The effect of doxycycline in infertile couples with male accessory gland infection: a double blind prospective study

Male accessory gland infection (MAGI, epididymo-prostato-vesiculitis) with abnormal semen quality was rarely the only abnormality in infertile couples since it occurred in no more than 1.6% of 2871 couples evaluated in 7 centres during a 3-year period. Both partners of 33 infertile couples with no other demonstrable abnormality than abnormal semen and MAGI consented to participate in a double blind trial and were treated with either doxycycline, 100 mg/day for 1 month (20 couples) or placebo (13 couples). Follow-up during a total of 175 couple-months included semen analysis and the recording of pregnancy. Pregnancy occurred in 2 of the doxycycline-treated couples (10%) and in 1 of the placebo treated couples (8%), corresponding with conception rates per month of 1.9% and 1.5%, respectively. Sperm motility and, to a lesser extent, morphology showed improvement in both groups. Evidence of infection, namely increased numbers of white blood cells and positive sperm culture, disappeared in both the doxycycline-treated and placebo group. It is concluded that features of MAGI in semen may regress spontaneously and are not influenced by the doxycycline treatment. The concomitant improvement of sperm motility and morphology still does not seem to enhance the probability of conception.