Another 1/3 of cases is infertility due to man.
Factors altering sperm parameters
Low count/below 20 million sperms per ml of sperm, low sperm mobility (inability of the sperm to satisfactorily proceed and meet the egg for fertilisation), abnormal sperm morphology resulting in the inability to fertilise the egg may explain male infertility.
Although male age will not set obstacles, it is very likely that due to:
inflammations (e.g. parotid, prostatitis, epididymitis, and orchitis),
genetic anomalies (obstructive and non-obstructive azoospermia),
injuries to genitals,
vas deferens obstruction or malformation,
cryptorchism,
impotence or failed ejaculation (high FSH, excessive prolactin),
immune factors,
high temperatures (warm bath, sauna, hot workplaces and anything that causes an increase in scrotal temperature daily habits (smoking, alcohol, drug abuse, use of anabolic steroids), intense stress or long-term sexual abstinence, low-quality sperm is produced, which is not able to normally fertilise the partner’s egg.