Term prediction in routine ultrasound practice.
OBJECTIVE
Evaluation of the precision of routine ultrasound term prediction.


METHODS
Population based follow-up without intervention.


METHODS
Ultrasound screening in routine clinical practice.


METHODS
1650 women residing in one Norwegian county giving birth during a 12-month period. All pregnancies were singleton with spontaneous onset of labor, all records contained a term predicted with routine ultrasound in the second trimester.


METHODS
Difference between actual and predicted day of delivery, and difference between ultrasound predicted term and term calculated from last menstrual period.


RESULTS
More women delivered within two weeks of ultrasound term than two weeks of term calculated from the last menstrual period (87.5% and 79.3%, p < 0.001). Deliveries were significantly closer to the ultrasound predicted term than the term calculated from the last menstrual period, with the exception of deliveries in the 39th week after LMP where no significant difference was found between ultrasound term and LMP-term. No difference was found in the mean performance of 14 different ultrasound operators.


CONCLUSIONS
In a population representative of deliveries in one county, routine ultrasound term prediction performed in three medium sized hospitals more accurately predicted day of delivery than term calculated from the date of last menstrual period.
Backe
B
B
Norwegian Institute of Hospital Research, Trondheim.
Nakling
J
J
D000704:Analysis of Variance; D001724:Birth Weight; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007745:Labor Onset; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011295:Prenatal Care; D016216:Ultrasonography, Prenatal