Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Hormonal Effects on Pain Perception (HEPP)

This study has been completed.
Information provided by (Responsible Party):
Michael Froelich, University of Alabama at Birmingham Identifier:
First received: June 13, 2008
Last updated: November 8, 2014
Last verified: November 2014

To investigate if labor pain is affected by mother's hormone levels.

The hormonal effects of pregnancy are well documented. Although differences in pain sensitivity between women and men are partly attributable to social conditioning and to psychosocial factors, many laboratory studies of humans have described sex differences in sensitivity to noxious stimuli, suggesting that biological mechanisms underlie such differences. Some animal studies have suggested that sensitivity to pain decreases during pregnancy because of the progressive activation of endogenous pain inhibitory systems. This effect may be mediated by pregnancy-associated hormones, in particular progesterone.

Progesterone Levels
Pregnancy Associated Analgesia

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Hormonal Effects on Pain Perception

Further study details as provided by Michael Froelich, University of Alabama at Birmingham:

Primary Outcome Measures:
  • Change in heat pain threshold and tolerance [ Time Frame: 1 month ]

Biospecimen Retention:   None Retained
Plasma for progesterone levels

Enrollment: 50
Study Start Date: September 2008
Study Completion Date: November 2014
Primary Completion Date: November 2014 (Final data collection date for primary outcome measure)
Term pregnant women
Healthy women scheduled for elective Cesarean section.


Ages Eligible for Study:   19 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Healthy term pregnant women

Inclusion Criteria:

  • healthy pregnant women at term (>37GA)

Exclusion Criteria:

  • chronic pain
  • regular analgesic medication
  • severe cardiopulmonary problems
  • very difficult intravenous access
  • advanced labor
  • precipitous delivery
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00699595

United States, Alabama
University of Alabama at Birmingham
Birmingham, Alabama, United States, 35294
Sponsors and Collaborators
University of Alabama at Birmingham
Principal Investigator: Michael Froelich, MD, MS University of Alabama at Birmingham
  More Information

Responsible Party: Michael Froelich, Principal Investigator, University of Alabama at Birmingham Identifier: NCT00699595     History of Changes
Other Study ID Numbers: F070721003
Study First Received: June 13, 2008
Last Updated: November 8, 2014 processed this record on May 25, 2017