Polyethylene glycol compared to lactulose for constipation in pregnancy: A randomized controlled trial

Victoria Ivy Raj; Azyyati Hassan; Nurulashikin Hanafiah; Jerilee Mariam Khong Azhary; Boon Kiong Lim; Rahmah Saaid; Farah Gan; Peng Chiong Tan

doi:10.1002/ijgo.15431

Polyethylene glycol compared to lactulose for constipation in pregnancy: A randomized controlled trial

Int J Gynaecol Obstet. 2024 Feb 23. doi: 10.1002/ijgo.15431. Online ahead of print.

Authors

Victoria Ivy Raj¹, Azyyati Hassan¹, Nurulashikin Hanafiah¹, Jerilee Mariam Khong Azhary¹, Boon Kiong Lim¹, Rahmah Saaid¹, Farah Gan¹, Peng Chiong Tan¹

Affiliation

¹ Department of Obstetrics and Gynecology, Faculty of Medicine, University Malaya, Jalan Profesor Diraja Ungku Aziz, Kuala Lumpur, Malaysia.

PMID: 38391250
DOI: 10.1002/ijgo.15431

Abstract

Objective: To compare polyethylene glycol 4000 versus lactulose in chronic constipation during pregnancy.

Methods: Women at 28-32 weeks' gestation attending antenatal clinic for routine care were screened using the Rome IV chronic constipation criterion. Eligible women were approached and consented. Participants were randomized to oral polyethylene glycol (10 g/day) or lactulose (10 g/day) for 4 weeks. A bowel movement diary was kept and outcomes using the Patient Assessment of Constipation Symptoms questionnaire (PAC-SYM), Patient Assessment of Constipation Quality of Life questionnaire (PAC-QoL) and Bristol Stool Form Scale (BSFS), which were evaluated at the start and end of the four-week period. Relative risks (RR) were determined for the coprimary outcomes of complete spontaneous bowel movement (CSBM) and PAC-SYM mean score improvement (decrease in score of >1 from the baseline).

Results: A total of 4323 women underwent screening, of which 780 fulfilled the Rome IV criterion, and 360 consented to participate (180 randomized to PEG and lactulose, respectively). Data from 247 women who completed the study were analyzed. CSBM was achieved in 107/124 (86.3%) versus 102/123 (82.9%) (RR 1.04, 95% CI: 0.93-1.16, P = 0.464) for PEG and lactulose trial arms, respectively. PAC-SYM mean score improvement was 62/118 (52.5%) in the PEG arm versus 44/118 (37.3%) in the lactulose arm (RR 1.40, 95% CI: 1.05-1.88). Of secondary outcomes, a significant difference was found in favor of PEG, with respect to PAC-SYM abdominal symptoms subscale, normal stool versus loose stool consistency and side effects of vomiting and diarrhea. After controlling for parity, baseline PAC-SYM, PAC-QoL scores, characteristics different at baseline, only diarrhea and loose stools remained significant.

Conclusion: Both PEG 4000 and lactulose are effective laxatives in pregnancy with similar performance after adjusted analysis. Diarrhea and loose stools are less frequently reported with PEG.

Keywords: constipation; diarrhea; lactulose; macrogol; polyethylene glycol; pregnancy.