Few things in pregnancy cause as much fear as vaginal bleeding. Vaginal bleeding, while often serious, can also occur from causes that are not alarming or pregnancy-threatening. Vaginal bleeding should never be ignored, though. Your medical practitioner can determine whether or not vaginal bleeding in pregnancy is serious.
Implantation
When the embryo burrows into the uterine wall, a small amount of bleeding can occur. This generally occurs 10 to 14 days after ovulation, or around the time of a missed period, the Mayo Clinic reports. Implantation bleeding is usually scant, dark brown and lasts only a few days.
First Trimester Loss
Miscarriage in early pregnancy is common, affecting 20 percent of all women, according to the What to Expect website. Not all bleeding episodes in early pregnancy progress to miscarriage. In 50 percent of cases, bleeding stops and pregnancy proceeds normally. If miscarriage is inevitable, bleeding increases and is accompanied by severe cramping. Ectopic pregnancy, a pregnancy implanted outside the uterus, also causes vaginal bleeding as the fallopian tube, the usually location for ectopics, begins to rupture. Ectopic pregnancy is a medical emergency that can lead to maternal death if it is not recognized early.
Subchorionic Bleed
A subchorionic bleed, also known as a subchorionic hemorrhage or hematoma, occurs when a small amount of blood accumulates in the layers of the placenta, or between the placenta and the chorion, the outer fetal membrane. A small amount of spotting or bleeding may occur. Most resolve spontaneously, but large bleeds may increase the risk of placental abruption or preterm labor, according to What to Expect.
Placental Abruption
Placental abruption occurs when part or all of the placenta comes loose from the uterine wall. The torn blood vessels that attach the placenta to the uterus may bleed heavily. Blood accumulates in the abdominal cavity, causing pain that may be severe. If a large section of the placenta separates, oxygen may not get to the baby, and fetal death can occur. Maternal hemorrhage is also a possibility. Placenta abruption, which occurs in one in 120 births, according to the University of Virginia Health System, is a medical emergency that requires immediate evaluation.
Placenta Previa
Placenta previa, the implantation of the placenta on the lower part of the uterine wall, causes painless bleeding. Many placentas first implant low in the uterus but generally migrate upward as the uterus grows. In one out of 200 cases, the placenta remains close to or covers the opening on the uterus, the cervix, the University of Virginia Health System reports. Movement of the cervix or dilation causes blood vessels to tear. Severe bleeding may occur, threatening both mother and baby. Prompt medical treatment will help prevent fetal loss or maternal hemorrhage.
Labor
Both preterm labor and labor after 37 weeks can cause bleeding. The mucus plug, which fits into the cervix and keeps bacteria out of the uterus, is passed as the cervix starts to dilate, the Mayo Clinic explains. Small blood vessels in the cervix tear, causing the plug to be blood-tinged. As labor progresses, bleeding often increases. Bleeding before 37 weeks always needs investigation; scant bleeding after 37 weeks that accompanies the loss of the mucus plug is not serious.
About this Author
Sharon Perkins has worked as a registered nurse in oncology, labor/delivery, neonatal intensive care, infertility and ophthalmology. Perkins started writing professionally for the Wiley “Dummies” series in 2001, and has co-authored seven books for the series, and acted as developmental editor for several more. Perkins received her registered nursing degree from Western Oklahoma State College in 1986.
