Effect of Cervical Length to The Efficacy of Nifedipine and Bed Rest for Inhibiting Threatened Preterm Labor
Saifon Chawanpaiboon MD*, Anuwat Sutantawibul MD*
Affiliation : * Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To compare the success rates and gestational ages at delivery of nifedipine administration as a tocolytic agent to
pregnant women with threatened preterm labor based on cervical length.
Material and Method: One hundred eighty eight pregnant women with threatened preterm labor between 26 and 35 weeks
were enrolled in the present study. Cervical measurement was performed in all patients and divided in two groups. The first
group, 60 cases, was patients with cervical length less than 30 mm. The second group, 128 cases, was patients with cervical
length 30 mm or greater. All women in each group were randomly inhibited uterine contraction with nifedipine and were bed
rest.
Results : If the cervical length was 30 mm or greater, nifedipine and bed rest succeeded to inhibit uterine contraction without
statistical significance. Nifedipine was appropriate for contraction inhibition when the cervical length was less than 30 mm
with statistical significance.
Conclusion : Nifedipine and bed rest can be used successfully to inhibit contractions in threatened preterm labor. However,
nifedipine should be used if the cervical length is less than 30 mm. If cervical length is 30 mm or greater, bed rest should be
advised to avoid unnecessary medical intervention.
Keywords : Cervical length, Nifedipine, Bed rest, Threatened preterm labor
