Sex/Fertility Questions relating to Chemo (Temozolomide)

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My (male) partner is currently undergoing chemotherapy (temozolomide) for a brain tumour.

We have been vaguely told that we must use barrier contraception to avoid a) risk to me from possible transmission of chemo into semen, and b) risk to a potential unborn child if I were to get pregnant.

No-one has yet been able to clarify what exactly these risks are, and how long they might last after he stops taking chemo. Some sources say the "risks" (whatever they might be) last 2 days, some 2 years.

So... In terms of health risks to me:

1) What (if any) are the risks to me, if I come into contact with potentially chemo (temozolomide)-tained semen?

2) How long might my partner's semen continue to convey this risk?

And in terms of risk to a child if I were to get pregnant:

1) What risk (of disease? of spontaneous abortion? or abnormalities? etc.) is sperm produced whilst/after taking chemo (temozolomide) thought to convey to any baby conceived?

2) Is this risk KNOWN to exist (i.e. documented cases, anecdotal evidence, clinical tests); or a hypothetical risk (i.e. no examples of harm, but as untested medics err on the side of caution)?

3) If there is a KNOW risk, what percentage increase does this risk entail compared to a normal pregnancy? 

4) For how long after finishing chemo would these risks last?

In case it makes any difference, I'm 30, and my partner is 33.

Any answers (especially with links to medical back-up), or pointers as to where we might find information, would be greatly appreciated!!!!



  • Hi Susan, We have no experience of temozolomide but there is an information page at Cancer Research uk (cruk) about it mentioning fertility issues which you can find here.

    These questions would be better asked of your partners onco team as they will have all the relevant information.

    Considering your partners young age did they not mention anything about storing semen prior to starting temozolomide in case of fertility / impairment issues - or are they confident his fertility would only be short term minimally affected ?

    Macmillan has this page covering cancer treatment and fertility but it generalises and covers all types of treatment albeit individually. There is additional information on the left hand sub menu.

    Hope this is of some help until you get more replies from those in the group who can help further.

    George & Jackie (breast group)

  • FormerMember
    FormerMember in reply to Dreamthief

    Hi Jackie and George, and thank you very much for your reply!

    We have spoken on a number of occasions with various medics re: the safety of conceiving whilst on/after taking Temozolomide, but the answers we have been given so far have been vague (and sometimes contradictory). On most other topics, the medics have been happy to give us quite in depth info (and pointers for our own research), so the muddy waters on this topic lead me to think there may be be a limited understanding of the effects of the drug (or all chemo drugs?) on fertility... Although I'm hoping it's just a case of continuing to dig!!

    Issues of the safety of conceiving aside for a moment, we've been told that it's very hard to predict what the impact on our ability to conceive will be: anything from a temporary lowering of sperm count, to permanent infertility. 

    My partner did store one "sample" of sperm before beginning treatment, but we understand this is only likely to be enough for 5 rounds of IVF. With the relatively low success rate of this type of fertility treatment (averaging 1 full term pregnancy per 5 cycles of IVF, I believe?), and the fact that in our area the NHS will only fund 2 rounds per couple (and we can't afford private treatment), I don't hugely rate our chances of success with the stored sperm.... 

    Additionally, IVF = MORE HOSPITALS. Ugh. 

    If possible (and safe), I have to say the natural route is a lot more appealing!!! 

    I have learnt a bit from the links you sent me, however, so thank you again. 

    Although most articles seem to suggest waiting 2 years post treatment, the Cancer Research link you posted specifically re: Temozolomide ( ) says best to wait 6 months post treatement, so maybe that indicates there's something they know about TMZ in particular that we don't yet!! 

    Also, if anyone else is reading this looking for similar answers, I found a useful link ( ) which goes some way to explaining what these mysterious "risks to the unborn child" are: (some?) chemo drugs can affect the DNA of the sperm, and could cause abnormalities in the foetus. They don't know how long these changes to DNA could last, but they think definitely no more than 2 years.... (Or 6 months for TMZ if the Cancer Research page is correct!? AGGGHHHHH!!!)

  • FormerMember

    Hello Susan, similar position here! My husband and I are 33 and have been having ivf due to the chemo - so far unsuccessful sadly and wondering when can try again naturally. The ivf clinic says test semen after 6 months but they recommend waiting a year, and the oncologist says wait 6 months. As you say, documented info hard to find as no one experiments with this kind of thing. We were going to start testing semen after 6 months I think although haven't got to that decision point yet. Finding the whole thing pretty traumatic - all my hopes for a healthy husband and small family seem to be up in the air in one fell swoop - few people seem to know how it feels to juggle all those emotions. Cx

  • FormerMember

    Hi, I know this is a slightly old post but I wanted to tell you my story in case it helped and brought some hope. So here's the short version: My husband was diagnosed with a brain tumour in April 2012 which was later found to be GBM. He started radiotherapy and tmz in December 2012 and had the usual 6 round of tmz. We started trying to conceive in February 2014 and to our total and utter shock got pregnant straight away!! 9(ish) months later and I gave birth to our beautiful baby boy in October! I was induced 3 weeks early as he had stopped growing in utero but I don't think this would have been anything to do with my husband's treatment and (until that point) my pregnancy was not considered high risk. Our little miracle is just over 14 weeks old and he's perfect.

