When pregnancy fatigue is more than just tiredness

Pregnancy can be physically demanding in ways that are both obvious and less visible. Hormonal shifts, disrupted sleep, a growing baby and the increasing demands placed on the body can all leave expectant mothers feeling tired.

But there is a point at which fatigue deserves a closer look, particularly when it becomes persistent, excessive, or is accompanied by symptoms such as weakness, dizziness, shortness of breath or heart palpitations.

One possible cause is iron deficiency anaemia (IDA), a common and treatable condition that can affect pregnant women.

The World Health Organisation defines anaemia in pregnancy as a haemoglobin concentration below 11 g/dL, although interpretation may also depend on the stage of pregnancy and other clinical factors.

Iron deficiency is the most common nutritional cause, but it is not the only one. Folate or vitamin B12 deficiency, blood loss, inflammation and inherited blood disorders can also contribute, which is why symptoms alone are not enough to make a diagnosis.

The overlap between ordinary pregnancy symptoms and anaemia can make the latter easy to miss. Persistent exhaustion, especially when accompanied by breathlessness, weakness, dizziness or palpitations, may indicate that haemoglobin levels or iron stores are falling below what the body needs.

Importantly, iron deficiency can develop before anaemia itself becomes apparent. A woman may already have depleted iron stores even while her haemoglobin remains above the diagnostic threshold, which means early detection can help prevent the condition from progressing.

This is where routine antenatal care becomes especially important. Blood tests can identify anaemia and, where necessary, help determine whether iron deficiency is the underlying cause or whether another condition needs to be investigated.

Pregnancy significantly increases the body’s demand for iron because more is needed to support the expansion of maternal blood volume, development of the placenta and the growth of the baby. For women who begin pregnancy with relatively low iron stores, meeting that increased demand can become difficult, particularly as pregnancy progresses.

The issue is relevant in Malaysia, where a systematic review of studies involving pregnant women found that anaemia prevalence ranged from 19.3% to 57.4%, while iron deficiency ranged from 31.6% to 34.6%.

The review also identified several factors associated with anaemia and iron deficiency, including late antenatal booking and failure to take prescribed iron supplements consistently.

For the mother, IDA can affect energy levels, general wellbeing and physical functioning. As the condition becomes more severe, it may also reduce the body’s ability to cope with blood loss during childbirth, as a woman who is already anaemic has less physiological reserve.

For the baby, maternal anaemia and iron deficiency have been associated with outcomes such as preterm birth, low birth weight and reduced neonatal iron stores. Adequate iron is also important for foetal development, including the development of the brain.

That does not mean every woman with mild anaemia will experience complications; many go on to have otherwise uncomplicated pregnancies. The concern is that untreated iron deficiency may leave both iron stores and haemoglobin levels depleted by the time of delivery, with effects that can continue into the postpartum period.

Early testing can make a difference

Malaysia’s antenatal care system includes routine haemoglobin assessment, providing an opportunity to detect anaemia before symptoms become severe. If low haemoglobin is identified, additional testing may be needed to confirm whether iron deficiency is responsible or whether another cause should be considered.

When advised by a healthcare professional, iron and folic acid supplementation can help restore or maintain adequate levels. A balanced diet containing iron-rich foods also plays a supporting role, although diet alone may not always be sufficient once deficiency has developed.

For pregnant women, the practical message is relatively straightforward: keep up with antenatal appointments, complete recommended blood tests, and discuss symptoms that feel persistent or disproportionate rather than assuming they are simply part of pregnancy.

Prescribed supplements should also be taken as directed, particularly since poor adherence can make it harder to correct declining iron stores.

This article was written by Dr Farzana Rizwan, Dr Malar Kandasamy and Dr Ganesh Ramachandran from Taylor’s University’s School of Medicine, Faculty of Health and Medical Sciences.

Subscribe to our newsletter and get news delivered to your mailbox.