corpus callosum per week, and the 95% confidence limits, were defined. CONCLUSIONS: The present study offers normative measurements of the fetal corpus callosum and may facilitate a more objective diagnosis of its congenital abnormalities.
OBJECTIVE: To establish a nomogram for fetal penile length during gestation. DESIGN: A prospective, cross-sectional study of normal singleton pregnancies. SUBJECTS: Four hundred and nineteen male fetuses between 14 and 38 weeks were studied. METHODS: Measurements of fetal penis length were performed by high resolution transvaginal ultrasonography between 14 and 17 weeks of gestation, and by transabdominal ultrasonography beyond 18 weeks of gestation. RESULTS: Adequate penile length measurements were obtained in all 419 fetuses. Penile length as a function of gestational age was expressed by the regression equation: (square root) penile length (mm) = 0.277 + 0.121 x gestational age (weeks). The correlation coefficient, r = 0.967 was found to be highly statistically significant (P < 0.0001). The normal mean and the 90% prediction limits were defined. During the study period, we identified three fetuses with abnormalities involving penile development. Using the above reference data range, it has been shown that their penile length was below the lower limit. CONCLUSIONS: The present data provide a normal range of fetal penile length from early stages of gestation that may allow intrauterine assessment of the development of the male external genitalia.
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OBJECTIVES: To compare the outcome of multifetal pregnancy reduction from triplets to twins performed either early (at 11-12 weeks' gestation) or late (at 13-14 weeks). METHODS: Ninety-five high-order pregnancies following assisted conception were studied. Transabdominal sonographically guided multifetal pregnancy reduction was performed early in 46 women, while 49 women first underwent a sonographic fetal anomaly scan before undergoing selective reduction. RESULTS: Sonographic screening led to selective termination of a specific fetus in nine cases due to increased nuchal translucency and relative intrauterine growth restriction in three cases each, and meningomyelocele, abdominal cyst and cystic hygroma in one case each. In the early reduction group a diagnosis of hypoplastic left heart in the two remaining twins was subsequently made, and one pair of twins suffers from cerebral palsy. The rate of pregnancy loss was not statistically different between the early (4.3%; 2/46) and late (4.0%; 2/49) termination groups. The birth weight and gestational age at birth were not statistically different between the early ( n = 85) and late ( n = 94) groups (2110 +/- 580 vs. 2140 +/- 490 g, and 35.8 +/- 3.0 vs. 35.7 +/- 3.5 weeks). Similarly there was no statistically significant difference between early and late groups in the incidence of very premature (24-32 weeks; 9.3 vs. 8.3%) and premature (33-36 weeks; 46.5 vs. 47.9%) births. CONCLUSIONS: Early second-trimester multifetal pregnancy reduction from triplets to twins may allow more selective termination of abnormal fetuses without an adverse effect on the outcome of pregnancy. However, further studies are needed in order to confirm our observations in a larger series.
OBJECTIVE: To investigate whether ultrasonography is superior to vaginal examination for determination of fetal occiput position during the second stage of labor. METHODS: We conducted a prospective cohort study of 44 parturients. During the second stage of labor, an attending obstetrician performed a vaginal examination to detect fetal occiput position. This was followed by combined abdominal and perineal ultrasound examination. The two methods were compared to the true position. Results were analyzed using Student's t test for quantitative parameters. McNemar's and Fisher's exact tests were applied in order to examine differences between the study groups. RESULTS: The error rate in detecting fetal occiput position was significantly lower using the ultrasound technique (6.8%) compared to vaginal examination (29.6%, p = 0.011). Parity, maternal body mass index or fetal weight had no influence on the error rate. CONCLUSIONS: Ultrasonographic determination of the fetal position is an accurate technique and is superior to vaginal examination.
BACKGROUND: Slight morphological asymmetry of the cerebral hemispheres has been observed in fetal and newborn brains. In adults, sex differences in hemispheric asymmetry have also been reported. OBJECTIVE: To establish whether cerebral hemisphere asymmetry correlates with sex in fetuses. METHODS: Left-right cerebral hemisphere asymmetry, and the correlation with sex, were studied in 51 male and 51 female fetuses of 20-22 weeks gestation, using diagnostic ultrasound scanning. RESULTS: A total of 102 fetuses were examined. The diameter of the left hemisphere was larger than that of the right, in both female and male fetuses. The mean (SEM) diameter of the left hemisphere was 2.804 (0.174) cm in female fetuses and 2.781 (0.287) cm in male fetuses; the corresponding values for the right hemisphere were 2.627 (0.192) cm and 2.681 (0.267) cm. There was no sex related difference between hemispheric diameters. The interhemispheric difference was significant for both sexes: male fetuses, p = 0.017; female fetuses, p = 0.016. CONCLUSIONS: Left-right fetal brain asymmetry, as measured by in utero ultrasound examination, is apparent at 20-22 weeks gestation regardless of sex.
