Temporal changes in rates and reasons for medical induction of term labor, 1980-1996.
OBJECTIVE
This study was undertaken to assess temporal changes in rates and reasons for medical induction of term labor.


METHODS
A retrospective medical record review was conducted on a population-based cohort of 1293 women with term deliveries.


RESULTS
The rate of medical labor induction increased from 12.9% in 1980 to 25.8% in 1995. Stated indications also changed, with a 2-fold increase in induction for postdate gestation, a 23-fold increase in induction for macrosomia, a 15-fold increase in elective induction, and a 22-fold decline in induction for premature rupture of membranes. The average gestational age at delivery of postdate pregnancies declined from 41.9 weeks in 1980 to 41.0 weeks in 1995. By 1995, the average maternal length of stay and the percentage of cesarean deliveries were higher among women with induced labor at term than among those with spontaneous labor at term.


CONCLUSIONS
Induction of term labor has almost doubled in prevalence during the past 15 years. The most common indications are elective induction and postdate pregnancy, often applied to gestations of 40 to 41 weeks' duration.
Department of Research, Olmsted Medical Center, Rochester, MN 55904, USA.
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BP
Yawn
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P
Wollan
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K
McKeon
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CS
Field
D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D005320:Fetal Macrosomia; D005322:Premature Rupture of Fetal Membranes; D005865:Gestational Age; D006801:Humans; D007751:Labor, Induced / Q000639:trends*; D007902:Length of Stay / Q000706:statistics & numerical data; D008499:Medical Records; D011247:Pregnancy; D011273:Pregnancy, Prolonged; D012189:Retrospective Studies; D013997:Time Factors