目的观察长期持续饮用奶粉对健康育龄妇女生理周期、排卵时机以及晨尿中性激素排泄水平的影响。方法招募32名健康青年女性并随机分配到两个组,分别给予不同的饮奶量,进行为期3个月经周期的饮奶实验。第一个月经周期为对照周期,第二个月经周期为饮奶周期。受试者从第二个月经周期月经来潮第4d开始每日饮奶,每日一次饮用33g(低剂量组)或55g(高剂量组)市售奶粉冲调的复原奶,持续21 d;第三个月经周期为停止饮奶的对照周期。在全部三个月经周期内,记录受试者周期长度,采用基础体温和排卵试纸测定排卵日期,多时点(第一、三月经周期第4、7、10、13、16、19和24 d,第二月经周期第4、5、6、7、9、12、15、18、21和24 d)采集晨尿样本,测定尿雌二醇、孕二醇以及肌酐浓度;将尿激素浓度随时间描绘曲线,计算至24d时的曲线下面积。结果高剂量组的三个月经周期分别平均为(29.60±3.180)、(28.87±3.021)和(29.60±2.995)d,低剂量组分别为(30.40±4.014)、(29.67±3.266)和(29.47±3.021)d,两个组的三个月经周期差异均无统计学意义,每个周期两组间差异也无统计学意义。高剂量组排卵日时间分别平均为(15.47±2.295)、(15.40±1.882)和(15.73±2.404)d,低剂量组排卵日时间为(16.93±1.624)、(15.73±2.344)和(15.47±2.200)d,两组的三个周期间差异无统计学意义,每个周期两组间差异无统计学意义。分别将第一、三周期的周期长度、排卵日时间与第二周期进行比较,其差值在两个组间差异无统计学意义。高剂量组三个周期内肌酐校正的尿雌二醇的曲线下面积分别为(7160.28±2305.52)、(6700.26±2066.67)和(6676.24±2573.89);低剂量组为(6838.21±1447.25)、(6611.33±1648.21)和(5949.24±1437.54)。高剂量组三个周期内肌酐校正的尿孕二醇的曲线下面积分别为(51.93±18.80)、(44.55±14.62)和(46.49±22.44);低剂量组为(49.25±15.68)、(48.79±15.61)和(43.45±12.77)。肌酐校正的尿雌二醇、孕二醇浓度的曲线下面积在不同剂量组、不同周期间均无统计学意义。结论 21 d内每日连续饮用日常消费量的奶粉,没有观察到对女性生理周期的显著影响,也没观察到晨尿中雌二醇、孕二醇的排泄水平的变化。 Objective To observe the effect of long-term continuous drinking of milk powder on the physiological cycle, ovulation timing and the level of urinary excretion of morning urine in healthy women of childbearing age. Methods Thirty-two healthy young women were enrolled and randomly assigned to two groups. Different amounts of milk were given to each group, and a three-month lactation test was conducted. The first menstrual cycle is the control cycle, the second menstrual cycle is the milk drinking cycle. Subjects drink daily from the 4th menstrual cramps of the second menstrual cycle and consume 21 grams of reconstituted milk prepared from commercially available powdered milk of 33g (low dose group) or 55g (high dose group) daily for 21 days. Three menstrual cycle is the control period to stop drinking milk. During all three menstrual cycles, the length of the subject’s cycle was recorded, basal body temperature and ovulation test strips were used to determine the ovulation date, and multiple time points (1st, 3rd menstrual cycle days 4, 7, 10, 13, 16, 19 and 24, The second menstrual cycle on the 4th, 5th, 6th, 7th, 9th, 12th, 15th, 18th, 21st and 24th days). Urine estradiol, Draw the curve and calculate the area under the curve at 24 days. Results The average of the three menstrual cycles in the high dose group was (29.60 ± 3.180), (28.87 ± 3.021) and (29.60 ± 2.995) d, respectively, and the low dose group was (30.40 ± 4.014), (29.67 ± 3.266) and ± 3.021) d, there was no significant difference in the three menstrual cycles between the two groups, and there was no significant difference between the two groups in each cycle. The days of ovulation in the high-dose group were (15.47 ± 2.295) and (15.40 ± 1.882) days and (15.73 ± 2.404) days respectively, and the ovulation days in the low-dose group were (16.93 ± 1.624 and 15.73 ± 2.344 and 15.47 ± 2.200) d, no significant difference between the two groups of three weeks, no significant difference between the two groups for each cycle. The length of the first cycle and the third cycle, the ovulation time and the second cycle were compared respectively. The difference between the two groups was not statistically significant. The area under the curve of creatinine-corrected urinary estradiol in the high-dose group was (7160.28 ± 2305.52), (6700.26 ± 2066.67) and (6676.24 ± 2573.89), respectively; the low dose group was (6838.21 ± 1447.25) ± 1648.21) and (5949.24 ± 1437.54). The area under the curve of creatinine-corrected urinary pregnanediol was (51.93 ± 18.80), (44.55 ± 14.62) and (46.49 ± 22.44) in the high-dose group and 49.25 ± 15.68 (48.79) in the low-dose group ± 15.61) and (43.45 ± 12.77). Creatinine-corrected urinary estradiol and pregnanediol concentrations under the curve of the area in different dose groups, different weeks were not statistically significant. CONCLUSIONS: Daily consumption of powdered milk, which is daily consumed continuously for 21 days, did not show any significant effect on the female’s menstrual cycle and did not observe changes in the excretion of estradiol and progesterone in morning urine.