The signs of leukemia in pregnancy include anemia that does not improve with iron, repeated or unusual infections, unexplained bruising or bleeding, persistent fevers, night sweats, and weight loss when you would expect to gain. Many of these overlap with normal pregnancy, which is why a complete blood count (CBC) showing abnormal white cells, very low platelets, or blasts is usually what raises the alarm. Leukemia in pregnancy is rare, but when it occurs, prompt diagnosis and a coordinated team of hematologists, obstetricians, and neonatologists can protect both mother and baby.
What Is Leukemia?
Leukemia is a cancer of the blood-forming cells in the bone marrow. Abnormal white blood cells multiply and crowd out the healthy cells that carry oxygen, fight infection, and help blood clot.
Leukemias are grouped by speed (acute or chronic) and by the type of blood cell involved (myeloid or lymphoid). In pregnancy, the acute leukemias, especially acute myeloid leukemia (AML), are the most common, followed by acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML).
Causes and risk factors
Pregnancy does not cause leukemia. The known risk factors are the same as in anyone: certain inherited conditions, prior chemotherapy or radiation, some chemical exposures, and pre-existing hematological conditions such as myelodysplastic syndrome. Leukemia in pregnancy mostly reflects the fact that some leukemias occur in young adults, the same age group who become pregnant.
Recognizing the Signs of Leukemia in Pregnancy
The difficulty is that pregnancy itself causes fatigue, breathlessness, pallor, and mild blood count changes. The table below shows how normal pregnancy findings differ from warning signs.
| Finding | Usually normal in pregnancy | Warning sign that needs review |
|---|---|---|
| Hemoglobin | Mild drop from blood volume expansion, improving with iron | Marked or worsening anemia despite iron, especially with other low counts |
| White cell count | Mildly raised, mostly neutrophils | Very high or very low count, or blasts on the blood film |
| Platelets | Mild drop late in pregnancy (gestational thrombocytopenia) | Severe drop, or drop early in pregnancy or with other abnormal counts |
| Tiredness | Common, especially first and third trimesters | Exhaustion out of proportion, with fevers or weight loss |
| Bruising and bleeding | Mild gum bleeding is common | Petechiae, large unexplained bruises, heavy nosebleeds |
Warning signs of leukemia worth reporting include:
- Persistent anemia that does not respond to iron supplements
- Frequent or severe infections, mouth ulcers, or fevers without a clear cause
- Unexplained bruising, petechiae, or bleeding, reflecting a low platelet count
- Drenching night sweats or unintentional weight loss
- Bone pain, swollen lymph nodes, or a swollen abdomen from an enlarged spleen
Because CBCs are part of routine antenatal care, many cases are first picked up in the lab. Our article on recognizing signs of leukemia in blood work explains what those results can look like.
Diagnosis During Pregnancy
Diagnosing leukemia in pregnancy uses the same tests as outside pregnancy, and they are safe for the baby.
- CBC and blood film to look at counts and cell appearance.
- Bone marrow aspiration and biopsy, usually from the back of the hip bone, done under local anesthetic.
- Flow cytometry, cytogenetics, and molecular tests to identify the exact type, such as the BCR-ABL1 fusion in CML.
- Clotting tests, because some leukemias, particularly acute promyelocytic leukemia, can cause dangerous bleeding.
- Imaging, when needed, favors ultrasound and MRI, with abdominal shielding for any essential X-ray.
CML can be symptom-free early on, so it is often found through a routine high white count. Our article on diagnosing chronic myeloid leukemia explains the steps.
Managing Leukemia During Pregnancy
Treatment of leukemia during pregnancy balances the mother’s survival against fetal safety. Acute leukemia generally cannot wait until delivery, because delay can be life-threatening for the mother, and a very sick mother also endangers the baby.
First trimester
This is when the baby’s organs form, and chemotherapy carries the highest risk of birth defects and miscarriage. For acute leukemia diagnosed in the first trimester, the team will have a frank discussion about options, including whether to continue the pregnancy. Some drugs, such as methotrexate and all-trans retinoic acid (ATRA), are specifically avoided in early pregnancy where possible.
Second and third trimesters
After the first trimester, many standard chemotherapy drugs can be given with lower risk of malformations. For AML, standard induction regimens are often used. There remains a risk of growth restriction, preterm birth, and low blood counts in the newborn, so the pregnancy is monitored closely with ultrasound.
Chronic myeloid leukemia
CML is often more manageable in pregnancy. Tyrosine kinase inhibitors, the usual treatment, are generally stopped during pregnancy because of concerns about fetal harm. Counts may instead be controlled with interferon-alpha or by removing excess white cells through leukapheresis, with TKIs restarted after delivery.
Delivery and after birth
Delivery is timed, where possible, to avoid the low-count period a few weeks after chemotherapy, reducing infection and bleeding risk for mother and baby. Breastfeeding is usually not advised during chemotherapy. The newborn is checked for low blood counts, and the placenta may be examined.
When to See a Doctor
Contact your obstetric team promptly if you are pregnant and notice any of the following:
- Fever, chills, or infections that keep coming back
- New bruises, pinpoint red spots, or bleeding that is hard to stop
- Tiredness or breathlessness that is getting worse despite iron
- Night sweats, weight loss, or bone pain
Most of these symptoms turn out to have a pregnancy-related or simple cause, but a CBC is quick and can rule out something serious. For wider context, see our leukemia guide.
Frequently Asked Questions
Can leukemia pass to the baby?
Transmission of leukemia from mother to baby is extremely rare. The placenta acts as a strong barrier. Doctors may still examine the placenta and check the newborn’s blood as a precaution.
Is a bone marrow biopsy safe during pregnancy?
Yes. It is done from the hip bone under local anesthetic and does not involve radiation. It is the key test for confirming leukemia and choosing treatment.
Can I have chemotherapy while pregnant?
Often, yes, especially after the first trimester. Many chemotherapy drugs can be given in the second and third trimesters with careful monitoring. Your team will choose drugs and timing to protect both you and your baby.
Is low platelet count in pregnancy a sign of leukemia?
Usually not. Mild low platelets late in pregnancy, called gestational thrombocytopenia, is common and harmless. A severe drop, a drop early in pregnancy, or low platelets with other abnormal counts needs further testing.
Can I get pregnant after leukemia treatment?
Many people do. Some treatments affect fertility, so options like egg or embryo freezing are best discussed before treatment starts when time allows. Your hematologist can advise how long to wait after finishing treatment.
