OBJECTIVE: This study intended to evaluate rectal and anal straining pressures in primigravidae, at simulated defecation. METHODS: The present study is based on 60 women from de Antenatal Care of Santa Casa de Misericórdia - São Paulo. Patients were divided into four groups of 15: a) Control group: nuligravidae; b) 1st trimester primigravidae; c) 2nd trimester primigravidae; d) 3rd trimester primigravidae. All patients underwent rectal and anal measurements to obtain: a) Resting rectal pressure; b) Straining rectal pressure; c) Minimal straining anal pressure. RESULTS: Data was analyzed using statistical methods and reached, the same results: it was observed that the straining rectal pressure decreased from 53.9 ± 17.9 in control group a to respectively 36.3 ± 19.6 in group b, 38.1 ± 16.2 in group c, 30.5 ± 17.0 in group d, of pregnant women. The minimal anal straining pressure decreased from 46.9 ± 1.6 in the control group a to 37.5 ± 15.5 in group b, 32.2 ± 6.2 in group c , 32.9 ± 8.7 in group d, during pregnancy. CONCLUSION: Straining rectal and anal pressures both decreased during pregnancy in comparison with the control group, counterbalancing one another to reach a new point of equilibrium during defecation.
Pregnancy; Constipation; Motilin anal and rectum