PT  - JOURNAL ARTICLE
AU  - P Buekens
AU  - P Delvoye
AU  - E Wollast
AU  - C Robyn
TI  - Epidemiology of pregnancies with unknown last menstrual period.
AID  - 10.1136/jech.38.1.79
DP  - 1984 Mar 01
TA  - Journal of Epidemiology and Community Health
PG  - 79--80
VI  - 38
IP  - 1
4099  - http://jech.bmj.com/content/38/1/79.short
4100  - http://jech.bmj.com/content/38/1/79.full
SO  - J Epidemiol Community Health1984 Mar 01; 38
AB  - A group of women with unknown last menstrual period was studied representing 16% of a total of 22 404 pregnant women recorded using a common perinatal form. Unknown menstrual period is associated with high rates of low birth weight and with low socioeconomic and sociodemographic status. Such characteristics are also associated with a high rate of preterm deliveries. Thus any possible bias introduced in studies of prematurity by ignoring the group of women with unknown last menstrual period should be carefully checked.