[Transvaginal ultrasound 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-rump length and biparietal diameter.

METHOD

618 clinically well-dated singleton pregnancies of the first trimester were measured in a prospective 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 our growth model. The growth curves of chorionic cavity amniotic cavity, and biparietal diameter showed a linear growth whereas the growth curve of the crown-rump-length represented an exponential curve. Linear growth of the yolk sac was found until 8 weeks of gestation and there was no growth alteration after this time.

CONCLUSION

With our growth curves of the first trimester it is possible to monitor the embryonic development with several parameters.