Iron deficiency anaemia and postpartum haemorrhage
Postpartum haemorrhage (PPH) is when you lose more blood than normal at, or after giving birth. This is defined as a loss of more than 500ml at a vaginal birth and more than 1000ml associated with a caesarean birth.
If this occurs within the first 24 hours after the birth it’s called a primary PPH. Otherwise, if it occurs after this 24-hour time frame but within 6 weeks after birth, it's called a secondary PPH.
Postpartum haemorrhage happens after 5-15 out of every 100 births in Australia. For many mothers who have a PPH, they don’t have any known risk factors. However, the risk of a PPH is more likely if a mother has birthed more than 3 times previously, has had a large baby or babies, or multiple babies.
Other risk factors include having a low level of iron in your blood (anaemia), having uterine fibroids, a BMI over 35, high blood pressure, diabetes, a bleeding disorder, an issue with how the placenta is attached to the uterus (eg. placenta previa), or a previous PPH.
Mothers are also at a higher risk of PPH if they have a very long or a very fast labour, they have their labour induced, they have an instrumental birth (forceps, vacuum), have a caesarean birth, or have issues with the placenta coming away from uterine wall.
IRON DEFICIENCY ANAEMIA
If you’re pregnant and you’re iron deficient and/or you have iron deficiency anaemia (IDA), your risk of experiencing a postpartum haemorrhage (PPH) increases.
Having IDA involves having low haemoglobin levels. Haemoglobin is the oxygen-carrying protein found in red blood cells.
Being iron deficient, or having IDA is linked to postpartum haemorrhage in terms of uterine atony. And the more severe the anaemia, the more likely the greater blood loss (postpartum haemorrhage) and the adverse outcomes of such.
WHAT IS UTERINE ATONY?
Put simply, it’s the lack of uterine (muscle) tone and the failure of the uterus to contract sufficiently after birth (also known as a ‘boggy uterus’). The uterine muscles are ‘weak’ and don’t contract enough to clamp down the placental blood vessels after the placenta has been sheared off the uterine wall. Remember, the site of the placenta is highly vascular!
Put more ‘scientifically’, the anaemia (ie. the lack of haemoglobin, the iron-carrying compound in the blood) impairs how oxygen is transported and circulated within the uterus muscle (myometrium). This causes dysfunction in tissue enzymes and cells. This can lead to life-threatening blood loss after birth.
WHAT YOU CAN DO
Approximately 40% of women enter pregnancy iron deficient! So ideally, preconception is the time when both haemoglobin levels and iron stores should be tested.
Heading into a pregnancy with low iron stores is far from ideal. Low maternal iron intake at the time of conception has been associated with a greater risk of autism in the baby, and there are various established links between fetal or early postnatal iron status and long-term neurocognitive and mental health issues.
Entering pregnancy with low iron stores will soon see it reduce very quickly. Especially in the 2nd trimester when a mother’s blood volume expands by 50% and the baby is building their blood and stocking up iron stores in their liver for after the birth.
I like my mums to have a haemoglobin level of 130-135g/L and a ferritin (stored iron) of at least 60-70ug/L, either before pregnancy or towards the end of 1st trimester. Testing these levels late in the 1st trimester is a great indicator of how likely iron adequacy will be late in pregnancy (ie. by late 2nd trimester-early in 3rd trimester). And if they are not great when tested towards the end of 1st trimester, then it allows enough time to work on them. Testing this early just makes sense
It’s also important to consider the other iron markers; transferrin and transferrin saturation. Transferrin tells us how ‘hungry’ the body is for iron, and the saturation tells us about the transport and utilisation of iron around the body. This job involves co-factors such as copper and retinol/Vitamin A.
As the pregnancy progresses, there are some changes to these iron markers. Some of these changes are to be expected and therefore it’s important to interpret blood test results correctly within this context.
I have the mums I work with get their levels tested once in each trimester. This helps us stay proactive and ahead of any potential issues.
Iron deficiency anaemia (IDA) [pregnant or not] is when:
Haemogloblin is ≤110g/L, and ferritin is <15 or <13.
Once at these levels, you’d benefit from an iron infusion*.
Iron deficiency anaemia (IDA) in pregnancy is when:
Haemogloblin is ≤105g/L, and ferritin is <13, in the 2nd trimester or,
Haemogloblin is ≤100g/L, and ferritin is <13, in the 3rd trimester
*An iron infusion is recommended here because IDA can pose further risks to the baby such as affecting their iron stores, their birth weight and potentially premature birth. Not to forget, increasing the risk of postpartum haemorrhage in the mother. I consider an iron infusion a last resort and prefer to get my mums never needing one in pregnancy. This is very possible, especially if testing is done sooner in pregnancy and raising the ideal ferritin to at least 60-70ug/L at preconception or early trimester one.
IRON SUPPLEMENTS
If it’s been established that you could benefit from an iron supplement, hopefully this has been discovered sooner than later in pregnancy. There are some preferred types of iron supplements; they are not all created equally!
An iron supplement in the form of iron biglycinate is preferred. This has greater bioavailability and therefore absorption. It’s also far less likely to cause digestive upset and/or constipation like other iron supplements (eg. Ferrograd). It’s also important to consider dietary intake of the co-factors needed for iron absorption and utilisation with the body eg. vitamin A (retinol) and copper.
Another common recommendation is Maltofer (liquid or capsules). Again, I don’t recommend this because there are much better formulas available. Considering consult with a Naturopath or a Clinical Nutritionist for their recommendations.
CONSIDERATIONS
Iron deficiency or having IDA is just one risk factor for postpartum haemorrhage. Yet it’s one we can test for (remember the earlier the better) and act upon using dietary guidance and/or great quality, highly absorbable iron supplements if need be.
A mother who experiences a PPH will enter her postpartum depleted. It’s also very important to work on rebuilding her iron (and B12) levels throughout these early weeks and months. For being iron deficient or having IDA increases the risk of experiencing postpartum depression and/or anxiety.