Is the Relationship between Short Interpregnancy Interval and Preterm Birth Related to a Short Cervix?
ObjectiveOur objective was to determine if the relationship between interpregnancy interval (IPI) and preterm delivery was related to cervical shortening.MethodsThis is a secondary analysis of a prospective cohort study designed to assess the relationship between cervical length (CL) and preterm delivery. Multiparous patients, who had transvaginal CLs obtained at 22 to 24 weeks and complete pregnancy outcome data available were included. The women were divided into two groups: Group 1 with an IPI of ≤ 1 year and Group 2 with an IPI of > 1 year. The primary outcome was short cervix (CL < 2.5 cm) at 24 weeks. The secondary outcome was the incidence of preterm delivery < 37 weeks. Interaction between short cervix and IPI was examined in a regression model.ResultsThere were 155 women in Group 1 and 328 women in Group 2. There was no difference in the incidence of short cervix between groups (10.0% in Group 1 and 12.9% in Group 2,p= 0.35). In a logistic regression model, short IPI and short cervix were independently associated with preterm birth.ConclusionThe relationship between short IPI and preterm birth is not explained by a short cervix. They remain independent risk factors for preterm birth.
Department of Obstetrics and Gynecology, New York Presbyterian Hospital/Queens, Weill Cornell College of Medicine, New York, New York.
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Govindappagari
Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York.
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Zork
Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York.
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Merriam
Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York.
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Gyamfi-Bannerman
D000328:Adult; D001721:Birth Intervals; D054791:Cervical Length Measurement; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D012307:Risk Factors; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D055815:Young Adult