Maternal Use of Estrogen Hormonal Contraception Just Before Pregnancy – A Risk for Childhood Leukemia?

In a well done and very interesting study in Lancet Oncology, Danish researchers have identified an association between use of estrogen-containing oral contraceptives in the three months prior to pregnancy or during pregnancy and the risk of childhood leukemia in the offspring of that pregnancy. The study’s conclusions are strengthened by the fact that the data come from three reliable nationwide Danish databases –  one registering births, one registering cancers and the other registering prescriptions –  and included over a million children born between 1996 and 2014, with a median of 9 years follow up from birth. How high is the risk? The hazard ratio for childhood leukemia was about 50%-70% higher among children born to women taking estrogen-containing contraceptives in the three months prior to or during pregnancy, compared to that in the offspring of women not using these contraceptives immediately before or during pregnancy. The risk was confined to non-lymphoid leukemias. Because the overall risk of leukemias is low (most children do NOT develop leukemia), the actual risk translates to one extra case of leukemia for every 50,000 potentially exposed children, or in Denmark, about 4% of leukemia cases over the 9 years studied. That’s not a large risk, but it is worth looking at. Which hormonal contraceptives were implicated? The risk for childhood leukemia was only found for use of estrogen-containing oral contraceptives in the 3 months just pr...
Source: The Blog That Ate Manhattan - Category: Primary Care Authors: Tags: Best of Birth Control Posts Best of TBTAM Family Planning How to Get Pregnant birth control pills hormonal contraception Leukemia risks Source Type: blogs