{Reference Type}: Journal Article
{Title}: Association between interpregnancy interval and the labor curve.
{Author}: Burd J;Woolfolk C;Frolova A;Zofkie A;Odibo A;Carter EB;Kelly JC;Cahill AG;Raghuraman N;
{Journal}: Am J Obstet Gynecol MFM
{Volume}: 6
{Issue}: 8
{Year}: 2024 Aug 11
{Factor}: 8.679
{DOI}: 10.1016/j.ajogmf.2024.101425
{Abstract}: BACKGROUND: Both short and long interpregnancy intervals are associated with adverse pregnancy outcomes; however, the impact of interpregnancy intervals on labor progression is unknown.
OBJECTIVE: We examined the impact of interpregnancy intervals on the labor curve, hypothesizing that those with a longer interpregnancy intervals would have slower labor progression.
METHODS: This is a retrospective cohort study of patients with a history of one prior vaginal delivery admitted for induction of labor or spontaneous labor with a singleton gestation ≥37 weeks at an academic medical center between 2004 and 2015. Repeated measures regression was used to construct labor curves, which were compared between patients with short interpregnancy intervals, defined as <3 years since the last delivery, and long interpregnancy intervals, defined as >3 years since the last delivery. We chose this interval as it approximates the median birth interval in the United States. Interval-censored regression was used to estimate the median duration of labor after 4 centimeters of dilation, stratified by type of labor (spontaneous vs induced). Multivariate analysis was used to adjust for potential confounders.
RESULTS: Of the 1331 patients who were included in the analysis, 544 (41%) had a long interpregnancy interval. Among the entire cohort, there were no significant differences in first or second-stage progression between short and long interpregnancy interval groups. In the stratified analysis, first-stage progression varied between groups on the basis of labor type: long interpregnancy interval was associated with a slower active phase among those being induced and a quicker active phase among those in spontaneous labor. The second-stage duration was similar between cohorts regardless of labor type.
CONCLUSIONS: Multiparas with an interpregnancy interval >3 years may have a slower active phase than those with a shorter interpregnancy interval when undergoing induction of labor. Interpregnancy interval does not demonstrate an effect on the length of the second stage.