Many women with low platelets are concerned about having a family. A low platelet count does not prevent a woman from becoming pregnant or delivering a fine, healthy baby. However, the situation does require special attention and close coordination between the woman’s hematologist, obstetrician, and pediatrician.
Sometimes a low platelet count is discovered when a woman is pregnant. If that’s the case, it is important to determine if the low platelet count is associated with pregnancy (gestational thrombocytopenia) or due to another cause, such as ITP. The journal article, "How I treat thrombocytopenia in pregnancy" contains information on how to tell if low platelets in pregnancy are due to ITP or some other cause and the best way to treat the condition.
Treatment for ITP during pregnancy
If a woman has ITP and becomes pregnant, her platelet count may drop in the third trimester or she may relapse. However, treatments such as IVIg or prednisone can be given to raise the platelet count for delivery. Some treatments that are used for ITP, particularly those that suppress the immune system (except azathioprine) or stimulate platelet production, are not good options for pregnant women because they could harm the fetus. The thrombopoietin mimetics (TPO agents) are not recommended during pregnancy because they can cross the placenta. Women should wait up to a year after Rituxan treatments end before becoming pregnant.3 Some studies link prenatal corticosteroids (ex. prednisone) to mental health problems later in the child's life.4
There is no evidence that a cesarean is safer for the baby in a mother with a low platelet count, so the decision to have a vaginal birth or cesarean should be based on the best method of delivery given the mother’s circumstances.1 Most physicians recommend maintaining a platelet count above 20,000 to 30,000 platelets per microliter throughout pregnancy and above 50,000 near term. A higher count between 80,000 and 100,000 per microliter would be required for an epidural anesthesia.
Only a very small percent of babies born to mothers with ITP have low platelets at birth. Attempting to measure the platelet count of the fetus carries significant risk, so it is not advised. However, it is fine to do a cord blood count after delivery.2
Breastfeeding can be safely accomplished following pregnancies complicated by ITP or gestational thrombocytopenia. There is concern among some physicians because anti-platelet antibodies can be passed to the newborn in the breast milk of ITP mothers. However, there is no evidence that children breastfed by ITP mothers are at elevated risk. If the newborn's low platelet count persists, it might be helpful to stop breastfeeding.5
1. Letsky EA, Greaves M. “Guidelines on the investigation and management of thrombocytopenia in pregnancy and neonatal alloimmune thrombocytopenia. Maternal and Neonatal Haemostasis Working Party of the Haemostasis and Thrombosis Task Force of the British Society for Haematology.” Br J Haematol. 1996 Oct;95(1):21-6. http://www.ncbi.nlm.nih.gov/pubmed/8857933
2. Burrows RF, Kelton J. “Pregnancy in patients with idiopathic thrombocytopenic purpura: assessing the risks for the infant at delivery.” Obstet Gynecol Surv. 1993 Dec;48(12):781-8. http://www.ncbi.nlm.nih.gov/pubmed/8309660
3. Chakravarty EF et al. “Pregnancy outcomes after maternal exposure to rituximab.” Blood. 2011 Feb 3;117(5):1499-506. http://www.ncbi.nlm.nih.gov/pubmed/21098742
4. Khalife N et al. “Prenatal Glucocorticoid Treatment and Later Mental Health in Children and Adolescents.”PLOS ONE. 2013 Nov. 22. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0081394
5. Hauschner H et al. “Persistent neonatal thrombocytopenia can be caused by IgA anti platelet antibodies of breast milk of immune thrombocytopenic mothers.” Blood. 2015 Jun 15. http://www.ncbi.nlm.nih.gov/pubmed/26077397