OBJECTIVE: To assess the efficacy, safety, and associated complications of sonohysterography for the diagnosis of residual trophoblastic tissue. METHODS: We conducted a prospective study of 23 consecutive patients admitted to our ultrasonography unit with clinical and ultrasonographic signs of retained intrauterine tissue. RESULTS: Twelve patients had hydrosonographic features suggestive of residual trophoblastic tissue (i.e., an intrauterine lesion not detachable from the uterine wall after instillation of saline), whereas in 11 cases the hydrosonographic findings were negative for retained tissue. Blood flow was detected within abnormal intrauterine masses in 4 of 12 patients with trophoblastic tissue, whereas it was not detected in any patient without retained tissue (P = .093). No complications were encountered during the procedure or the postprocedure period. None of the patients had anesthetic complications, perforation of the uterus, fluid overload, or any other surgical complication. All 12 patients underwent hysteroscopic removal of the suspected residual trophoblastic tissue, and histologic confirmation of residual trophoblastic tissue was obtained in all cases. CONCLUSIONS: Sonohysterography for detection and diagnosis of residual trophoblastic tissue is an accurate and safe procedure. Further studies comparing the efficacy of sonohysterography with that of diagnostic hysteroscopy are warranted.
A cross-sectional study of pregnant women presenting for routine fetal ultrasonographic examination was conducted at the Obstetric Ultrasonographic Unit of the Chaim Sheba Medical Center to investigate in utero development of the fetal corpus callosum (CC) in relation to fetal gender. A total of 255 consecutive healthy fetuses of low-risk pregnancies between 16 and 36 weeks' gestation were examined. Thickness and width of the anterior mid-body of the CC were measured in the mid-coronal plane, and length was measured in the mid-sagittal plane. Fetal gender was determined by an independent observer. Female fetuses had statistically significantly thicker CC than males for each gestational age. The mean +/- standard deviation (SD) CC thickness in females was 2.13 +/- 0.8 mm [95% confidence interval (CI) 1.98-2.28] while the mean +/- SD CC thickness in males was 1.8 +/- 0.5 mm (95% CI 1.70-1.89; p < 0.01). The length and width of the CC during gestation did not differ significantly between the sexes. Corpus callosum size as a function of gestational age (GA) in both sexes was expressed by linear regression equations. The correlation coefficients r = 0.93, r = 0.61 and r = 0.62 for length, width and thickness, respectively, in males and r = 0.92, r = 0.71 and r = 0.72 in females were found to be statistically significant (p < 0.01). The present data suggest that female fetuses have a thicker CC than males. These findings support previous studies suggesting sex dimorphism of human CC and raise the possibility that prenatal sex hormones may play a role in determining callosal development.
Noonan syndrome is one of the most common of genetic syndromes and manifests at birth, yet it is usually diagnosed during childhood. Although prenatal diagnosis of Noonan syndrome is usually not possible, in a few cases the ultrasonographic findings suggested the diagnosis in utero. Reported sonographic clues include septated cystic hygroma, hydrothorax, polyhydramnios, and cardiac defects, such as pulmonic stenosis and hypertrophic cardiomyopathy. During a 6-year period, 46,224 live-born infants were delivered at the Chaim Sheba Medical Center. Seven newborn infants and four fetuses were found to have Noonan syndrome. One fetus showed transient nuchal translucency of 4 mm and bilateral neck cysts at the 13th gestational week. Both findings resolved spontaneously by the 18th gestational week, but during the third trimester this fetus developed hydrothorax, skin edema, and polyhydramnios. In the three other fetuses, first- and second-trimester ultrasonographic findings were normal, and the diagnosis of Noonan syndrome was suggested only during the third trimester. All three fetuses had polyhydramnios and skin edema. A cardiac malformation, hydrothorax, and a large head were present in one fetus. Sonographic facial findings were investigated. In all four fetuses posteriorly angulated, apparently low-set ears and depressed nasal bridge were identified. Wide nasal base was seen in two fetuses. In two fetuses, persistent opening of the fetal mouth was interpreted as fetal hypotonia. One fetus developed progressive postnatal hypertrophic cardiomyopathy and in one case, pulmonic stenosis became apparent at age 6 months. This small series suggests that Noonan syndrome has an evolving phenotype during in utero and postnatal life. Amelioration of early nuchal region findings and late onset of the more "typical" ultrasonographic changes may limit early prenatal detectability.
