on October 22, 2025
What are the most common causes for infertility?
Infertility can have many causes, and in 1 in 4 people, no specific cause is found. Lifestyle factors such as being older, being underweight or overweight, smoking, drinking too much alcohol and stress can all increase your risk of infertility. In women, common causes include problems with ovulation (e.g. polycystic ovarian syndrome, PCOS), other hormonal imbalances (e.g. thyroid problems), premature ovarian failure (where the body stops producing eggs under the age of 40), endometriosis and fibroids. Infections such as STIs, certain medications, and using recreational drugs (e.g. cannabis) can affect fertility in both women and men.
Before trying for a baby, what are the most important health checks to have?
Before trying to conceive, it’s essential to review your general health, including checking your weight, BMI, and blood pressure, and identifying any lifestyle changes that can increase your chances of a healthy conception (e.g., stopping smoking or reducing your alcohol intake). Review any long-term conditions (e.g. diabetes or epilepsy) with your doctor and ensure any regular medications are safe to take in pregnancy. Ensure your cervical screening is up to date and that you’ve considered available vaccinations, such as rubella. It is also important to check for sexually transmitted infections such as chlamydia and gonorrhoea. It’s also recommended to start taking pre-pregnancy supplements, folic acid and vitamin D, at least a month prior to trying to conceive. Ensuring adequate intake of other key nutrients such as iron, vitamin C, omega-3 and calcium can also support reproductive health pre-pregnancy.
We’ve been trying 8 months, when should we speak to a GP and which tests should we ask for first?
It’s common not to become pregnant right away, and over 80% of women under the age of 40 will conceive within a year of trying. It’s worth speaking to a GP early in your journey, as they can assess for any risk factors for reduced fertility (e.g. smoking, being overweight, having an infection) and help to address these issues first. If you have no risk factors, are under 36, and have not conceived within a year of trying, it’s recommended to speak with your GP about further investigations. If you’re 36 or over, or have any risk factors, speak to your GP sooner. While it depends on your specific circumstances, semen analysis is usually the first test for the male partner. The female partner is often offered hormone blood tests (e.g. thyroid function, mid-luteal progesterone, FSH and LH) to check for potential ovulation problems.
Is mid-cycle spotting normal or a red flag for fertility?
Mid-cycle spotting is common and usually entirely normal and not a cause for concern. New, persistent or heavy bleeding outside of your usual period can indicate a problem such as infection or hormone imbalance.
Endometriosis runs in my family - what are the early signs to take seriously for fertility?
Endometriosis does indeed run in families and can impact fertility due to damage or scarring to the ovaries or fallopian tubes. Signs of endometriosis include painful or heavy periods, chronic pelvic pain, and pain during sex or with opening your bowels. Endometriosis can also cause fatigue and bloating, particularly around your period. If you think you may have endometriosis, it’s important to speak with your GP about avenues for diagnosis and discuss potential management. For women with confirmed endometriosis, certain treatments may be recommended to improve the chances of becoming pregnant.
Fibroids were picked up on a scan - which types actually reduce fertility, and when is removal worth it?
It’s common for fibroids to be detected incidentally on a scan, and most fibroids do not significantly impact fertility. Fibroids which interfere with the normal size and shape of the womb (e.g. submucosal or large intramural fibroids) are more likely to interfere with fertility, as they can impact implantation and increase the risk of miscarriage. Removal of fibroids may be recommended if you have been having difficulty conceiving, or if they are causing you troublesome symptoms (e.g. heavy periods or pain).
I’ve been told I have PCOS - what’s the best way to support my fertility and does it always mean I’ll struggle to conceive?
PCOS (polycystic ovarian syndrome) is common and can cause difficulty conceiving, as it can cause irregular cycles and unpredictable ovulation. However, many women with PCOS do become pregnant naturally, and having PCOS does not always mean you’ll struggle to conceive. The best ways to support your fertility are maintaining a healthy weight, engaging in regular exercise and keeping a healthy diet. Avoiding smoking and excess alcohol can also help fertility. When trying to conceive, it’s recommended to have sex every 2-3 days. If you do find conception is not happening for you, speak with your GP about potential ovarian stimulation therapy or specialist support.
How much does men’s fertility really matter when trying to conceive, and does it also affect the health of the pregnancy?
Men’s fertility certainly matters when trying to conceive, and in fact, around 40-50% of cases of infertility involve some problem with the sperm. For men, smoking, excessive alcohol, being overweight and using recreational drugs can all reduce sperm quality. Sperm quality can also have an impact on the health of the pregnancy, as pregnancies conceived with poor quality sperm have a higher rate of miscarriage.
Boxers vs briefs - does it actually matter for sperm?
There’s some evidence that wearing boxers is better for sperm quality than wearing briefs; however, the difference is not likely to be very significant. Sperm thrive at a slightly lower temperature than body temperature, so the theory is that for men who wear tight-fitting briefs, their sperm is not kept at an optimum temperature and therefore is of poorer quality. Factors such as smoking, excess alcohol and general health likely have a much greater impact on sperm quality than underwear choice.
Do some lubricants harm sperm - what should we use instead?
Yes, some lubricants (e.g. KY jelly, Durex Play or Astroglide) can hinder sperm motility and survival. It’s recommended to avoid the use of lubricants when trying to conceive, unless there are specific reasons to do so, e.g. vaginal dryness. While there’s no specific clinical advice on which lubricant to use when trying to conceive, it may be beneficial to use one which is specifically designed to be sperm-friendly or fertility-friendly.
My partner had flu/Covid - can that effect sperm and for how long?
Yes, illnesses such as flu or COVID can impact sperm quality, particularly if your partner had a high fever or was very unwell. Most men’s sperm quality, if affected, will fully recover once they are well again. Because sperm take around 72–90 days to fully develop, any effects may be seen for up to three months after illness. Maintaining a healthy diet, exercise, and lifestyle can help with recovery from illness and also support sperm health.
We’re timing sex around ovulation - how often is “best” without making it feel like a chore?
When trying to conceive, it’s recommended to have sex every 2-3 days, keeping sex relaxed and enjoyable. Focussing on daily sex around ovulation can be effective, however, this isn’t necessary and may increase stress or pressure, or make sex feel clinical.
Every journey is unique, and while challenges can arise, many people go on to conceive successfully with the right support.
References
· NICE Clinical Guideline 156: Fertility problems: assessment and treatment. National Institute for Health and Care Excellence (2013, updated 2017). https://www.nice.org.uk/guidance/cg156
· https://www.nice.org.uk/guidance/cg156
· NHS (2023). Infertility. https://www.nhs.uk/conditions/infertility/
· NHS (2023). Vitamins, supplements and nutrition in pregnancy. https://www.nhs.uk/pregnancy/keeping-well/vitamins-supplements-and-nutrition/
· Mínguez-Alarcón L, et al. “Type of underwear worn and markers of testicular function among men attending a fertility center.” Human Reproduction. 2018;33(9):1749–1756 https://doi.org/10.1093/humrep/dey259
· RCOG Patient Information: Endometriosis and fertility. Royal College of Obstetricians and Gynaecologists. https://www.rcog.org.uk/for-the-public/browse-all-patient-information-leaflets/endometriosis
· HFEA (Human Fertilisation and Embryology Authority): Advice on fertility and treatment options. https://www.hfea.gov.uk
· Birmingham Women’s and Children’s NHS Foundation Trust: Improving your chances of conception (local patient leaflet with advice on lubricants and lifestyle). https://bwc.nhs.uk/how-you-can-improve-your-own-chances
