Some patients treated by transplantation of haemopoietic stem cells (peripheral blood or bone marrow) become permanently infertile, but others retain or recover fertility. We assessed the outcome of conception in women, and partners of men previously treated by autologous or allogeneic stem cell transplantation (SCT).

We sent questionnaires to 229 centres of the European Group for Blood and Marrow Transplantation. We sought details about the original disease, transplant procedure, and outcome of conception for both male and female patients.

199 centres gave information relating to 19 412 allogeneic and 17 950 autologous transplant patients. 232 (0·6%) patients conceived after SCT. Crude annual birth rate for 4-month survivors of SCT was lower than the national average for England and Wales at 1·7 per 1000 patients. 312 conceptions were reported in 113 patients (74 allograft) and partners of 119 patients (93 allograft). Most pregnancies were uncomplicated and resulted in 271 livebirths. 28 (42%) of 67 allograft recipients had caesarean section compared with 16% in the normal population (difference=26% [95% CI 15–38]), 12 (20%) of 59 had preterm delivery compared with a normal rate of 6% (14% [4–24]), and 12 (23%) of 52 had low birthweight singleton offspring compared with a normal rate of 6% (17% [6–29]).

Pregnancy after SCT is likely to have a successful outcome. Pregnancies in allograft patients who have received total body irradiation should be treated as high risk for maternal and fetal complications.