    We have been through hell over the past 3 years and we have just had the news that my husband's tumour is growing and we are pretty much at last chance saloon treatment wise. Having our son keeps us focused on the future and as positive as we can be. We are very lucky to have him in our lives! 

    I hope that your partners' treatments are successful and wish you all the best in conceiving your little miracles too! Xx

    PS. I was 31 and hubby was 29 when we conceived

  • FormerMember


    I know this post is old but I wanted to know how you went? Did the medical team provide any answers. 

    We are at this point now too, a few weeks before intense chemo starts again after another operation and wondering if we should give it one last shot (sperm is frozen but this is likely our only time to conceive again naturally)

    It's likely he's infertile anyway, but what if I did fall pregnant (it's only been 6w since his last tmz)? I cannot find ANYTHING about what birth defects might occur, or any stories of people who have conceived so close to chemo. Surely there are people out there?! I know the recommendation is to not do it but I cannot find any research! 

    I hope all is going well Susan. 

  • FormerMember
    FormerMember in reply to FormerMember


    My husband and I are in a similar situation. He's been on TMZ every 4-6 weeks for eight years. We've been married a little over a year and have been trying to conceive since our wedding. I just finished my second round of clomid to help me conceive and we just meet a new oncologist. When we told him about trying to conceive he told us to wait until my husband is off TMZ for at least 6 months. I just broke down and cried because he's likely not going to ever be off chemo of some sort for that long. I'm 37 so my time is running out.  Not to mention that I could be pregnant right now and not know it yet. It's all just emotionally draining.

    Anyway, I was very happy to find this thread. Not that I am happy others are in the same situation but it's nice not to be alone.

  • FormerMember
    FormerMember in reply to FormerMember

    HI RADandRDD,

    My husband is in the same situation.... Will probably never be off the TMZ. He started taking it back in 2015, went off it for almost 9 months and the cancer came back as stage 4. He started TMZ again in November 2017. Has your husbands situation changed? Have you gotten anymore information about conceiving? I was thinking of taking him to a fertility clinic to have them run an analysis on his sperm to see if maybe there are some that are normal. such a heartbreaking thing. Them having cancer and then not being about to have children

  • FormerMember
    FormerMember in reply to FormerMember

    It's so funny that today is the day I got a message (my first message) from this site. My husband is currently in the recovery room waking up from his fourth brain surgery.  A few months ago they took him off of tmz and put him on lomoustine. Which he had to sign a contract saying he wouldn't have children. So I've just kind of accepted the fact that we won't be having children. This surgery was able to get rid of some of the tumor but not all of it because it's so entwined. He's also been using the Optune-novocure treatment since September. I wish you luck.

  • FormerMember
    FormerMember in reply to FormerMember


    I know your question wasn’t aimed at me but thought I’d update too.

    When we found out hubby was having chemo we asked the doctor if he should freeze sperm (she didn’t ask us which makes me really angry- it should be standard). 

    Everything I read (and drs I spoke to) said not to conceive naturally until 6 weeks after tmz. Sadly that time never came for us, and my husband passed in September. Brain cancer is a bitch.

    I hope you have a break somewhere so you can freeze some too as I will still be able to have another child with my husband even though he’s gone. I would maybe get an appointment at a fertility clinic see if you can have some sperm tested and then frozen if safe.

    Best of luck x

  • FormerMember
    FormerMember in reply to FormerMember


    I just came across this thread, and see that it’s been inactive for awhile but figure posting is worth a shot. 
    It’s comforting to read other’s accounts of their experience (and confusion) with fertility and brain cancer treatment. 
    My husband (38) and I (34) feel extremely lucky to have two healthy children (2.5 and 5). Prior to his BC diagnosis (Anaplastic astrocytoma) last fall, we had planned to have a third child. His oncologist spoke to us about banking sperm prior to beginning treatment. At the time, we were so overwhelmed with everything and eager to begin treatment that we did not follow through.  Fast forward almost a year, my husband has been tolerating treatment (Temodar) quite well. He is on the maintenance schedule and has about 6 months left.  I just learned that I am pregnant, and keep vacillating between excitement and anxiety. A part of me feels that it was meant to be (we were not trying) but I’m worried about the effects of Temodar.  There is so little info out there, and feedback that we’ve gotten from our doctors has been so mixed... we would desperately like to be excited about this new pregnancy, but are having reservations. Would love to hear from someone who has given birth to a baby exposed to Temodar.  thanks for reading and best wishes to everyone going through this battle.