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What are the causes of bleeding during pregnancy?
Bleeding before 20 weeks of pregnancy and bleeding after 20 weeks of pregnancy are the two main categories of pregnancy bleeding causes.
Before 20 weeks gestation, causes of bleeding may include:
Implantation bleeding — in very early pregnancy (4 to 5 weeks gestation) some women may experience bleeding when the pregnancy implants itself in the lining of the uterus (womb).
Miscarriage — bleeding may be the first sign of a miscarriage. About 1 in 15 women who experience bleeding in early pregnancy end up having a miscarriage.
Ectopic pregnancy — a rare but serious cause of bleeding when a fertilised egg starts growing outside the uterus (womb). An ectopic pregnancy can rupture (burst) and cause heavy bleeding, and may be life-threatening.
After 20 weeks of pregnancy, bleeding is typically brought on by issues with the placenta, such as:
Placenta previa — also known as a low lying placenta, when the placenta implants close to the cervix (neck of the uterus). If the cervix starts to open or the uterus contracts, this can cause bleeding.
Placental abruption — when the placenta starts to separate from the uterus during pregnancy but before birth, causing bleeding from the place where the placenta has peeled away. Bleeding caused by placental abruption is usually associated with sudden, severe abdominal pain.
Any stage of pregnancy may experience less frequent causes of bleeding, which include:
genital tract infections
injuries to the genital tract
growths or tumours of the reproductive system
bleeding from vulvovaginal varicosities (varicose veins in the vulva or vagina)
Is vaginal bleeding normal during pregnancy? When should I be worried about it?