This article is an important part of an ongoing debate about immune therapy. See my previous article on this (“Enough! Stop the arguments and get on with the science of natural killer cell testing”). It is definitely clear and accepted by most specialists that prednisolone does not improve outcomes for everyone. One reason could be that that while some benefit, some (as described in this article) are harmed (or their chances are decreased). Hence the need for highly specialised immune testing to try to target this therapy to those who are most likely to benefit. Tests such as NK cell testing are technically far more difficult than is often realised, and considerable effort needs too be done by the lab to produce a reliable result with a meaningful reference range. Very few labs in the world are currently able to offer that.

– Dr Gavin Sacks

Researchers at the University of Adelaide are urging doctors and patients to refrain from using a specific steroid treatment to treat infertility in women unless clinically indicated, because of its links to miscarriage, preterm birth and birth defects.

Writing in the journal Human Reproduction, researchers from the University’s Robinson Research Institute, led by Professor Sarah Robertson, say widespread use of the drug is not warranted, given there is a high degree of suspicion that corticosteroid drugs – such as prednisolone – can interfere with embryo implantation, and may have harmful effects on pregnancy and the child.

Corticosteroids are increasingly used to treat infertility in women with repeated IVF failure and . Many women receive the drug in the belief that reducing  called “natural killer” cells will facilitate a pregnancy. However, this belief is mistaken, as despite their alarming name these cells are actually required for healthy pregnancy.

Professor Robertson says there is a great deal of medical and consumer misunderstanding about the role of the immune system in fertility and healthy pregnancy.

“Steroid drugs such as prednisolone act as immune suppressants, preventing the body’s immune system from responding to pregnancy. But by suppressing the natural immune response, these drugs may lead to further complications,” Professor Robertson says.

“The immune system plays a critical role in reproduction and fertility. Natural killer cells and other immune cells help to build a robust placenta to support healthy fetal growth. But if we suppress or bypass the body’s natural biology, there can be dire consequences that don’t appear until later,” she says.

“For example, suppression of the  through inappropriate use of these drugs is linked to impaired placental development, which in turn elevates the risk of miscarriage, preterm birth and birth defects.”

Research shows that women taking corticosteroids over the first trimester of pregnancy have a 64% increase in miscarriage; the risk of  is more than doubled; and their children have an elevated risk of , including a 3-4 times greater risk of cleft palate.

“Our main message to clinicians and to women hoping to achieve pregnancy is that they should be focused on achieving good-quality pregnancy and the life-time health of the child, not just getting pregnant,” Professor Robertson says.

“Corticosteroids such as prednisolone may impair healthy , which may lead to poorer long-term outcomes for the baby.

“We believe IVF doctors should not be offering this treatment to most patients, and should discuss concerns with  who request it.

“The exception would be in specific cases where the patient has a diagnosed autoimmune condition, but those cases are rare,” she says.

Explore further: Study finds variation of the interval between first and second pregnancy

More information: Sarah A. Robertson et al. Corticosteroid therapy in assisted reproduction – immune suppression is a faulty premise, Human Reproduction (2016). DOI: 10.1093/humrep/dew186