The broad, long-term objectives of the Neuromuscular Injury and Recovery after Vaginal Delivery project are 1) to document the specific labor event or combination of events associated with the greatest evidence of short and long term neuromuscular maternal injury, and 2) to determine differences in these injury mechanisms between minority and Caucasian women. Immediate specific aims of this longitudinal study are: 1) documenting normal neuromuscular function and radiologic anatomy of pelvic and perineal muscles in nulliparous African-American and Hispanic women, 2) identifying, enrolling, and following a cohort of 135 primigravid women of representative ethnic groups to participate in antepartum, intrapartum, and postpartum electromyographic studies of pelvic and perineal muscle function, 3) studying the effects of epidural analgesia on striated muscle of maternal pelvis and perineum, and 4) comparing magnetic resonance imaging (MRI) studies of the pelvic anatomy of these women and correlating those findings to the functional EMG findings. These studies will provide a greater understanding of the mechanism of maternal pelvic injury at the time of vaginal delivery, which is the single greatest contributor to the risk of developing urinary incontinence (UI) and pelvic floor dysfunction (PFD). Furthermore, we will help close a gap in our significant knowledge deficit regarding racial differences in female pelvic floor function. The first phase of the study will involve the recruitment of nulliparous African-American and Hispanic women to establish normative values of pelvic musculature for that group via quantitative electromyography (QEMG) and pelvic MRI. This data, and normative data in Caucasian women from previous studies, will be used for the second phase of the study, which will study events in women of diverse racial backgrounds undergoing their first vaginal delivery. In this phase, primigravid subjects will undergo ~QEMG exam in the third trimester, again immediately prior to the second stage of labor, one day or two days postpartum, and 6 months postpartum. Precise measures of intrapartum events, including the descent of the fetal head in the pelvis, and time to actual delivery, will allow correlation with QEMG data. During the intrapartum phase, subjects will undergo QEMG exam before and after the placement of epidural analgesia, to precisely document the effect of epidural on the function of striated muscles of the pelvis. These subjects will also undergo pelvic MRI studies to provide anatomic correlation with functional QEMG data.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD038661-01
Application #
6080292
Study Section
Special Emphasis Panel (ZHD1-RRG-K (03))
Program Officer
Parrott, Estella C
Project Start
1999-09-30
Project End
2004-08-31
Budget Start
1999-09-30
Budget End
2000-08-31
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Duke University
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
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South, Mary M T; Stinnett, Sandra S; Sanders, Donald B et al. (2009) Levator ani denervation and reinnervation 6 months after childbirth. Am J Obstet Gynecol 200:519.e1-7
Branham, Virginia; Thomas, John; Jaffe, Tracy et al. (2007) Levator ani abnormality 6 weeks after delivery persists at 6 months. Am J Obstet Gynecol 197:65.e1-6
Downing, Keith T; Hoyte, Lennox P; Warfield, Simon K et al. (2007) Racial differences in pelvic floor muscle thickness in asymptomatic nulliparas as seen on magnetic resonance imaging-based three-dimensional color thickness mapping. Am J Obstet Gynecol 197:625.e1-4
Weidner, A C; Jamison, M G; Branham, V et al. (2006) Neuropathic injury to the levator ani occurs in 1 in 4 primiparous women. Am J Obstet Gynecol 195:1851-6
Hoyte, Lennox; Thomas, John; Foster, Raymond T et al. (2005) Racial differences in pelvic morphology among asymptomatic nulliparous women as seen on three-dimensional magnetic resonance images. Am J Obstet Gynecol 193:2035-40