Relationship between COMT Gene Polymorphism, Anxiety, and Pain Perception during Labour

Area of Science:

• Genetics
• Obstetrics
• Psychology

Background:

• The catechol-O-methyltransferase (COMT) gene polymorphism is linked to neurological conditions, psychiatric disorders, and pain perception.
• Investigating COMT gene variations in relation to anxiety and pain during labor is crucial for understanding individual responses to childbirth and analgesia.

Purpose of the Study:

• To examine the association between COMT gene polymorphism and pain perception in laboring women.
• To evaluate the influence of COMT gene polymorphism on anxiety levels during childbirth.
• To assess the efficacy of inhaled nitrous oxide analgesia in relation to COMT genotypes.

Main Methods:

• 181 women undergoing vaginal birth were divided into groups with (n=90) and without (n=91) inhaled nitrous oxide analgesia.
• COMT gene polymorphism was determined using PCR from blood samples collected during pregnancy.
• Pain perception was self-assessed using the Visual Analogue Scale (VAS), and anxiety was measured with the State Trait Anxiety Inventory (STAI-T).

Main Results:

• Prevalence of COMT genotypes: GG (22%), GA (53%), and AA (25%).
• A negative association was found between pain perception and the GA (mutant heterozygote) COMT genotype compared to the wild-type (GG), with 0.46 units lower pain perception.
• The AA genotype group exhibited lower anxiety trait scores than GA and GG groups (p > 0.042). Nitrous oxide showed analgesic effects in 22% of women with moderate pain.

Conclusions:

• COMT gene polymorphism significantly impacts pain perception and anxiety in laboring women.
• The GA genotype of the COMT gene is associated with reduced pain perception during childbirth.
• Nitrous oxide demonstrated anxiolytic efficacy, particularly in women with the AA genotype and mild anxiety.