Table 2 Descriptive characteristics of participants’ semen parameters between 2009 and 2019.

From: A longitudinal study of semen quality among Chinese sperm donor candidates during the past 11 years

Year

n

Sperm concentration (million/mL)

Total sperm count (million)

Progressive motility (%)

Total motility (%)

Median [IQR 25–75]

Median [IQR 25–75]

Median [IQR 25–75]

Median [IQR 25–75]

2009

907

62.0 [40.0–77.0]

160.0 [100.0–225.0]

54.0 [40.0–64.0]

60.0 [48.0–69.0]

2010

408

60.0 [40.0–74.0]

157.0 [104.5–219.0]

60.0 [45.25–65.0]

65.0 [50.0–70.0]

2011

981

56.0 [39.0–73.0]

150.0 [80.0–210.0]

50.0 [40.0–65.0]

60.0 [45.0–70.0]

2012

751

53.0 [30.0–72.0]

138.0 [80.0–195.0]

50.0 [40.0–65.0]

60.0 [45.0–70.0]

2013

3,258

51.0 [31.0–68.0]

126.0 [75.0–200.0]

50.0 [35.0–65.0]

60.0 [45.0–70.0]

2014

5,446

50.0 [30.0–65.0]

120.0 [70.00–190.0]

50.0 [40.0–60.0]

60.0 [45.0–70.0]

2015

3,759

47.0 [27.0–62.0]

118.0 [63.0–183.0]

50.0 [40.0–62.0]

60.0 [45.0–70.0]

2016

2,523

45.0 [25.0–60.0]

111.0 [61.0–171.1]

49.0 [39.0–59.0]

59.0 [49.0–69.0]

2017

2,343

42.0 [22.0–57.0]

100.0 [60.0–160.0]

48.0 [38.0–58.0]

57.0 [42.0–64.0]

2018

1,412

34.0 [24.0–55.0]

80.0 [50.0–166.0]

41.0 [31.0–51.0]

54.0 [40.0–60.0]

2019

2,148

32.0 [12.00–54.0]

80.0 [25.0–135.0]

40.0 [21.0–43.0]

46.0 [30.0–49.0]

Rates of decrease per year

 

3.9

4.2

2.5

1.9

  1. Rates of decrease per year were assessed using multiple regression analysis adjusting for age, BMI, and days of sexual abstinence.
  2. IQR interquartile range.