Korean J Obstet Gynecol.  2006 Feb;49(2):357-364.

Normal Reference Range for Cervical Length in Twin Pregnancy using transvaginal ultrasound

• Kim HJ
• Hong JS
• Park KH
• Jung JY
• Park HE
• Kim HJ
• Han SH
• Jeon YT
• Jee BC
• Kim YB
• Suh CS

Abstract

OBJECTIVE
We performed prospective longitudinal study to establish reference range for cervical length and evaluate the change in cervix throughout pregnancy in twin pregnancy.
METHODS
Fifty-four women of twin pregnancy without history of preterm labor, preterm delivery, cervix cerclage, that delivered at or after 36 weeks were included in this study. Serial measurements of cervical lengths by transvaginal ultrasound exam were performed at 20 weeks of gestation and every 4 weeks (until 28 weeks), every two weeks (until 36 weeks) and every week until delivery. Linear regression analysis was done for statistical analysis.
RESULTS
The reference range for cervical length in twin pregnancy was presented as mean, standard deviation and 95% confidence interval of the mean. Cervical length gradually decreased as the gestational age progressed. There was a significant correlation between cervical length measurements and gestational age (Y=71.361-1.336X, r2=0.384, p<0.05).
CONCLUSION
We presented the reference range for cervical length in twin pregnancy and evaluated the association between gestational age and cervical length. These results can be used as reference guideline in consecutive assessments of cervical lengths during twin pregnancy.

Keyword

Twin pregnancy; Cervical length; Prospective longitudinal study

MeSH Terms

Cervical Length Measurement
Cervix Uteri
Female
Gestational Age
Humans
Linear Models
Longitudinal Studies
Obstetric Labor, Premature
Pregnancy
Pregnancy, Twin*
Prospective Studies
Reference Values*
Ultrasonography*