Yijun Wang, Yilin Eileen Sim, Chin Wen Tan, Rehena Sultana, Anisa Suhaila Ab Razak, Alex Tiong Heng Sia, Ban Leong Sng

Background and Goal of Study: 
Central sensitization (CS) refers to abnormal and intense enhancement of pain in response to both noxious and nonnoxious stimuli by mechanisms in the central nervous system [1]. CS has been associated with the development of depression in general population [2]. However, their relationship in women experiencing labour remains unclear. Severe labour pain predisposed women to increased risk of postnatal depression (PND) [3]. CS disrupts both ascending and descending pain regulation pathways, and may contribute to PND by exacerbating labour pain [4]. We therefore propose to examine if there was a correlation between CS and PND in the parturient population. 

Materials and Methods: 
This pilot analysis is part of an ongoing clinical trial recruiting healthy, term, singleton parturients. The Central Sensitization Inventory (CSI) was administered upon recruitment till 5 days after delivery. The Edinburgh Postnatal Depression Scale (EPDS) was administered via phone or online survey at 6 to 10 weeks postdelivery. Data from the first 93 patients was analyzed using Spearman Correlational analysis. Linear regression analysis was also performed to predict postnatal EPDS total scores based on CSI total scores. 

Results and Discussion: 
A weak correlation was found between the total scores of CSI and EPDS (R=0.248). Linear regression analysis revealed that EPDS total score increased by 0.13 for every increase in CSI total score (p=0.0143). 

Conclusion: 
Parturients with features of central sensitization may be at risk of developing postnatal depression. Larger studies are needed to examine the strength of this association after adjusting for other risk factors associated with postnatal depression. Clinical practice may be directed towards modulating central sensitization in high-risk individuals to curtail the incidence of postnatal depression if the strength of this association can be validated. 

References: 
1. Neblett R, Cohen H, Choi Y, Hartzell MM, Williams M, Mayer TG, et al. The Central Sensitization Inventory (CSI): establishing clinically significant values for identifying central sensitivity syndromes in an outpatient chronic pain sample. J Pain. 2013 May;14(5):438–45. 
2. Ang DC, Chakr R, France CR, Mazzuca SA, Stump TE, Hilligoss J, et al. Association of nociceptive responsivity with clinical pain and the moderating effect of depression. J Pain. 2011 Mar;12(3):384–9.
3. Eisenach JC, Pan PH, Smiley R, Lavand’homme P, Landau R, Houle TT. Severity of Acute Pain After Childbirth, but not Type of Delivery, Predicts Persistent Pain and Postpartum Depression. Pain. 2008;140(1):87-94.
4. Eller-Smith OC, Nicol AL, Christianson JA. Potential Mechanisms Underlying Centralized Pain and Emerging Therapeutic Interventions. Frontiers in Cellular Neuroscience. 2018;12:35.

01 / Parturients with more central sensitization may have increased risk of postnatal depression: a preliminary analysis