Enlargement of the subarachnoid spaces can be seen in the following conditions: communicating hydrocephalus, brain atrophy and benign enlargement of the subarachnoid spaces. These disorders may begin in utero. There are no established normograms for the fetal subarachnoid spaces. This study was conducted in order to determine its normal development. Transvaginal sonography was used to examine the subarachnoid space in 80 fetuses between 16 and 40 weeks' gestation. The sinocortical width (SCW) and craniocortical width (CCW) were measured in a coronal plane at the level of the foramen of Monro. The SCW remained relatively constant during the gestational period. The CCW increased in size from the 20th to the 28th week of pregnancy, with a subsequent gradual decrease until term. Determination of fetal subarachnoid space normograms may potentially help in the diagnosis of pathological conditions affecting this space and allow prenatal counselling.
The aims of this prospective, cross-sectional study were to report axial ocular growth during human gestation, to determine the presence of the hyaloid artery (HA) and its blood flow, and to provide a timetable for HA regression. The study group comprised 231 low-risk singleton pregnancies between 14 and 38 weeks' gestation. Ocular axial length (OAL), anterior chamber depth (ACD) and posterior chamber depth (PCD) were measured using high-resolution ultrasound. The growth of these eye segments in correlation with gestational age (GA) was established. The presence of the HA and its regression were determined. By using power Doppler, ultrasound blood flow within the HA was estimated. HA regression is a gradual process that is not evident before 18 weeks' gestation. In all fetuses beyond 29 weeks' gestation, no HA could be detected (P<0.001). Blood flow within the HA was documented only until the 16th week of gestation. The correlation coefficients, r=0.924, 0.784 and 0.929, for OAL, ACD and PCD, respectively, were found to be highly statistically significant (P<0.0001). The present data offer normative measurements of the fetal axial eye lengths, timetable for HA regression and flow cessation.
OBJECTIVE: To establish in-utero reference ranges for fetal transverse aortic arch diameter (TAD) and distal aortic isthmus diameter (DAID) using high-resolution ultrasound techniques. DESIGN: A prospective, cross-sectional study was performed on 125 normal singleton pregnancies between 14 and 38 weeks' gestation. Transverse and diameter and DAID were measured by transvaginal ultrasonography until 17 weeks' gestation, and by abdominal ultrasound between 18 and 38 weeks' gestation. RESULTS: Transverse arch diameter as a function of gestational age was expressed by the regression equation TAD = -1.17 + 0.169 X GA, and DAID = -1.39 + 0.189 X GA; TAD and DAID are transverse aortic and distal aortic isthmus diameters expressed in millimeters and GA is gestational age in weeks. The correlation r = 0.924 and 0.938 was found to be highly statistically significant (P < 0.001) for TAD and DAID. The normal mean of TAD and DAID per week and the 95% prediction limits were also defined. CONCLUSIONS: The normative data established by us may be helpful in the prenatal diagnosis of congenital heart defects, including abnormal growth of the aortic arch.
OBJECTIVES: Anomalies of the fetal venous system are poorly documented and their pathogenesis is not well understood. The present study was undertaken to review the spectrum of fetal central veins and umbilico-portal system anomalies, and to propose a classification system. METHODS: A 7-year restrospective survey was conducted. RESULTS: Nineteen fetuses showed abnormal connection between central veins and the fetal heart. Three fetuses showed abnormal connections of the cardinal veins, two of which had interruption of the inferior vena cava, and one had isolated persistent left superior vena cava. Anomalies of pulmonary veins were seen in four fetuses: in two with asplenia syndrome, a vertical confluent pulmonary artery was observed. In a further two cases total anomalous pulmonary venous connections were found. Abnormalities of the umbilical vein (UV) were seen in 10 cases; seven had persistent right UV, and three had a spectrum of anomalies: One had abnormal connections of the UV to the left iliac vein associated with agenesis of the ductus venosus (DV) and hydrops fetalis. One case showed in utero occlusion of the DV by echogenic foci that resulted in a persistent left proximal UV and porto-systemic shunt. One case had obliteration of the DV secondary to in utero fetal hepatic fibrosis. Abnormalities of the vitelline veins or portal system were demonstrated in two cases. One had a left porto-systemic shunt which resolved spontaneously at 3 months of age, and one had secondary partial occlusion of the left portal system with liver echogenicities and direct communication of the UV with the right atrium. None of the 19 cases had an abnormal karyotype or evidence of in utero infection. CONCLUSIONS: Detection of various fetal vein anomalies in utero is feasible. The anomalies vary according to embryologic precursors or etiology. Two major mechanisms seem to be involved in the genesis of fetal vein anomalies: in most cases primary maldevelopment of the venous system occurs, while in the minority secondary anomalies from possible thromboembolic events or systemic disease may play a role.
