Relationship between mechanical properties of the uterine cervix and occurrence of postdate pregnancy.
Postmaturity is associated with an increased risk of fetal distress and of intrauterine fetal death. In order to assess the probability of the occurrence of postdate delivery, we have determined the Bishop score and measured the cervical distensibility index (CDI) using a cervicotonometer in 52 normal pregnant primiparous women between 37 and 40 weeks of pregnancy. 16 out of the 52 patients delivered after 41 weeks. Bishop scores and CDI were significantly lower in women who delivered after term than in those who delivered at or before 41 weeks (p less than 0.05; Student's test). The patients who had both a low Bishop score (less than or equal to 4) and a CDI less than 4 cm.kg-1 delivered after 41 weeks in 73% of the cases. Those who had a Bishop score less than or equal to 4 associated with a CDI greater than 4 cm.kg-1 delivered at or before 41 weeks in 80% of the cases. These results confirm the etiologic role of incomplete cervical maturation in postdate pregnancies. CDI measurement associated with the Bishop score could permit selection of the patients who would benefit from pharmacological cervical ripening.
Cabrol
D
D
INSERM U-166, Paris, France.
Carbonne
B
B
Ledieu
C
C
Lussiana
F
F
D000886:Anthropometry / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D002584:Cervix Uteri / Q000033:anatomy & histology*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D011247:Pregnancy; D011273:Pregnancy, Prolonged / Q000502:physiology*; D011379:Prognosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index