Causes
Early-pregnancy bleeding can originate from the uterus, cervix, or vagina, or it can come from outside the genitals. In many cases, the cause of the bleeding is due to a minor condition that requires no treatment. However, if you experience any vaginal bleeding during your pregnancy, particularly if it is associated with abdominal pain, you should consult your doctor. Possible causes of bleeding include:
- Implantation of the embryo
- Infection
- Irritation (eg, after intercourse)
- Miscarriage
- Ectopic pregnancy —the baby starts to develop outside the uterus, such as in a fallopian tube
- Molar pregnancy—usually benign formations of placental cells (trophoblasts) in the uterus that can spread to nearby tissues and become malignant
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Threatened abortion is common, with about 20-30% of pregnancies being complicated by bleeding in the first 20 weeks. About 10-15% of all established pregnancies ultimately abort (miscarry). Some factors thought to increase the risk of threatened abortion are:
- Infection
- Trauma
- Certain medications
- Advancing maternal age
