Planning a family while receiving antifungal treatment is possible, but discussing medication safety with your specialist is important.
Can you safely have a baby while receiving treatment for aspergillosis? What happens if the father is taking antifungal medication? And what should women know before becoming pregnant?
These are important questions for people living with aspergillosis, particularly those receiving long-term antifungal treatment.
The encouraging news is that having aspergillosis does not automatically prevent someone from becoming a parent. However, some antifungal medicines can present risks during pregnancy, and evidence about their effects on fertility is sometimes limited.
Understanding the difference between treatment taken by the father and treatment taken by the mother is particularly important.
A patient’s question: Can we have a baby while I take Cresemba?
A patient recently asked us:
I have invasive aspergillosis and have been taking Cresemba (200 mg daily) for about a year. My results are good, and my wife and I would like to have a baby. Is pregnancy a problem?
This is a very reasonable question, and there is some encouraging information, although important uncertainties remain.
Cresemba is the brand name for isavuconazole, an antifungal medicine used to treat serious fungal infections, including invasive aspergillosis.
When the father is taking Cresemba, there is currently no established evidence that paternal exposure causes birth defects. However, studies directly examining pregnancy outcomes in couples where the father takes isavuconazole are lacking.
The official prescribing information tells us that:
- Animal studies did not demonstrate impaired fertility in male or female rats.
- Standard laboratory testing did not identify a significant potential for the medicine to damage genetic material.
- There are no adequate human studies establishing its effects on fertility.
- The prescribing information does not specify a waiting period before conception for men taking Cresemba.
These findings are encouraging, but they do not establish that paternal exposure is completely without risk.
A specialist medicines information review undertaken at Manchester University NHS Foundation Trust in October 2026 also examined the evidence for other commonly used azole antifungals.
Its conclusion was that there are no clinical data demonstrating an impact on human male fertility from itraconazole, voriconazole, posaconazole or isavuconazole.
However, the available human evidence is limited. The absence of evidence demonstrating harm does not prove that these medicines are entirely without risk.
For someone whose invasive aspergillosis is responding well to treatment, stopping an effective antifungal medicine without medical advice could be dangerous.
The sensible next step is to discuss plans for a baby with the specialist prescribing Cresemba, rather than stopping treatment.
Why does it matter which parent takes the medication?
Medicines can affect reproduction in several different ways.
When a woman takes a medicine during pregnancy, the developing baby may be exposed to it through the placenta. Some medicines can interfere with normal fetal development.
When a man takes a medicine, the situation is different. The main questions concern whether the medicine affects sperm production, sperm quality or genetic material, and whether exposure through semen could be significant.
These are not equivalent exposures.
The UK Teratology Information Service (UKTIS), which specialises in medicine safety during pregnancy, provides information about paternal medication exposure and reproductive risks.
For most medicines, paternal exposure is not expected to cause major problems for a developing baby. However, some medicines have specific reproductive risks, and individual advice remains important.
It is therefore incorrect to assume that a medicine carrying a pregnancy warning for women necessarily poses the same risk when taken by men.
Do azole antifungal medicines affect male fertility?
Four azole antifungal medicines are commonly used to treat aspergillosis:
- Itraconazole
- Voriconazole
- Posaconazole
- Isavuconazole (Cresemba)
A specialist review by the MFT Medicines Information service examined the available evidence concerning these medicines and male fertility.
Animal studies did not demonstrate impaired male fertility with these four medicines at the exposures investigated.
Importantly, the review found no clinical data demonstrating that these medicines impair human male fertility.
It also found no evidence establishing that paternal exposure to these medicines causes birth defects.
However, direct studies involving men taking these medicines and the outcomes of subsequent pregnancies are lacking. This limits how confidently we can assess their reproductive safety.
Reports of sexual dysfunction, sperm disorders and fertility problems have occasionally been submitted to medicine safety monitoring systems. Such reports are investigated, but they do not necessarily mean that the medicine caused the reported problem.
An important exception: ketoconazole
An older antifungal medicine, oral ketoconazole, is known to affect male reproductive hormones.
At higher doses, it can reduce testosterone production and has been associated with reduced sperm counts and, occasionally, absence of sperm in semen.
However, these effects should not be assumed to apply to itraconazole, voriconazole, posaconazole or isavuconazole.
The important message is that there is no demonstrated effect on human male fertility from the four commonly used azoles reviewed, but the available human evidence remains limited.
Men who are planning a family should discuss their treatment with their specialist, particularly if they have concerns about fertility or experience sexual side effects.
What about women taking antifungal medicines?
This requires considerably more caution.
Several antifungal medicines used to treat aspergillosis have warnings concerning their use during pregnancy. Some have caused developmental abnormalities in animal studies, while information about human pregnancies may be limited.
For example, Cresemba is generally not recommended during pregnancy. Its prescribing information allows for use in severe or potentially life-threatening fungal infections when the expected benefit outweighs the possible risks to the baby.
Other antifungal medicines, including itraconazole, voriconazole and posaconazole, also have important pregnancy precautions. The recommendations differ between medicines.
This does not mean that women with aspergillosis cannot become pregnant. It means that treatment should ideally be reviewed before conception, so that the safest appropriate plan can be agreed.
Women taking antifungal medication who are considering pregnancy should discuss their plans with their clinician as early as possible.
This allows time to review medicines, consider any necessary changes and ensure that the underlying fungal condition remains adequately controlled.
