Vaginal bleeding can occur anytime in pregnancy. It is relatively common, and can occur during any trimester from conception (when the egg is fertilized) till the end of the pregnancy. Vaginal bleeding during pregnancy happens to about 15–25% of pregnant women especially during the first trimester (first 14 weeks) of pregnancy.
However, bleeding can also occur in the second and third trimester of pregnancy , so it is important to know the sign of a possible complication and get checked by an obstetrician gynaecologist to make sure you and your baby are in safe hands.
Abnormal vaginal bleeding in pregnancy is defined as bleeding during pregnancy that is usually as heavy as the bleeding you have on the second day of your menstrual period.
Causes of vaginal bleeding during early pregnancy (first trimester)
Bleeding in early pregnancy can be caused by some minor problem such as;
- Sexual intercourse in pregnancy
- Infection of the cervix, vagina or a sexually transmitted infection (such as chlamydia, gonorrhoea, or herpes)
- Implantation of a fertilized egg in the lining of the uterus which happens around the time of the menstrual period. Implantation bleeding may occur before a woman realizes she is pregnant.
- Changes in hormone
- Cervical changes
Miscarriage or early pregnancy loss is the most common cause of vaginal bleeding which occurs during the first 12 weeks of pregnancy. It does not necessarily mean the pregnancy will be lost or miscarried. If a miscarriage occurs with the current pregnancy, most women will go on to have a future healthy pregnancy. Signs of Miscarriage include
- Vaginal bleeding
- Cramping pain felt in the lower abdomen (stronger than menstrual cramps)
- Tissue passing through the cervix and vagina
- Back pain
Threatened miscarriage occurs as a result of abnormal bleeding and abdominal pain that occurs while the pregnancy continues, anything other than spotting during the first trimester may be considered a threatened miscarriage. i.e. spontaneous pregnancy loss. Symptoms of a threatened miscarriage are bleeding and mild cramping, but the cervix is closed, and the foetus survives.
Ectopic pregnancies are less common than miscarriages, but potentially dangerous and life-threatening, fertilized embryo is implanted outside the uterus, located within one of the fallopian tubes. The fallopian tube accounts for most ectopic pregnancies. this sometimes is referred to as a tubal pregnancy, which means that as the pregnancy grows and the tube distends, abdominal pain becomes increasingly severe and as a result of this, sometimes the pregnancies can rupture the Fallopian tube, leading to major blood loss and in most cases a blood transfusion and emergency surgery are needed. Major signs and symptoms of ectopic pregnancy are;
- Cramping pain felt in the lower abdomen (usually stronger than menstrual cramps)
- Low levels of HCG
- Abdominal pain
- Absence of menstrual periods
- Spotting (vaginal bleeding or intermittent bleeding)
- Light-headedness or dizziness
Women with higher risk may have had:
- An infection in the tubes
- previous ectopic pregnancy
- Previous pelvic surgery
Causes of vaginal bleeding during pregnancy (second and third trimesters)
Bleeding or spotting in second and third trimester can be as a result of;
- Sexual intercourse or having a pelvic examination internally by your OB/GYN or midwife
- Cervical problems such as cervical insufficiency or incompetency (when the cervix opens too early in pregnancy) and
- cervical infection
Major or severe causes of bleeding in later pregnancy include
- Placenta previa
- Preterm labour
- Uterine rupture
- Placental abruption.
It is appropriate and advisable to call your OB-GYN doctor if abnormal vaginal bleeding is noticed. It is particularly important to seek medical attention if the bleeding is heavy (like a menstrual period), becomes painful or crampy.