Changes in the management of iron in pregnancy

The challenge of identifying pregnant women with low iron

The issue for many women, and for their care providers, is that they may be unaware of their low-iron stores and only when they become pregnant that the problem is identified. Even with standard blood screening in routine antenatal care at booking and 28 weeks (NICE, 2018) because stores can be depleted before there might be a noticeable decrease in haemoglobin concentration, unless a serum ferritin is checked, the problem may not be identified (Rukuni et al, 2015). The result of this is that a delay in identifying the iron depletion is that the negative sequalae might already be in motion: symptoms may occur even on the absence of anaemia (Science Advisory Committee on Nutrition, 2010). While identification of pregnant individuals with low-iron reserves poses challenges in and of itself, effectively treating iron deficiency is by no means simple.

Oral iron supplementation

The global iron market is dominated by products with very poor absorption and effectiveness. The obvious solution to poor absorption might be to increase the dose but increasing the dose of poorly absorbed iron often leads to gut irritation and therefore non-compliance. Gut irritation occurs when oxidised iron damages the gut cells, the side effect of iron supplementation most reported is constipation, followed by nausea. It is estimated that 80%–90% of people who take iron tablets report side effects.

Iron is a highly reactive mineral which is capable of causing cell irritation and damage, and up until recently both oral and IV formulations were known to be far from perfect due to tolerability and safety issues (Girelli, 2018). As the iron is absorbed further down the digestive tract, the upper gastrointestinal area can be severely irritated (Kaye et al, 2008). Women on oral iron supplementation can complain of gastrointestinal discomfort, nausea, dyspepsia and constipation (Pavord et al, 2019). That these symptoms may often occur in a normal healthy pregnancy means that iron often exacerbates an underlying minor problem (Girelli et al, 2020). The issue is two-fold due to side effects: either complete non-compliance due to tolerability or taking supplements in such small doses that they are totally ineffectual. It is important to state that while most of the side effects suffered by people taking iron supplements will improve once the treatment has stopped, for some there may be long-term implications and damage to their gut mucosa (Tolkien et al, 2015; Brannon and Taylor, 2017).

Poor absorption in traditional iron supplements

Most oral supplements, while inexpensive and readily available, have severe limitations (Deeba et al, 2012; Peña-Rosas at al, 2015). Bioavailability of iron varies hugely. While the compound weight of a particular tablet may appear high, the elemental iron will be a much smaller percentage of it (Santiago, 2012). Furthermore, of the elemental iron available, only a fraction of it is absorbed, as low as 10%. The reason for this is that most iron absorption occurs lower down in the duodenum and upper jejunum (Ems and Huecker, 2019). Unlike other nutrients that are absorbed directly through gut mucosa, iron requires carrier mechanisms such as the divalent metal transporter 1 (DMT-1). Other factors that can interfere with absorption are the timing of the dose, dietary factors (other compounds can interfere with absorption such as polyphenols and phytates) and other medications (Pavord et al, 2019).

For pregnant women who are not anaemic or symptomatic, there could be a real opportunity to possibly prevent them developing iron deficiency by offering supplementation in a low dose, easy tolerated formulation; this is where Active Iron is ideally positioned for health optimisation. Active Iron is scientifically formulated to increase absorption and reduce side effects.