B. Arabin et al., MATERNAL POSITION AND ULTRASONIC CERVICAL ASSESSMENT IN MULTIPLE PREGNANCY - PRELIMINARY-OBSERVATIONS, Journal of reproductive medicine, 42(11), 1997, pp. 719-724
OBJECTIVE: To evaluate the influence of position on the functional ana
tomy of the cervix. STUDY DESIGN: Cervical length and width of the int
ernal of were measured by transvaginal ultrasound in the recumbent and
standing position from 15 gestational weeks to term in 15 twin and 3
triplet pregnancies. Measurements on asymptomatic primigravidae with t
wins who delivered vaginally after 36 weeks were made to calculate tre
nds in normal twin pregnancies. These data were compared with that obt
ained in patients who had threatened preterm labor. RESULTS: As the to
tal observation period progressed, the mean cervical length decreased
from 50 to 27 mm in the recumbent position and from 48 to 21 mm in the
standing position (P < .001). The differences between the values obta
ined in the recumbent and standing position increased from 5% to 31% a
s pregnancy progressed (P < .001). Funnelling was observed from 20 wee
ks onwards in the erect position but only after 35 weeks in the recumb
ent position. CONCLUSION Our preliminary observations support a policy
aimed at prevention of prematurity by reducing physical activity and
standing work in patients who have multiple gestations. The full impac
t of these observations on the early defection of special risk groups
and the prescription of preventive interventions have yet to be evalua
ted.