[Clinical study of Osaka formula and improved multiparameter ultrasonic measurement for fetal weight estimation].

OBJECTIVE: To analyze the factors affecting the accuracy of Osaka formula multiparameter ultrasound-based fetal mass estimation, thereby establishing new formulas to improve the accuracy of the estimation. METHODS: A retrospective review was conducted among 519 healthy women with singleton pregnancy. Three days before the delivery (between 37 and 42 weeks' gestation), ultrasonic measurement of the fetal weight and other indices of the fetus was routinely performed. Correlation and multiple linear stepwise regression analysis were used to correct the 3 equations, which, along with Osaka University formula, were used to predict another 219 fetuses' birth weight. The coincidence rate of the predicted value and with the actual birth weight, and the absolute error and relative error were compared between the equations. RESULTS: The fetal abdominal area (AA) and abdominal circumference (AC) showed the most conspicuous influence on the estimated fetal birth weight, and fetal humerus length (HL) was more sensitive than femur length (FL) for the estimation. Three new regression equations were established, among which the equation 2 (fetal birth weight=1082.859+4.116xAAxHL) showed the best accuracy in clinical prediction. CONCLUSION: AA,AC and HL are more sensitive indices for estimation of the fetal birth weight, and the equation 2 established in this study still awaits further verification for its clinical value.

[Association between ultrasonographic signs of placental premature aging and pregnancy outcome].

OBJECTIVE: To explore the association between placental premature aging observed ultrasonographically and the pregnancy outcome. METHOD: The perinatal outcome of 30 pregnant women with grade III placenta observed ultrasonographically before 37 weeks of gestation were analyzed retrospectively, with 154 pregnant women with grade III placenta at full term (>37 weeks) selected at random to serve as the control. RESULT: The gestational age at delivery (37.38+/-2.10 weeks) and newborn birth weight (2 802.00+/-502.99 g) in cases of placental premature aging were significantly lower than those in the control group (39.48+/-2.44 weeks and 3 324.35+/-411.34 g, P<0.001), and the incidence of oligohydramnios (26.67%) and rate of cesarean delivery (96.67%) were significantly higher than those in the control group (6.49% and 48.36%, P<0.05). CONCLUSION: The ultrasonographic signs grade III placenta maturation before 37 weeks of gestation is associated with oligohydramnios and low birth weight and might help predict placental dysfunction, which needs close monitoring for the benefits of the mother and fetus.