For serious fungal infections, controlling the infection remains essential. Stopping treatment without a suitable alternative could put the mother’s health at risk.
Further advice about individual medicines may also be available in the drug-specific patient information leaflets provided by the prescribing team.
Does aspergillosis itself affect fertility or pregnancy?
There is no established evidence that aspergillosis routinely causes infertility.
However, the effect of the illness on someone’s general health may be important.
Aspergillosis covers several different conditions, including:
- Allergic bronchopulmonary aspergillosis (ABPA): An allergic inflammatory condition affecting the airways, often in people with asthma.
- Chronic pulmonary aspergillosis (CPA): A long-term fungal lung infection that may require months or years of treatment.
- Invasive aspergillosis: A serious infection, often occurring in people whose immune systems are weakened.
The implications for pregnancy will differ depending on the condition, lung function, severity of illness and medicines being used.
For women with significant respiratory disease, pregnancy places additional demands on breathing and circulation. Planning ahead with the respiratory team and maternity specialists is particularly valuable.
Some people with aspergillosis also take corticosteroids, immunosuppressants or other medicines that need reviewing before pregnancy.
What should you do if you are planning a baby?
1. Tell your specialist that you are planning a family
Whether you are male or female, this gives your clinical team an opportunity to consider your current treatment and whether any changes are necessary.
Women taking antifungal medicines should raise the subject as early as possible, ideally before conception.
2. Review all your medicines
This includes antifungals, steroids, immunosuppressants and any other prescribed or over-the-counter medicines.
The reproductive safety of each medicine may be different, and pregnancy warnings do not necessarily mean the same thing for mothers and fathers.
3. Do not stop antifungal treatment without medical advice
For some people, treatment is essential to prevent a serious infection from progressing or returning.
Stopping an effective medicine may carry considerably greater risks than continuing treatment under specialist supervision.
4. Ask about the evidence for your particular medicine
Some medicines have been studied extensively during pregnancy, while others have very little human evidence.
Your specialist or pharmacist can help interpret what is known, what remains uncertain and whether any precautions are appropriate.
5. Plan ahead wherever possible
A planned pregnancy provides time to review treatment, optimise health and arrange any additional specialist support.
Frequently asked questions
Can a man taking Cresemba father a baby?
There is currently no established evidence that paternal treatment with Cresemba (isavuconazole) causes birth defects or impairs male fertility.
Animal studies have not demonstrated impaired male fertility, but direct human studies of fertility and pregnancy outcomes following paternal exposure are lacking.
Men planning a family should discuss their treatment with their specialist rather than stopping it themselves.
Does taking antifungal medication make you infertile?
Not necessarily.
There are no clinical data demonstrating impaired human male fertility from itraconazole, voriconazole, posaconazole or isavuconazole, although human studies are limited.
Oral ketoconazole is an important exception because it can affect testosterone production and sperm counts.
Taking an antifungal medicine does not automatically mean someone is infertile.
Can antifungal treatment taken by the father harm the baby?
The MFT Medicines Information review found no evidence establishing an increased risk of birth defects following paternal exposure to itraconazole, voriconazole, posaconazole or isavuconazole.
However, direct human studies are lacking, so a risk cannot be completely excluded.
Risks associated with a woman taking a medicine during pregnancy should not automatically be assumed to apply when the father takes it.
Should I stop my antifungal medicine before trying for a baby?
Not without medical advice.
The consequences of stopping treatment may be serious. Whether treatment needs changing depends on the medicine, which partner is taking it, and the underlying fungal disease.
What if I become pregnant unexpectedly while taking an antifungal?
Contact your prescribing specialist and maternity team promptly for an individual assessment.
Do not make treatment changes on your own. A medicine carrying a pregnancy warning does not automatically mean that harm has occurred.
Can someone with chronic pulmonary aspergillosis have a healthy pregnancy?
It may be possible, but individual circumstances matter.
Lung function, disease activity, other health conditions and medication safety should all be considered before pregnancy.
Planning with your respiratory specialist and maternity team can help identify the safest approach.
Where can I find reliable information?
The following resources provide authoritative information about medicines and pregnancy:
- UK Teratology Information Service (UKTIS) – Specialist evidence-based guidance on medicines and pregnancy, including paternal medication exposure.
- BUMPS – Best Use of Medicines in Pregnancy – Patient-friendly information from UKTIS.
- Cresemba prescribing information – Official UK information about isavuconazole, including fertility and pregnancy precautions (section 4.6).
This article also incorporates the findings of a specialist medicines information review undertaken by Manchester University NHS Foundation Trust in October 2026 concerning azole antifungals, male fertility and paternal exposure.
The important message
Having aspergillosis or receiving antifungal treatment does not automatically mean that you cannot have children.
For men taking itraconazole, voriconazole, posaconazole or isavuconazole, there are currently no clinical data demonstrating impaired human male fertility or birth defects caused by paternal exposure. However, the lack of direct human studies means that uncertainty remains.
For women receiving antifungal treatment, pregnancy planning requires particular care because some medicines may affect a developing baby. Discuss your plans with your clinician as early as possible.
In either situation, discussing family plans with your specialist before conception is the safest approach.
You should not have to choose between protecting your health and planning a family without first understanding the available options.
This article provides general information and is not a substitute for individual medical advice. Decisions about pregnancy and antifungal treatment should be made with your clinical team.
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