I apologize if someone has already answered the question about sickle cell trait
and nosebleeds, but I'm a little behind reading lactnet. The persons who have
SCT are heterozygous for Hemoglobin S and are essentially asymptomatic. Symptoms
resulting from occlusion occur only in extreme circumstances of severe hypoxia.
Painless hematuria( blood in urine)  can also occassionally be observed in
persons with sickle cell trait but other more common causes should be ruled out.
I have sickle cell trait, and breastfed four children without any problem. The
case of a women with nosebleeding while breastfeeding probably is not related to
SCT.

Ana M. Parrilla, M.D., M.P.H., IBCLC
LLLI Medical Associate
Medical Director Lactamar - Instituto de Lactancia Materna
San Juan, Puerto Rico