Azathioprine doesn't affect fertility in men or women. BSR guidelines advise that it can be taken in pregnancy at doses no higher than 2 mg/kg.
Tiny amounts of it do appear in breast milk but it has not been shown to cause any harm so it can be taken by breastfeeding mothers.
If you're planning a family or become pregnant while taking azathioprine, you should talk to your doctor as soon as possible.
Ciclosporin is used widely in people who've had transplants as well as for arthritis, and many women who have used the drug have had successful pregnancies.
BSR guidelines advise that it can be taken in pregnancy. Very small amounts of the drug get into breast milk but it has not been shown to harm babies, and BSR guidelines advise cautious use in breastfeeding.
If you're planning a family or become pregnant while taking ciclosporin, you should talk to your doctor as soon as possible.
Cyclophosphamide can reduce fertility in both men and women, so you may be advised to 'bank' sperm or have ovarian tissue stored before you start treatment with the drug.
If possible, cyclophosphamide should be stopped at least three months before trying for a baby, and it should be avoided during pregnancy as it's likely to be harmful.
Bottle-feeding is recommended if you need to take this drug after the baby is born.
Hydroxychloroquine is often taken to prevent malaria as well as to treat arthritis and lupus. It doesn't increase the risk of birth problems at doses used to treat arthritis and lupus.
In fact, research has shown that women with lupus who stop this drug before pregnancy have worse pregnancy outcomes than those who carry it on.
BSR guidelines advise that it can be taken during pregnancy and breastfeeding.
There is concern that leflunomide may cause birth defects and so it should be avoided before and during pregnancy. Reliable contraception should be used when taking this drug.
Leflunomide stays in the body for a long time. If you're taking leflunomide and want to start a family, talk to your doctor. BSR guidelines advise that women on leflunomide who want to get pregnant should stop it, have a special wash-out treatment to remove it from the body more quickly and switch to other drugs that can be used in pregnancy before trying for a baby.
If you become pregnant while taking leflunomide, stop the drug and speak to your doctor as soon as possible about having the wash-out treatment.
As long as you do both of these things it is very unlikely that leflunomide will have caused harm to your baby. The guidelines also advise that leflunomide can be taken by men without the need for the wash-out treatment before trying to father a child.
Leflunomide shouldn't be used while breastfeeding.
You shouldn't take mycophenolate when you're pregnant, and you shouldn't become pregnant for at least six weeks after you stop taking the drug. Mycophenolate must not be taken while you're breastfeeding.
If you're planning a family or if you become pregnant while taking mycophenolate, you should discuss this with your doctor as soon as possible.
Methotrexate must not be taken while you're pregnant or breastfeeding, and it should be stopped three months before you try to become pregnant.
Previously, there was concern that methotrexate may affect sperm and thus any fertilised egg but this has not been shown to be a problem in research studies. BSR guidelines state that men do not need to stop methotrexate before trying for a baby.
If you're planning a family or become pregnant while on methotrexate, you should speak to your doctor as soon as possible.
Women can continue taking sulfasalazine when trying for a baby and during pregnancy with 5 mg folic acid tablets per day (these will need to be prescribed by a doctor). It's often recommended women continue taking sulfasalazine through pregnancy to prevent a flare-up of their disease.
Although sulfasalazine may cause a fall in sperm count, leading to a temporary decrease in male fertility, that is reversed if treatment is stopped and this has not been shown to be a problem in research studies.
BSR guidelines advise that men do not need to stop sulfasalazine before trying for a baby unless they have already been trying unsuccessfully for one year.