women s health issues
Vaginal Bleeding During Late Pregnancy
Causes of Vaginal Bleeding in Late Pregnancy
Themost common causeof bleeding during late pregnancy is The start of labor In late pregnancy, some women pass the mucus plug (collection of mucus in the cervix) through the vagina. The mucus plug is usually a sticky small ball and often has streaks of blood in it. Passing the mucus plug is not the start of labor, but it is often a signal that labor will begin within the next week. Usually, labor starts with a small discharge of blood mixed with mucus from the vagina. This discharge, called the bloody show, occurs when small veins are torn as the cervix begins to open (dilate), enabling the fetus to pass through the vagina. The amount of blood in the discharge is small. More serious but less common causes(see table) include the following: Placenta Previa None Vasa Previa (rare) Placental Abruption None Uterine Rupture (rare) Inplacenta previa,the placenta is attached to the lower rather than the upper part of the uterus. When the placenta is lower in the uterus, it may partly or completely block the cervix (the lower part of the uterus), which the fetus must pass through. Bleeding may occur without warning, or it may be triggered when a practitioner examines the cervix to determine whether it is dilating or whether labor has started. Placenta previa accounts for approximately 20% of bleeding during late pregnancy and is most common during the 3rd trimester. The placenta may be low-lying earlier in pregnancy, but the placenta usually moves out of the way on its own before the 3rd trimester. Vasa previais a rare condition in which the blood vessels that provide blood to the fetus (through the umbilical cord) grow across the cervix, blocking the fetus's passageway. When labor starts, these small blood vessels may be torn, depriving the fetus of blood. Because the fetus has a relatively small amount of blood, loss of even a small amount can be serious, or even fatal, for the fetus. Inplacental abruption,the placenta detaches from the uterus before delivery. What causes this detachment is unclear, but it may occur because blood flow to the placenta is inadequate. Sometimes the placenta detaches after an injury, as may occur in a car crash. Bleeding may be more severe than it appears because some or most of the blood may be trapped behind the placenta and thus not be visible. Placental abruption is the most common life-threatening cause of bleeding during late pregnancy, accounting for approximately 30% of cases. Placental abruption may occur at any time but is most common during the 3rd trimester. may occur during labor. It almost always occurs in women whose uterus has been damaged and contains scar tissue. Such damage may occur during a cesarean delivery or other uterine surgery (such as myomectomy to remove Fibroids During Pregnancy ). Bleeding may also result from disorders unrelated to pregnancy. Various conditions (risk factors) increase the risk of disorders that can cause bleeding during late pregnancy. Forplacenta previa,risk factors include the following: A Cesarean Delivery in a previous pregnancy One or more previous pregnancies A Multiple Births None Placenta Previa in a previous pregnancy Age over 35 Cigarette smoking In vitro (test tube) fertilization (IVF) (fertilization of the egg in a laboratory and placement of the embryo in the uterus) Forvasa previa,risk factors include the following: A placenta located low in the uterus A placenta that is divided into sections A Multiple Births None In vitro (test tube) fertilization (IVF) None Forplacental abruption,risk factors include High Blood Pressure None Age over 35 One or more previous pregnancies Smoking (Tobacco) None Use of Cocaine None Placental Abruption in a previous pregnancy A recent abdominal injury (as may occur in a car accident) Forrupture of the uterus,risk factors include the following: A Cesarean Delivery in a previous pregnancy Any prior surgery involving the uterus Age over 30 Previous infections of the uterus Artificial starting (induction) of labor Injury, as may occur in a car crash Birth of more than five babies Pregnancies that are too close together Placenta Accreta (a placenta that grows too deeply into or through the uterus) 