Pertuzumab, fertility, menopause and sexual health

Pertuzumab itself is not thought to have a major direct effect on the ovaries or on future fertility. The bigger effect on fertility usually comes from the chemotherapy given alongside it, which can stop periods, bring on menopause earlier than expected, and reduce the number of eggs, especially in women closer to their forties. Pregnancy is a different matter. Pertuzumab and trastuzumab can seriously harm an unborn baby, including by reducing the fluid around the baby and affecting its development, so pregnancy must be avoided during treatment and for several months after the last dose. Effective contraception is essential, and because many breast cancers are sensitive to hormones, non-hormonal methods such as a copper coil or condoms are usually advised. Breastfeeding is also avoided during treatment and for a period afterwards. If you may want children in the future, the best time to talk about fertility preservation, such as freezing eggs or embryos, is before chemotherapy starts, because options narrow once treatment begins. Some women are also offered a monthly injection during chemotherapy that rests the ovaries and may help protect them. Sexual health changes are common during treatment. Tiredness, low desire, vaginal dryness, body image worries and stress can all affect intimacy. These are normal, often improve after chemotherapy, and practical help such as non-hormonal moisturisers and open conversation can make a real difference.

Chemotherapy has the bigger effect

Loss of periods and earlier menopause mostly relate to the chemotherapy given alongside.

Pregnancy must be avoided

HER2 antibodies can harm an unborn baby, so reliable contraception is needed.

Plan fertility early

Discuss egg or embryo freezing before chemotherapy starts.

Fertility after breast cancer treatment is hard to predict, and some questions have no firm answers yet.

Periods do not equal fertility

Periods can return while fertility is reduced, and missing periods do not mean that pregnancy cannot happen.

Preservation is not certain

Frozen eggs or embryos improve the chances of a later pregnancy but cannot promise one.

Emotions are part of this

Worry about future children, a changed body or a strained relationship can weigh as heavily as the physical effects. These feelings are common and deserve the same attention, so mention them to your nurse or doctor, who can arrange counselling or other support.

Timing needs balancing

Fertility steps must fit around the need to start cancer treatment without long delays.

What this page cannot tell you

It cannot predict your own fertility. A fertility specialist can assess egg reserve and explain your options.

Sex and closeness are often hard to talk about, especially in families where these topics are private, but they matter to quality of life.

Is sex safe during treatment?

For most people, yes, with contraception. During chemotherapy, condoms may be advised for a few days after each dose, and extra care is needed if blood counts are low.

Body changes

Surgery scars, hair loss and weight changes can affect confidence. Closeness does not have to mean sex, and many couples find new ways to stay connected.

Getting support

Your nurse or doctor has heard these questions before. Asking is a normal part of care.