title: The pregnant population and a fetal crown-rump length screening program.
abstract: Ultrasound screening for estimation of gestational age is one of the most important advances made in obstetrics. In this study on the effects of our crown-rump length (CRL) screening program, a most significant (25%) proportion of the pregnant women had a difference between menstrual age and gestational age estimated on the basis of crown-rump length, exceeding 7 days. Regular menstrual cycles and reliable menstrual history could only reduce this frequency to 19%. Postmature deliveries (greater than 294 days menstrual age) were reduced from one in fifteen to one in three hundred. A screening program with CRL is useless if the woman books in too late, since a CRL above 90 mm is unreliable because of differences in fetal bending of the spine. In our catchment area more than 78% of the women delivered booked early enough for a fetal CRL measurement. If this result can be expected in a population, CRL measurement should be used because of its better accuracy than biparietal diameter measurement for the estimation of gestational age.
mesh_terms: D000028:Abortion, Induced; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007233:Infant, Postmature; D008403:Mass Screening; D008598:Menstruation; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D014463:Ultrasonography