Can Ureaplasma Urealyticum and Mycoplasma Hominis affect fertility?


my husband and I have been through a 7 year battle to get pregnant, seeing both NHS and Private consultants. We have been diagnosed with ‘unexplained fertility’

statistics below:

Husband – 40
Wife – 32
1st IVF – 18 eggs, Zero fertilisation
2nd ICSI – 29 eggs, 7 X blastocysts. One miscarriage at 5 weeks, only a sac and no baby.
3rd ICSI – 18 eggs, 5 X blastocysts. One missed miscarriage at 5 weeks.
4th ICSI – 12 eggs, 3 X blastocysts. Not yet used.

My husband is also a non identical twin and his twin brother is also struggling to get pregnant with his wife. They have been informed they both have ‘Ureaplasma Urealyticum and Mycoplasma Hominis’ which requires antibiotics to eliminate this bacteria.

We have been informed that as my husband is a twin, he may carry the same.

Have you heard of this before and does it affect your fertility success?

Kind Regards,


Dear A.,

I am inclined to think that this is less of a problem than many doctors believe.  There are nearly 500 publications of research on these organisms and the possible association with infertility.  And it is frequently claimed that they are associated with female infertility.  But when we at Genesis did a great deal of research in the 1970s – Gosh what a long time ago – we failed to demonstrate that these two quite common organisms caused serious inflammation or infertility in over one hundred patients we studied extensively. All these patients were studied in great detail with measurements of blood antibodies, the bacteria they carried in the vagina and cervix, scrapings from the uterus and the Fallopian tubes, and culture of the fluid from the pelvis. This was after inspection at laparoscopy to confirm the presents or absence of scarring from any infections. It was striking that there was no good correlation between mycoplasma infection and changes in the tubes or uterus in these infertile women.

So whilst it is said that they cause pelvic inflammatory disease, I think that hard evidence is lacking.  Because Ureaplasma and Mycoplasma are slightly puzzling organisms I think the general thing that happens sometimes is that they get blamed for a whole lot of dubious diagnoses. And whenever sexual transmission is mentioned the tendency is for some experts to throw up their hands in horror. It is clearly true they are frequently transmitted sexually but it is much less clear whether this is at all important in infertility.

I am not so sure about these infections in males as I have no personal experience, but I am still doubtful whether sperm count and function are really depressed much as a result of these infections in men.

By the way, you mention your IVF results – it does seem as if you are very sensitive to the stimulatory drugs and clearly too much of them may result a large number of eggs to be collected which may seem encouraging but they may not be well-primed genetically or adequately matured.  It’s possible you may need to have doses of these injections monitored very closely. Ideally, regular oestrogen measurements as well as scans may help to improve you response to your treatment.

I hope this is helpful

Best wishes

Robert Winston