Iron deficiency in pregnancy: why it's so common, and how the midwife pathway works

Iron deficiency is one of the most common complications of pregnancy in New Zealand - and one of the most under-discussed. Growing a baby, a placenta and a significantly expanded blood volume roughly triples your daily iron requirement, and many women start pregnancy with reserves that were already low. The result: by the second or third trimester, tiredness that goes well beyond 'normal pregnancy tired'.

Why it matters for you and baby

Iron deficiency in pregnancy is associated with fatigue, reduced ability to cope with blood loss at birth, and, when it progresses to anaemia, effects on baby's growth and iron stores. It's also very treatable - which is exactly why your midwife or LMC checks your bloods at booking and again around 28 weeks.

Tablets first - and when they're not enough

Oral iron remains the first-line treatment in pregnancy, and for many women it works well. But tablets have two well-known limitations: they commonly cause constipation, nausea and stomach upset (already familiar territory in pregnancy), and they rebuild iron stores slowly. When a woman is well into her pregnancy with low ferritin, or simply can't tolerate tablets, there may not be enough time for oral iron to do its job before birth.

That's where an intravenous iron infusion comes in. Current New Zealand guidance supports ferric carboxymaltose (Ferinject) in the second and third trimesters when oral iron has failed or fast restoration is needed. It isn't used in the first trimester.

How the midwife pathway works with us

• Your midwife or LMC identifies low ferritin or haemoglobin on your routine bloods.
• You book an iron assessment with us and upload those blood results directly in the booking form.
• Our screening asks specifically about your pregnancy - gestation, due date, and your midwife's details - and, with your consent, we can liaise with your midwife directly.
• The prescriber reviews everything before any infusion is approved. Screening in pregnancy is deliberately thorough - that's a feature, not a hurdle.
• The infusion itself happens in your own home, with monitoring before, during and for 30 minutes afterwards.

Questions worth asking

Whoever provides your infusion, you should feel free to ask: Who is prescribing this, and have they seen my bloods? What are the side effects, including the delayed ones? What happens if I have a reaction? Any provider doing this properly will welcome those questions - informed consent in pregnancy matters twice over.