Extreme Tiredness in the First Trimester

Why you are this tired

The tiredness of early pregnancy surprises people because it does not behave like ordinary tiredness. It is not proportional to what you have actually done, and sleeping longer does not reliably fix it. People routinely describe being wiped out by a normal day.

The HSE gives the clearest breakdown of what is driving it:

• Hormonal changes — specifically rising levels of progesterone.
• Physical changes — "pregnancy uses a lot of energy as your body changes".
• Circulatory changes — your body produces more blood, blood pressure may drop, and blood sugar may be lower.
• Emotional changes — anxiety is common in the early stages, and anxiety is exhausting in its own right.

The NHS adds that hormonal changes at this time "can make you feel tired, nauseous and emotional", and that tiredness is especially common in the first 12 weeks. It is worth noticing that all of this is happening before there is any visible bump — which is exactly why the fatigue feels disproportionate and why other people do not see it.

When it lifts

This is usually the thing people most want to know, and the sources agree closely:

• The HSE: "Energy levels usually improve by the second trimester (weeks 14 to 26)."
• Pregnancy, Birth and Baby: "You'll probably have more energy after 14 weeks."

Tiredness commonly returns in the third trimester, but for a different reason — carrying more weight and sleeping less well, rather than the hormonal exhaustion of early pregnancy.

What is normal

• Needing to sleep far more than usual, or needing to lie down during the day.
• Being wiped out by activities that were previously unremarkable.
• Tiredness that varies day to day rather than being constant.
• Feeling tired despite sleeping a normal amount — this is not a sleep-quantity problem.

What is not just pregnancy tiredness

Fatigue is the one early pregnancy symptom that most often has a second, treatable cause sitting underneath it. Two are worth knowing about.

Iron deficiency and anaemia

Pregnancy, Birth and Baby states that tiredness "might be a symptom of anaemia due to low iron levels, which is common in pregnancy, as your body needs more iron", and puts anaemia at about 1 in every 4 pregnancies.

Anaemia is defined by haemoglobin below roughly 110 g/L (11.0 g/dL) before 20 weeks and 105 g/L (10.5 g/dL) after 20 weeks. A 2024 Cochrane review of daily oral iron in pregnancy, covering 57 trials and 48,971 women, used haemoglobin below 110 g/L at 37 weeks or more as its definition of anaemia at term, and found that daily iron probably reduces iron-deficiency anaemia at term (5.0% versus 18.4%; risk ratio 0.41, moderate-certainty evidence).

Symptoms beyond tiredness that point towards anaemia, per Pregnancy, Birth and Baby: feeling weak, dizziness, headache, shortness of breath and chest pain. The HSE independently flags dizziness alongside tiredness as a reason to make contact.

Pregnancy, Birth and Baby notes you should have a blood test when you first see a doctor or midwife about your pregnancy, and usually another at around 28 weeks. You do not have to wait for those appointments to raise it. The HSE lists tiredness accompanied by dizziness, breathlessness, chest pain or heart palpitations as a reason to contact your GP or midwife directly, rather than waiting for a routine test.

Why the blood test matters more than the rest

Anaemia is worth pursuing precisely because it is common, easily identified and treatable — unlike the hormonal fatigue underneath it, which simply has to pass. Treatment is iron tablets, or intravenous iron where tablets are not tolerated or not working fast enough.

It is also the reason to be specific when you make contact. "I am exhausted" invites reassurance that tiredness is normal in pregnancy, which is true and unhelpful. "I am exhausted, rest is not helping, and I would like my iron checked" gets you the test.

When to call a midwife or doctor

Contact your midwife or doctor if:

• You are exhausted and more rest does not help. Pregnancy, Birth and Baby names this specifically as a reason to see a doctor.
• Tiredness comes with dizziness, breathlessness, chest pain or heart palpitations — the HSE's red-flag list.
• You look unusually pale, or have headaches with the fatigue.
• You have started snoring or have pauses in your breathing during sleep — Pregnancy, Birth and Baby names this specifically.
• Your mood is low or your anxiety is high. The HSE lists this alongside the physical causes, and it is a legitimate reason to make contact.

What actually helps

There is no treatment that removes first-trimester fatigue, and it would be misleading to suggest otherwise. What the guidance actually supports:

• Get the blood test rather than pushing through. If there is a treatable cause, this is the step that finds it. Iron treatment is tablets, or intravenous iron where needed.
• Take the recommended supplements. The NHS advises 400 micrograms (0.4 mg) of folic acid daily for the first 12 weeks, and 10 micrograms of vitamin D daily from early October to late March — or year-round with limited sun exposure or darker skin. Some people need a higher 5 mg dose of folic acid on prescription. Do not take cod liver oil or any supplement containing vitamin A (retinol).
• If you are prescribed iron, keep taking it. Side effects such as constipation are common and are worth raising with your midwife or pharmacist rather than quietly stopping — the Cochrane evidence is for iron actually taken.
• Some activity helps more than none. Both the NHS and Pregnancy, Birth and Baby note that exercise in pregnancy can increase energy — a lunchtime walk or swimming rather than anything strenuous.
• Protect sleep at the edges. Avoid caffeine in the evening. Sleep on your side, particularly after 28 weeks.
• Reduce load deliberately. The HSE explicitly suggests asking family and friends for help and talking to your manager or colleagues about what changes at work could help. That is guidance, not indulgence.