The Effect of Pregnancy on Temporal Summation and Venipuncture Pain Perception

Recent studies have shown that women are more likely to experience pain in many medical situations. During pregnancy, women may experience an increase in pain threshold. This is thought to be related to hormonal changes and an increase in the level of certain natural pain-relieving substances in their bodies.

It is important to develop simple tests to identify woman at higher risk for pain so the investigators can help them.

Temporal summation is what happens when a person becomes more sensitive to a certain feeling on their skin when it is applied several times over the course of several seconds. The investigators hypothesize that pregnant women show decreased temporal summation and pain scores to venipuncture, compared to non-pregnant women.

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Key information

Conditions

Pain Neurologic Manifestations Pathological Conditions, Signs and Symptoms Pregnancy Signs and Symptoms

Age range

18 year–40 year

Sex eligibility

Female

Study type

Observational

Primary location

Mount Sinai Hospital

Toronto, Ontario, M5G1X5, Canada

About this study

Recent epidemiologic studies have shown that women are at substantially greater risk for many clinical pain conditions, and there is a suggestion that postoperative and procedural pain may be more severe among women then men. During pregnancy, women experience an elevation in the threshold to pain and discomfort. In addition to hormonal changes, the changes in pain perception during pregnancy may be related to an increase in endogenous opioids.

Pain is the most feared experience in the intra and postpartum period, and severe pain experienced during this time can lead to significant morbidity, including chronic pain and depression. Much attention has been paid to tests that can predict patients at higher risk for pain. Temporal summation (TS) has been shown to be a simple and reliable test. Temporal summation represents the physiological wind-up phenomenon taking place at the spinal level of the central pain pathways. TS extent can be measured in humans by administering a series of noxious stimuli of constant intensity and of various modalities in order to evoke an increase in perceived pain. It is a very simple and easy test to perform, and very well tolerated by patients. Whether TS changes in pregnancy and whether TS in pregnancy correlates with pain perception during acute stimuli such as venipuncture is unknown.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

informed consent
able to communicate in English
healthy pregnant patients in the 1st, 2nd and 3rd trimesters
healthy non-pregnant patients

Exclusion criteria

refusal to participate
Patients under age 18 or over age 40
Inability to communicate in English
Use of analgesics, anti-depressants and muscle relaxants
self-report of substance abuse
previous injury to the non-dominant arm/forearm

Sponsors and collaborators

Lead sponsor

Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Other

Registry information

Important dates

Study start: 2009
Primary completion: 2010
Study completion: 2010
First posted: Nov 23, 2009
Registry last updated: Sep 28, 2010

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed