Decidual bleeding is a term for a partial shedding of the uterine lining during the first few months of pregnancy. This bleeding can be similar to a menstrual period and can occasionally prevent women from realizing that they are pregnant until other signs develop. Although this kind of bleeding is usually harmless, most experts recommend that pregnant women inform their doctors about any form or amount of vaginal bleeding as it can be a sign of more serious conditions.
During early pregnancy, quick hormonal shifts in the body can cause ovulation or the thickening of the uterine lining despite the presence of a fertilized egg. Around the time of a women’s normal menstrual period, the lining can shed, resulting in bleeding. For some women, the amount of blood released can resemble an normal period. For this reason, some experts recommend that anyone with other pregnancy signs, such as regular nausea, increased breast size or tenderness, or sudden weight gain, take a pregnancy test even if menstrual cycles appear normal. If an over the counter test proves positive despite the presence of bleeding, consider consulting a doctor for a more accurate confirmation of pregnancy.
Decidual bleeding is sometimes confused or used synonymously with implantation bleeding, another phenomena of early pregnancy. Implantation bleeding is characterized as a light spotting that is the result of the egg implanting in the uterus. Like decidual bleeding, implantation bleeding can cause women to believe they are not pregnant and are experiencing a normal menstrual period. Because of this similarity, and the fact that both types of bleeding are considered largely harmless, both implantation and decidual bleeding are often referred to collectively as first-trimester bleeding.
In most cases, this condition is not harmful to either the mother or fetus. Although figures vary, some experts suggest that harmless vaginal bleeding occurs in up to 30% of pregnancies. Most women who experience this type of bleeding during pregnancy go on to have healthy pregnancies and deliveries.
Despite the relative harmlessness of this type of bleeding, most experts urge that women experience any bleeding during pregnancy inform a health care provider immediately. Bleeding can be a sign of several conditions that can adversely affect health, such as cervical cancer, impending miscarriage, ectopic or molar pregnancies, or cervical or vaginal infections. If bleeding continues longer than a day or is heavy, a doctor may request an examination to check the health of both mother and fetus and rule out possible complications.