Abstract
Objective: The purpose of this study was to determine if intrapartum contractions of a particular shape (rapid rise with slower return to baseline) are predictive of cephalopelvic disproportion (CPD). Study design: In an institutional review board (IRB)-approved study, cohorts of 100 women who underwent spontaneous vaginal delivery (SVD) and 100 who underwent cesarean section (C/S) for CPD or arrest of labor were consecutively identified between January 2004 and March 2005. Inclusion criteria included term, singleton pregnancies, nulliparity, and absence of fetal anomalies. One hour of interpretable electronic fetal monitoring (EFM) was obtained in active labor. Fall to rise (F:R) ratio was calculated by measuring the time for a contraction to return to its baseline from its peak ("fall") and the time for a contraction to rise to its peak ("rise"). The F:Rs were then averaged over the number of contractions. Data were analyzed using Student t test, Chi-square, and Fisher exact tests where appropriate. Results: Maternal demographics are listed in Table I. The average F:R ratio was 1.55 for SVD versus 1.77 for C/S, a statistically significant difference (P = .00003). Analysis of variance revealed this difference persists when controlled for the potentially confounding factors shown. At F:R >1.76, moreover, there was a trend towards larger birth weight (P = .06). Conclusion: Our study demonstrates there is a difference in uterine contraction configuration that is more common in those labors destined for C/S due to CPD. This may indicate the presence of a heretofore unknown feedback mechanism as the uterus adapts to the dysfunctional labor.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 739-742 |
| Number of pages | 4 |
| Journal | American Journal of Obstetrics and Gynecology |
| Volume | 195 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2006 |
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Keywords
- Cephalopelvic disproportion
- Fall:Rise ratio
- Tocodynamometry
ASJC Scopus subject areas
- Medicine(all)
- Obstetrics and Gynecology
Cite this
Cephalopelvic disproportion is associated with an altered uterine contraction shape in the active phase of labor. / Althaus, Janyne E.; Petersen, Scott; Driggers, Rita Wesley; Cootauco, Alice; Bienstock, Jessica L; Blakemore, Karin.
In: American Journal of Obstetrics and Gynecology, Vol. 195, No. 3, 09.2006, p. 739-742.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cephalopelvic disproportion is associated with an altered uterine contraction shape in the active phase of labor
AU - Althaus, Janyne E.
AU - Petersen, Scott
AU - Driggers, Rita Wesley
AU - Cootauco, Alice
AU - Bienstock, Jessica L
AU - Blakemore, Karin
PY - 2006/9
Y1 - 2006/9
N2 - Objective: The purpose of this study was to determine if intrapartum contractions of a particular shape (rapid rise with slower return to baseline) are predictive of cephalopelvic disproportion (CPD). Study design: In an institutional review board (IRB)-approved study, cohorts of 100 women who underwent spontaneous vaginal delivery (SVD) and 100 who underwent cesarean section (C/S) for CPD or arrest of labor were consecutively identified between January 2004 and March 2005. Inclusion criteria included term, singleton pregnancies, nulliparity, and absence of fetal anomalies. One hour of interpretable electronic fetal monitoring (EFM) was obtained in active labor. Fall to rise (F:R) ratio was calculated by measuring the time for a contraction to return to its baseline from its peak ("fall") and the time for a contraction to rise to its peak ("rise"). The F:Rs were then averaged over the number of contractions. Data were analyzed using Student t test, Chi-square, and Fisher exact tests where appropriate. Results: Maternal demographics are listed in Table I. The average F:R ratio was 1.55 for SVD versus 1.77 for C/S, a statistically significant difference (P = .00003). Analysis of variance revealed this difference persists when controlled for the potentially confounding factors shown. At F:R >1.76, moreover, there was a trend towards larger birth weight (P = .06). Conclusion: Our study demonstrates there is a difference in uterine contraction configuration that is more common in those labors destined for C/S due to CPD. This may indicate the presence of a heretofore unknown feedback mechanism as the uterus adapts to the dysfunctional labor.
AB - Objective: The purpose of this study was to determine if intrapartum contractions of a particular shape (rapid rise with slower return to baseline) are predictive of cephalopelvic disproportion (CPD). Study design: In an institutional review board (IRB)-approved study, cohorts of 100 women who underwent spontaneous vaginal delivery (SVD) and 100 who underwent cesarean section (C/S) for CPD or arrest of labor were consecutively identified between January 2004 and March 2005. Inclusion criteria included term, singleton pregnancies, nulliparity, and absence of fetal anomalies. One hour of interpretable electronic fetal monitoring (EFM) was obtained in active labor. Fall to rise (F:R) ratio was calculated by measuring the time for a contraction to return to its baseline from its peak ("fall") and the time for a contraction to rise to its peak ("rise"). The F:Rs were then averaged over the number of contractions. Data were analyzed using Student t test, Chi-square, and Fisher exact tests where appropriate. Results: Maternal demographics are listed in Table I. The average F:R ratio was 1.55 for SVD versus 1.77 for C/S, a statistically significant difference (P = .00003). Analysis of variance revealed this difference persists when controlled for the potentially confounding factors shown. At F:R >1.76, moreover, there was a trend towards larger birth weight (P = .06). Conclusion: Our study demonstrates there is a difference in uterine contraction configuration that is more common in those labors destined for C/S due to CPD. This may indicate the presence of a heretofore unknown feedback mechanism as the uterus adapts to the dysfunctional labor.
KW - Cephalopelvic disproportion
KW - Fall:Rise ratio
KW - Tocodynamometry
UR - http://www.scopus.com/inward/record.url?scp=33747877619&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33747877619&partnerID=8YFLogxK
U2 - 10.1016/j.ajog.2006.05.053
DO - 10.1016/j.ajog.2006.05.053
M3 - Article
C2 - 16949406
AN - SCOPUS:33747877619
VL - 195
SP - 739
EP - 742
JO - American Journal of Obstetrics and Gynecology
JF - American Journal of Obstetrics and Gynecology
SN - 0002-9378
IS - 3
ER -