Table 4. Reproductive characteristics of women according to age at natural menopause.
| Characteristics | Age at natural menopause (years) | Ptrend | ||||
|---|---|---|---|---|---|---|
| ≤40 | 41–44 | 45–49 | 50–52 | ≥ 53 | ||
| Number of women N (%) | 581(3.40) | 1152 (6.75) | 7559 (44.27) | 5432 (31.81) | 2352 (13.77) | |
| Age at menarche (years) N (%) | <0.001 | |||||
| ≤12 | 28(4.82) | 44(3.82) | 155(2.05) | 129(2.38) | 44(1.87) | |
| 13–14 | 83(14.29) | 246(21.35) | 1238(16.38) | 823(15.15) | 316(13.43) | |
| 15 | 134(23.06) | 257(22.31) | 1691(22.37) | 1219(22.44) | 500(21.26) | |
| 16 | 105(18.07) | 230(19.97) | 1695(22.42) | 1281(23.58) | 563(23.94) | |
| ≥17 | 231(39.76) | 375(32.55) | 2780(36.78) | 1980(36.45) | 929(39.50) | |
| Number of live births N (%) | 0.51 | |||||
| ≤1 | 59(10.15) | 113(9.81) | 635(8.40) | 326(6.00) | 75(3.19) | |
| 2 | 191(32.87) | 462(40.10) | 3209(42.45) | 2509(46.19) | 966(41.07) | |
| ≥3 | 315(54.22) | 564(48.96) | 3658(48.39) | 2560(47.13) | 1299(55.23) | |
| Age at first birth (years) N (%) | 0.49 | |||||
| <20 | 194(33.39) | 415(36.02) | 2650(35.06) | 2018(37.15) | 956(40.65) | |
| 20–24 | 315(54.22) | 624(54.17) | 4148(54.87) | 2884(53.09) | 1235(52.51) | |
| 25–29 | 48(8.26) | 92(7.99) | 628(8.31) | 434(7.99) | 130(5.53) | |
| ≥30 | 7(1.20) | 5(0.43) | 63(0.83) | 57(1.05) | 18(0.77) | |
| Number of spontaneous abortion N (%) | 0.08 | |||||
| 0 | 534(94.51) | 1095(96.14) | 7060(94.11) | 5112(94.75) | 2207(94.32) | |
| 1 | 24(4.25) | 35(3.07) | 365(4.87) | 232(4.30) | 115(4.91) | |
| ≥2 | 7(1.24) | 9(0.79) | 77(1.02) | 51(0.95) | 18(0.77) | |
| Number of induced abortion N (%) | 0.61 | |||||
| 0 | 349(61.77) | 635(55.75) | 4276 (57.00) | 3077 (57.03) | 1335(57.05) | |
| 1 | 168(29.73) | 389(34.15) | 2491(33.20) | 1794(33.25) | 784(33.50) | |
| ≥2 | 48(8.50) | 115(10.10) | 735(9.80) | 524(9.72) | 221(9.45) | |
Differences between the two menopausal age groups (≤ 44 years and ≥45 years) were compared using linear-by-linear association chi-square test.