Uroflowmetric observations in pregnancy

Uroflowmetric studies were performed on 752 antepartum patients at various stages of pregnancy and 153 patients 6 weeks postpartum. The mean voided volume in the antepartum group (203.4 ml) was significantly lower ( P < .001) than that of the postpartum group (261.1 ml). In the antepartum group, the data suggests a significant decrease in voided volume in the third trimester. The uroflowmetric parameters (FT, Q‐max, T‐Q‐max) studied were observed to be directly related to voided volumes. This is an observation known in the nonpregnant female. Presenting stations of zero and above do not appear to influence the uroflowmetric parameters. Subjective increases in frequency of urination during pregnancy are correlated with objective decreases in the volumes voided, and the converse is also found to be true. The contributory roles of the mechanical and endocrinological factors on micturition in pregnancy are discussed. It appears that the predominant factor may be mechanical.