Many GPs reluctant to give IV iron in second and third trimester, despite expert recommendations

More than half of GPs would not prescribe iron infusions for iron deficient women without anaemia in the second or third trimester of pregnancy, Healthed’s latest survey suggests, but experts say it is safe and effective, and has important benefits for both mum and foetus.

Haematologist Dr Lisa Clarke of Sydney Adventist Hospital and Australia Red Cross Lifeblood is leading the development of multidisciplinary consensus-based guidelines on managing iron deficiency in absence of anaemia in the obstetric setting.

Dr Clarke recommends a low threshold for considering intravenous iron as a therapy for iron deficiency in the second or third trimester of pregnancy, and says that concerns about anaphylaxis risk have been alleviated with new formulations.

But many GPs remain reluctant.

Healthed asked over 1,000 GPs if they would prescribe iron to a patient in the second or third trimester who was iron deficient but did not have anaemia.

More than half (56%) said they would not.

In the above scenario, Dr Clarke said she would consider oral iron first, but educate her patient that it isn’t tolerated by everyone, and if adverse side effects occur, then IV iron is the appropriate option.

She says there’s a significant under appreciation in the medical community of the impact of iron deficiency in the absence of anaemia.

“It’s remiss of us to wait until anaemia has developed, because once we wait it is more challenging to manage, because we are essentially more desperate and want the patient to absorb more from each of their dose of oral iron, which may increase side effects and reduce compliance. And it’s putting us in a position where we almost only have IV iron as an option,” Dr Clarke says.

Dr Clarke says effective management of iron deficiency is crucial, not only due to the risk of progression to anaemia, but also because of the “the risk of accepting a poor quality of life and poor functioning for half a population.”

“Every decision that we make in medicine needs to be about weighing up the risks and the benefits. We often just focus on the really rare adverse side effects of IV iron, and not really on the beneficial effects of iron, which are obviously for mum in terms of their wellbeing, but really for that developing foetus who needs iron,” she says.

While IV iron should not be given in the first trimester due to lack of safety data, a multitude of studies and meta-analyses have concluded that it is safe and effective from 13-14 weeks onward, and best practice guidelines have been revised accordingly.

Oral iron is still the first-line recommended treatment for iron deficiency, but gastrointestinal side effects are common, and very often lead to non-adherence. In these cases, IV iron is the preferred option after the first trimester.

Yet perceptions of risk have been hard to shake.

“To be perfectly honest, IV iron definitely gets a bad rap. And that comes from the historical anaphylactic or significant allergic reactions of the older preparations” Dr Clarke says.

The risk of allergic reactions or anaphylaxis from IV iron were reported with the HMWID formulation which is no longer available. Newer formulations are much safer.

Dr Clarke says that apart from in the first trimester, or perhaps in someone with multiple severe drug allergies, IV iron can be safely considered for most patients once they enter the second trimester.

Clinical Associate Professor Pradeep Jayasuriya of the University of Western Australia and WA Iron Centre concurs with Dr Clarke.

He says that evidence has changed significantly in the last 10-15 years, and anaemia is no longer considered the trigger for intervention in pregnancy.

“In 10 years there has not been one single reported serious adverse event for the foetus all over the world,” Associate Professor Jayasuriya says.

“The evidence for safety is overwhelming and the benefits for the pregnancy are substantial. There is a relative urgency for treatment as well, particularly in the third trimester.”

“Iron deficiency without anaemia is associated with adverse neurodevelopmental outcomes in the third trimester, and should be treated,” he says.

The benefits of IV iron in pregnancy include fewer adverse side effects than oral iron, improved maternal wellbeing, reduced risk of anaemia and associated morbidity and mortality, improved foetal development, and reduction of symptoms of iron deficiency such as shortness of breath.

Iron is also required for the sufficient production of dopamine and serotonin, so iron deficiency is also linked to depressed mood, Dr Clarke says.

And IV iron can be particularly beneficial in later pregnancy when time is of the essence, she adds.

For more information:
Red Cross Lifeblood has a maternity toolkit for GPs, including decision-making flowcharts for iron optimisation in pregnancy. These have recently been updated with a focus on iron deficiency with or without anaemia.
The National Blood Authority also has developed the Patient Blood Management Guidelines: Module 5 – Obstetrics and Maternity which can be helpful.

A total of 1,126 GPs responded to Healthed’s survey, which opened on 21 February 2023. GPs were allowed to skip questions, which is why each question has a different number of GP participants. Survey demographics are summarised in the charts below.

Credits

Survey conception and design– Dr Ramesh Manocha

Survey analysis and visualisation– Yasmin Clarke

Editing and reporting– Lynnette Hoffman