TRANSVAGINAL SONOGRAPHIC BIOMETRY IN EARLY-PREGNANCY - A GROWTH-MODEL

Purpose: Evaluation of a growth model for the biometric parameters of early pregnancy: Chorionic cavity, yolk sac, amniotic cavity, crown-ru mp length and biparietal diameter. Method: 618 clinically well-dated s ingleton pregnancies of the first trimester were measured in a prospec tive cross-sectional study with high-frequency transvaginal ultrasound between 28 and 94 days post menstruation. Results: Normal curves (5th , 50th, 95th percentiles) for all parameters were established using ou r growth model. The growth curves of chorionic cavity amniotic cavity, and biparietal diameter showed a linear growth whereas the growth cur ve of the crown-rump-length represented an exponential curve. Linear g rowth of the yolk sac was found until 8 weeks of gestation and there w as no growth alteration after this time. Conclusion: With our growth c urves of the first trimester it is possible to monitor the embryonic d evelopment with several parameters.