“My obstetrician said I should be seen by a haematologist. Is there something wrong with my baby?”
“I have been taking iron for months and nothing has changed. Is it going to harm my baby?”
“They found I have a problem with thrombophilia. I do not understand what it is. They said it has been causing my spontaneous abortions. What should I do? I want my pregnancy to go well.”
“My platelets dropped at my last CBC check. I am 34 weeks pregnant. I was told I might not be able to have an epidural.”
Pregnancy changes almost everything in your body, and your blood is no exception. Your blood volume increases, your iron stores are shared with a growing baby, your clotting system shifts, and your platelet count can change. Most of these changes are normal. But when a lab result comes back flagged, or your obstetrician says the words “you need to see a haematologist,” the worry can take over fast.
I see pregnant women in my clinic regularly. Some are sent early, others late in pregnancy, and some only after delivery when something did not go as expected. The questions are remarkably similar across all of them.
Here are the ten I hear most often, and the answers I give.
1 – “Why was I referred to a haematologist?”
Usually because something showed up on routine blood work that your obstetrician wants a second pair of eyes on. That could be low haemoglobin, low platelets, an abnormal blood smear, a known condition like thalassemia trait, or a positive thrombophilia test.
Being referred does not mean something is seriously wrong. It means your doctor is being thorough. In most cases, we clarify the finding, set up a monitoring plan, and work alongside your obstetric team to make sure delivery goes smoothly.
2 – “I have anaemia. Is it dangerous for my baby?”
This is probably the most common reason pregnant women end up in a haematology consultation.
Mild anaemia in pregnancy is extremely common and, in most cases, it is iron deficiency. Your body needs significantly more iron during pregnancy, for expanded blood volume, for the placenta, and for the baby. When stores run low, haemoglobin drops.
Mild iron deficiency anaemia is manageable and not immediately dangerous to you or the baby. But when anaemia becomes moderate or severe, or when it does not respond to iron supplements, it needs attention. Untreated significant anaemia can affect how you feel day-to-day (fatigue, dizziness, breathlessness), and in more severe cases it can affect fetal growth and increase the risk of complications around delivery.
The key is not to panic, but also not to ignore it. If your haemoglobin is dropping despite taking iron, tell your doctor. There may be a reason the iron is not working, and that reason matters.
3 – “I have been taking iron tablets for weeks and my levels have not improved. What is going on?”
This is one of the questions I find myself answering the most, pregnant or not.
There are many reasons oral iron may not work as expected. The most common ones are timing and absorption. Iron is best absorbed on an empty stomach, away from tea, coffee, dairy, and calcium supplements. If you are taking it with breakfast or alongside your prenatal vitamin that contains calcium, the absorption drops significantly. I have written more about this in my article on Taking Supplements? Here’s How to Do It Right.
Other reasons include ongoing blood loss (even small amounts), gastrointestinal conditions that impair absorption, or simply that the dose or formulation is not right for you. In some cases, the anaemia is not purely iron deficiency. It may be mixed with B12 or folate deficiency, or there may be an underlying condition that needs investigating.
If your iron levels remain stubbornly low despite consistent supplementation, intravenous iron is a safe and effective option during the second and third trimesters. It bypasses the gut entirely and replenishes stores more reliably.
4 – “My platelets are low. Should I be scared?”
No, but you should be informed.
Low platelets in pregnancy are common, and the most frequent cause is gestational thrombocytopenia, a mild, harmless drop that happens in late pregnancy and resolves after delivery. It does not cause bleeding problems, does not affect the baby, and does not need treatment.
However, if platelets drop below roughly 70 ×109/L (70,000/µL), or if the drop happens early in pregnancy, or if you have bleeding symptoms, other causes need to be considered, including immune thrombocytopenia (ITP) and pregnancy-specific conditions like preeclampsia or HELLP syndrome. That number is not a hard rule. The decision to investigate further depends on the trend, the cause, your bleeding history, and other clotting parameters.
The trend matters more than a single number. I wrote a detailed guide on this topic: Low Platelets While Pregnant: A Simple Guide to GT vs ITP.
