Table 2.

Comparison of ultrasonographic measurements among groups.

	Group 1, control n=50	Group 2, mild pain n=50	Group 3, moderate pain n=50	Group 4, severe pain n=50	P value
Uterine corpus longitudinal axis (mm)	45.60 ± 4.78a	44.76 ± 2.75a	46.08 ± 4.77a	45.94 ± 3.41a	0.359
Uterine corpus transverse axis (mm)	33.02 ± 2.41a	33.32 ± 2.18a	32.46 ± 2.13a	32.82 ± 2.25a	0.279
Uterine cervix longitudinal axis (mm)	31.94 ± 2.04a	32.10 ± 1.60a	31.66 ± 1.90a	32.46 ± 1.34a	0.369
Anterior uterocervical angle	146.8 ± 6.0a	143.3 ± 7.3a	121.2 ± 7.3b	101.9 ± 9.2c	0 < 001

Note. BMI, body mass index; PD, primary dysmenorrhea. Superscript numbers indicate the absence (a) or presence (b,c) of statistically significant differences. The Minitab®16 statistical program (Minitab Inc., State College, PA, USA) was used to perform the statistical analysis. The Shapiro–Wilk test was used to evaluate the normality assumption of the data and Levene's test was used to assess the variance homogeneity assumption. Values are expressed as mean ± standard deviation. Parametric comparisons were made via t-test or z-test, and nonparametric comparisons were made via Mann–Whitney U test. P < 0.05 was considered statistically significant.