The head circumference to chest circumference ratio provided an easy way to detect foetal growth restriction in term infants.

AIM: The head circumference to chest circumference (HC/CC) ratio has been used to identify low birth weight infants in developed countries. This study was conducted to examine whether the ratio could distinguish asymmetrical foetal growth restriction (FGR). METHODS: This retrospective observational study was conducted with 1955 infants (50.5% male) born at term between 2016 and 2020 at Tokyo Metropolitan Toshima Hospital, Japan. RESULTS: We found that 120 (6.1%) had FGR. Their mean birth weight was 3052.1 ± 367.3 g, and their mean gestational age was 39.1 ± 1.1 weeks. Logistic regression analysis showed that the association between the HC/CC ratio and FGR had a regression coefficient of -20.6 (p < 0.000). The linear regression analysis showed that the association between the HC/CC ratio and the birth weight z-score had a regression coefficient of -8.59 (p < 0.000). The coefficient of correlation was -0.33 (p < 0.001). The receiver operating characteristic curve for detecting FGR showed that the area under the curve was 0.75 and the cut-off value was 0.93, with sensitivity of 75.8% and specificity of 60.8%. CONCLUSION: Our study established the associations between HC/CC ratio and FGR and birth weight z-scores and confirmed that the ratio provided an easy way to detect FGR in term-born infants.

Changes in umbilical arterial blood flow by an intraamniotic distilled water infusion.

OBJECTIVES: The purpose is to investigate how umbilical arterial blood flow changes by an intraamniotic distilled water infusion and to determine whether the changes in umbilical circulation have any relationship with fetal cardiovascular status and osmolality in amniotic fluid and fetal plasma. METHODS: Eleven chronically catheterized pregnant sheep were used in this study. After a 1-hour control period, 1.5 L of warmed sterile distilled water was injected over 10 minutes into the amniotic cavity. Fetal heart rate and carotid arterial pressure, blood flow of the umbilical and fetal carotid arteries were continuously measured. Fetal arterial blood sampled twice during the control period and then at 30, 60, 90, 120, 180, 240, 300, and 360 minutes after the start of the infusion, was analyzed for blood gases, pH, plasma electrolytes, and osmolality. RESULTS: Data obtained from seven sheep with normoxemic fetuses were studied statistically. Umbilical arterial blood flow decreased significantly from 229.5 +/- 3.83 mL/min in the control to 167.4 +/- 11.1 mL/min at 30 minutes after water infusion (P < .001). Umbilical arterial vascular resistance increased rapidly and reached its peak at approximately 60 minutes after infusion and then showed a gradual recovery to the control level (P < .001). Amniotic fluid osmolality had a high degree of correlation with umbilical arterial blood flow and vascular resistance, while fetal arterial blood pressure and heart rate had only little correlation with umbilical blood flow. CONCLUSION: A distilled water infusion into the amniotic cavity in near-term pregnant sheep led to an acute drop in umbilical arterial blood flow. The changes in umbilical flow were closely correlated with those in amniotic fluid osmolality. Hemolysis in the capillary networks in the fetal membranes seems to be one of the main causes of umbilical vasoconstriction. It is speculated that the fetal membranes, including capillary networks, intramembranous pathway, and amnion epithelial cells, sense the changes in amniotic fluid osmolality, which leads to a fetal adaptation to the hypotonic environment.

Fractal tumor growth of ovarian cancer: sonographic evaluation.

OBJECTIVE: The objective of this study was to determine whether sonographically depicted ovarian tumor growth is fractal, and the mean fractal dimension differs according to stages of the disease and histologic types. METHODS: The fractal dimensions of outlines of sonographically depicted solid components in 160 ovarian tumors were measured using a box-counting method. RESULTS: The mean fractal dimensions of the surface of intracystic solid components in serous, mucinous, endometrioid, and clear cell adenocarcinoma were 1.259, 1.243, 1.238, and 1.182, respectively. These values were significantly greater than the topological dimension of a line (=1). The value was significantly higher in stage I or II (1.381) than stage III or IV (1.205) in serous carcinoma (P = 0.02), but not significantly different in clear cell carcinoma (1.187 and 1.172, respectively). In stage I or II, the value of serous carcinoma (1.381) was significantly higher than that of clear cell carcinoma (1.187) (P = 0.03). The value of mucinous cystadenoma of low malignant potential was 1.337, which was also significantly greater than 1. The mean fractal dimensions of outlines of solid tumors in cases with dysgerminoma and thecoma-fibroma were 1.036 and 1.023, respectively. These values were not significantly different from 1. CONCLUSION: This study shows that the surface of solid components in cystic epithelial ovarian cancers has a fractal structure, and the mean fractal dimension may differ according to stages of the disease and histologic types. Fractal geometry, a vocabulary of irregular shapes, can be useful for describing the pathological architecture of ovarian tumors and for yielding insights into the mechanisms of tumor growth.

Parovarian cystadenoma: sonographic features associated with magnetic resonance and histopathologic findings.

Differentiation between malignant and benign parovarian tumors is necessary before any surgery is planned, because the postoperative spread of ovarian cancers is well documented. Both malignant and benign parovarian tumors may contain intracystic projections, so their presence is not a differentiating factor. We describe the cases of 2 patients with parovarian cystadenomas that were evaluated using sonography, MRI, and histopathology in an attempt to begin to identify the sonographic characteristics of such lesions and correlate them with MRI and histopathologic findings. In both cases, sonography revealed a cystic mass that contained multiple small intracystic mural nodules, most of which were associated with the "Chinese hat" artifact. MRI findings confirmed the presence of the cystic masses and the nodules. Histopathologic findings confirmed the diagnosis of serous cystadenoma arising in a parovarian cyst; the intracystic nodules consisted of fibrotic tissue covered with a single layer of epithelium. Thus, the results of all 3 evaluations correlated well. This characteristic sonographic appearance may be useful in making an accurate preoperative diagnosis of parovarian cystadenomas.