Sitz baths are safe in pregnancy and genuinely help an anal fissure, since warm water relaxes the muscle spasm around it and eases pain after passing stool. Constipation is the real driver behind the fissure coming back, and pregnancy tends to make that harder to control.
Next Steps
Sit in warm plain water for 10 to 15 minutes, a couple of times a day and after a bowel movement. Add more fibre, fruit and water through the day, and ask your obstetrician about a pregnancy-safe stool softener if it continues.
Health Tips
See your obstetrician or a general surgeon if you notice bleeding, a lump, or pain that doesn't ease between sittings.