The short version: most low platelet counts in pregnancy are mild and manageable. What matters is monitoring and planning ahead, especially for delivery and anaesthesia decisions.
5 – “I have thalassemia trait. Will my baby be affected?”
Thalassemia trait (also called thalassemia minor) means you carry a mild change in a haemoglobin gene (alpha or beta). On its own, it usually causes a mild microcytic anaemia that does not require treatment, though it is often mistaken for iron deficiency.
The concern during pregnancy is not so much about you, but about the baby. If both parents carry a thalassemia trait, there is a chance the baby could inherit a more severe form, thalassemia major or intermedia. This is why partner testing is important, ideally before or early in pregnancy.
If your partner does not carry a trait, your baby may inherit the trait but will not have severe disease. If both of you carry a trait, genetic counselling is recommended so you can understand the possibilities and make informed decisions.
One practical point: if you have thalassemia trait, your haemoglobin may sit slightly lower than average throughout pregnancy, and that is expected. Not every low hemoglobin in a woman with thalassemia trait needs iron. Over-supplementing with iron when stores are already adequate can do more harm than good. Check your ferritin before assuming you need more iron.
6 – “I was told I have a thrombophilia. Do I need blood thinners during pregnancy?”
Thrombophilia is a term that covers many different conditions, some inherited (like Factor V Leiden, Prothrombin G20210A mutation), some acquired (like antiphospholipid syndrome), and some that are more controversial in terms of clinical significance (like MTHFR variants).
An important clarification: not every thrombophilia automatically “causes” miscarriages. The strongest and most treatable link between thrombophilia and pregnancy loss is antiphospholipid syndrome (APS), where specific treatment can significantly improve outcomes. For most inherited thrombophilias, the relationship with recurrent miscarriage is weaker and more debated. If you have been told that a thrombophilia caused your pregnancy losses, it is worth asking exactly which condition was found and what the evidence says about it specifically.
The answer to whether you need blood thinners depends entirely on which thrombophilia you have, your personal history, and your obstetric history.
If you have a high-risk thrombophilia, such as antiphospholipid syndrome with a history of pregnancy complications, or a strong personal history of blood clots, prophylactic anticoagulation during pregnancy is usually recommended.
If you carry a low-risk inherited thrombophilia and have no personal or family history of clots or pregnancy loss, you may not need treatment at all, just monitoring and awareness.
The MTHFR mutation is a separate conversation, and one that generates a great deal of anxiety. I have addressed it in depth here: MTHFR Mutations and Pregnancy Loss. The short answer is that most MTHFR variants alone do not require blood thinners.
Every case is individual. If you have been told you have a thrombophilia, the most useful thing you can do is bring the specific test results to your haematologist and discuss what they mean for your particular pregnancy.
7 – “I need a blood transfusion during pregnancy. Is it safe?”
Yes, blood transfusion during pregnancy is safe when it is indicated.
The most common reason for transfusion in pregnancy is severe anaemia that is not responding to other treatments, or acute blood loss around delivery. Red blood cell transfusions are matched to your blood type and screened carefully, and they can be life-saving when haemoglobin drops to critically low levels.
If you have a condition that requires regular transfusions, such as thalassemia major, pregnancy is managed by a multidisciplinary team that plans transfusion schedules around fetal development and delivery timing.
One thing I always tell my patients: do not wait until you feel terrible to agree to a transfusion if your doctors are recommending one. Severe anaemia near delivery increases risks for both you and the baby. A well-timed transfusion is a tool, not a failure.
8 – “Can I breastfeed while taking blood thinners?”
This is a question that comes up often, and the answer for the most commonly used blood thinners in pregnancy is reassuring.
Low molecular weight heparin (LMWH), such as enoxaparin, is the standard anticoagulant used during pregnancy. It does not cross into breast milk in clinically significant amounts. You can breastfeed while using it.
Warfarin is also considered compatible with breastfeeding. The amount that passes into breast milk is minimal and is not expected to affect the baby.
Direct oral anticoagulants (DOACs) are a different story. Data on their safety during breastfeeding is limited, and they are generally not the first choice postpartum if you plan to breastfeed. If you are on a DOAC for another reason, discuss this with your haematologist before delivery so a plan can be made.