Urorectal septum malformation sequence (URSMS) is a rare congenital malformation, which includes ambiguous genitalia, a phallus-like structure, imperforate anus, bladder, vaginal and rectal fistulas and Müllerian duct defects. We report two cases of prenatally diagnosed URSMS, both occurring in two sets of discordant twins. To the best of our knowledge, this is the first antenatal description of such an anomaly. The first fetus, one of a set of monochorionic, monoamniotic twins was detected sonographically at 21 weeks of gestation due to an enlarged phallus-like formation. The second fetus, one of dichorionic, diamniotic twins, was suspected of having an abnormally enlarged rectum at 13 weeks of gestation. The diagnosis of URSMS was established at 29 weeks of gestation by showing abnormal female external genitalia, with a dilated bowel that contained echogenic foci due to enterolithiasis. The diagnosis of both cases was confirmed postnatally. Sonographic findings and differential diagnosis are presented.
OBJECTIVE: To evaluate changes in human, fetal segmentary, pulmonary artery blood flow velocimetry throughout pregnancy. DESIGN: Ninety-nine women with a singleton, low-risk gestation between 14 and 37 weeks of pregnancy were selected to participate in a prospective, cross-sectional study. All fetuses were evaluated using power and color Doppler ultrasound. Flow velocity waveforms at three sites of the right pulmonary artery were obtained. The pulsatility index (PI) was calculated in the proximal, mid and distal segment of the pulmonary artery. Mean values and 95% confidence interval (CI) for each segment were determined in correlation with gestational age. RESULTS: A full study that included Doppler measurements of all three segments of the pulmonary artery was completed on 99 fetuses. The highest mean PI of 2.36 was obtained in the proximal segment of the right pulmonary artery (CI = 2.29-2.42), whereas in the mid and distal segments the mean PI decreased significantly to 1.57 (CI = 1.53-1.61) and 1.02 (CI = 1.0-1.0) (P < 0.001), respectively. Throughout gestation, the mean PI measurements in the proximal, middle and distal segments of the branch pulmonary artery increased slightly, but without statistical significance (r = 0.274, 0.248, 0.047), respectively; (P > 0.5). CONCLUSIONS: The data obtained suggests that pulmonary circulation maintains stable vascular resistance during gestation in the human fetus. However, the PI obtained from the separate segments of the branch pulmonary artery is unique and each differs from the other, reflecting the proximity to the heart and the peripheral impedance at each location.
Varix of the fetal intra-abdominal umbilical vein (FIUV) is a rare entity. We describe an ultrasound diagnosis of this condition together with a review of the literature relating to its prognosis and management. Our conclusion is that close fetal monitoring should be performed, and delivery should be induced when lung maturity has been accomplished or any fetal distress is apparent.
OBJECTIVES: Our goal was to perform an analysis of ultrasonographic characteristics and CA 125 levels in ovarian tumors of borderline malignancy. STUDY DESIGN: We performed a retrospective analysis of CA 125 levels and ultrasonographic parameters in 91 patients with borderline tumors. RESULTS: Serous tumors of borderline malignancy were associated with elevated CA 125 levels in 75% of patients before surgery (mean, 156 IU/mL) compared with 30% of mucinous tumors (mean, 28 IU/mL; P =.004). CA 125 was elevated in 35% of stage IA serous tumors (mean, 67 IU/mL) compared with 89% of tumors with spread beyond the ovary (mean, 259 IU/mL; P =.001). Mucinous tumors tended to be bigger (13.1 +/- 7 cm) on ultrasonography than serous tumors (9.3 +/- 6.2 cm, P =.016). Mucinous tumors were multilocular in half the patients and contained papillations in 40% of the patients. Serous tumors were multilocular in 30% of the patients but presented with solid or papillary patterns in 78% of the patients (P =.001). A resistance index of <0.4 was found in 36% of mucinous tumors and half the cases of serous tumors. In 13% of patients, ultrasonographic characteristics were compatible with a simple cyst only, including 1 patient with microinvasion and 1 patient with stage IIIB disease. Sensitivity of gray-scale ultrasonography was 87%, that of CA 125 measurement was 62%, and that of flow was 55%. At least 1 diagnostic test result was abnormal in 93% of patients, 2 were abnormal in 69% of patients, and all 3 were abnormal in 21% of patients. CONCLUSIONS: A high proportion of borderline tumors of the ovary, particularly of the serous type, were associated with elevated CA 125 levels and abnormal ultrasonographic characteristics, although some tumors presented as simple cysts.