Background: Pregnant women may experience constipation for the first time or their existing constipation symptoms increase in severity during pregnancy.Aim: To compare the effect of progesterone versus diet modification in the treatment of constipation during pregnancy.Subjects and Methods: Women aged ≥18 years with functional constipation according to the Rome III criteria from obstetrics outpatients’ clinic and midwife practices included in this study. Participants divided into two groups; control group managed with diet modifications and study group pregnant women with threatened miscarriage and advised to take vaginal progesterone ≥1 week. Participants completed a nonvalidated questionnaire created by the authors during the whole week before intake of progesterone or diet modifications and after treatment phase. Independent Student’s t‑test and Chi‑square (X2) test were used for statistical analysis to compare between two studied groups. Primary outcome measures; change in defecation frequency.Results: Sensation of anorectal obstruction and sensation of incomplete evacuation were significantly less in Group B (progesterone therapy) compared to Group A (diet modification) (54% [154/281] and 62.98% [177/281] vs. 89.76% [614/684] and 91.08% [623/684], respectively) (P = 0.04 and 0.03, respectively). Straining during defecation and manual maneuvers to facilitate evacuation were significantly less in Group B compared to Group A (63.7% [179/281] and 19.9% [56/281] vs. 94.59% [647/684] and 86.54% [592/684], respectively) (P < 0.01 and 0.02, respectively). Episodes of abdominal pain and presence of reflux episodes were also significantly less in Group B compared to Group A (18.5% [52/281] and 17.43% [49/281] vs. 84.11% [589/684] and 75% [513/684], respectively) (P = 0.01 and 0.03, respectively). Conclusions: Estrogen, rather than progesterone, may be a detrimental factor of constipation during pregnancy via decreased bowel movement. Progesterone therapy seems to be effective in the treatment of functional constipation during pregnancy. A randomized placebo controlled trial is required to confirm the data of this study.KEY WORDS: Constipation, diet modification, pregnancy, progesteron