The bottom line: if you need anticoagulation postpartum, breastfeeding is almost always possible. Just make sure your team knows your plan so they choose the right medication.
9 – “I bruise easily and my gums bleed. Is that normal in pregnancy?”
It can be, but it should not be dismissed without checking.
Pregnancy increases blood flow to the gums, which can make them more sensitive and prone to bleeding, especially during brushing. Mild bruising can also happen more easily due to changes in blood vessels and skin.
However, easy bruising and mucosal bleeding can also be signs of low platelets, von Willebrand disease, or other bleeding disorders. If you have always bruised easily, long before pregnancy, it is worth mentioning, because some bleeding conditions are only diagnosed when pregnancy puts extra demands on the clotting system.
I wrote about this in more detail in Doctor, I Have Bruises… Should I Be Worried? and Von Willebrand Factor: The Hidden Bleeding Risk Every Woman Should Know.
If the bruising is new, widespread, or comes with other symptoms like nosebleeds that are hard to stop, petechiae (tiny red-purple dots on the skin), or heavy bleeding, do not wait for your next appointment. Get checked.
10 – “When is it just pregnancy changes, and when should I actually worry?”
This is the question underneath all the other questions, and it is the most important one.
Pregnancy is a state of constant physiological change. Your haemoglobin will be lower than before pregnancy. Your white blood cell count may be mildly elevated. Your platelets may dip slightly in the third trimester. Your clotting factors shift. All of this can be normal.
Here is what should prompt you to seek assessment:
- Haemoglobin that keeps dropping despite treatment, or drops rapidly
- Platelets below ~70 ×109/L (70,000/µL) or falling fast
- New or worsening bleeding: gums, nose, skin, vaginal
- Severe fatigue that goes beyond the usual tiredness of pregnancy
- Symptoms like severe headache, vision changes, right upper abdominal pain, or very high blood pressure, as these can signal pregnancy complications that affect the blood and need urgent evaluation
- Any new lump, node, or mass that was not there before
- Fevers without a clear source
When in doubt, it is always safer to be checked and reassured than to stay home and wonder.
What I want you to remember
Pregnancy is a time when your body works harder than ever, and your blood is at the centre of that effort. Most haematology findings in pregnancy are manageable, especially when they are caught early and followed properly.
If you have been referred to a haematologist, it does not mean something is terribly wrong. It means your team is being careful with you, and that is a good thing.
Ask questions. Bring your lab results. Know your trend. And if something changes, new symptoms, new bleeding, a result that does not make sense, speak up. You know your body better than any lab report does.
Disclaimer
This article is for general education and does not replace medical advice, diagnosis, or treatment from your own clinician. Management decisions in pregnancy depend on your full medical history, gestational age, lab results, and local hospital protocols. If you have symptoms or concerns, contact your obstetric team or seek medical assessment.
References:
- Pavord S, Daru J, Prasannan N, et al. UK guidelines on the management of iron deficiency in pregnancy. Br J Haematol. 2020;188(6):819–830.
- ACOG Practice Bulletin No. 233: Anemia in Pregnancy. Obstet Gynecol. 2021;138(2):e26–e50.
- Bates SM, Rajasekhar A, Engel H, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy. Blood Adv. 2018;2(22):3317–3359.
- ACOG Practice Bulletin No. 207: Thrombocytopenia in Pregnancy. Obstet Gynecol. 2019;133(3):e181–e193.
- Fogerty AE. ITP in pregnancy: diagnostics and therapeutics in 2024. Hematology Am Soc Hematol Educ Program. 2024;2024(1):685–691.
- Taher AT, Musallam KM, Cappellini MD. β-Thalassemias. N Engl J Med. 2021;384(8):727–743.
- Bauer ME, et al. SOAP Interdisciplinary Consensus Statement on Neuraxial Procedures in Obstetric Patients With Thrombocytopenia. Anesth Analg. 2021;132(6):1531–1544.
- Royal College of Obstetricians and Gynaecologists. Blood Transfusions in Obstetrics. Green-top Guideline No. 47. RCOG. 2015.