If you are pregnant, you can no longer have your period. During menstruation, the uterus sheds its lining, which has built up in anticipation of pregnancy. There are many other reasons why women may experience bleeding or spotting during pregnancy. While some causes like implantation bleeding are normal, others may be a cause for concern.
Read on to learn more about pregnancy, periods, and other causes of bleeding while pregnant.
Periods and pregnancy
Menstruation occurs due to the changes in our hormones. During the first part of the menstrual cycle, one of the ovaries prepares to release an egg. The hormones in the body cause the lining of the uterus to build up in preparation for the fertilized egg to attach itself to the uterine lining.
When there is no fertilized egg, the estrogen and progesterone levels drop, which causes the shedding of the uterine lining. The drop in these hormones leads to prostaglandin production, which causes uterine contraction, and you experience period bleeding.
If your egg is fertilized, it will be implanted into the uterine lining and start growing and developing. You will not experience menstrual bleeding any more. Some people claim they got their periods even when they were pregnant, which is not possible. The bleeding they experienced could have been due to some other causes like implantation bleeding.
Bleeding after pregnancy can also be a sign of ectopic pregnancy or miscarriage. You must call your OB/GYN and get it checked.
Bleeding during the first trimester
Vaginal bleeding or spotting is common during the first trimester. Around 20% of women experience slight bleeding or spotting during the first 12 weeks of their pregnancy (1). Most of them go on to have a healthy pregnancy. Some of the common reasons why women experience spotting or bleeding during the first trimester include –
1. Implantation bleeding
Implantation bleeding is often mistaken for periods as it occurs around the same time as your period. This type of bleeding occurs six to 12 days after your conceive when the fertilized egg implants into the lining of the uterus. This bleeding is usually very light and can last for a few hours or a few days.
2. Changes in the cervix
Pregnancy hormones can cause some changes in the cervix (the opening to the uterus that sits on top of the vagina), causing slight bleeding. During the early stages of pregnancy, the cervix gets an increased blood supply and becomes softer, which can cause bleeding, especially after sex.
Sometimes bleeding or spotting during the first trimester can be a symptom of a serious problem. These include –
Miscarriage is common during the first 12 weeks of pregnancy, which is why women often worry when they experience bleeding at this stage. However, bleeding at this stage does not necessarily mean that you have miscarried. Almost 90 % of the women who experience the first trimester bleeding do not miscarry (2).
If a woman does miscarry, she will also experience symptoms like intense cramps during bleeding and passing of tissue through the vagina.
2. Ectopic pregnancy
The first signs of an ectopic pregnancy are a pain in the lower abdomen and vaginal bleeding. During ectopic pregnancy, a fertilized egg implants itself outside the uterus (usually the fallopian tube) and keeps growing. This kind of pregnancy can cause the fallopian tube to burst and can be life-threatening.
3. Molar pregnancy
During this rare condition, an abnormal mass of tissue grows inside the uterus instead of a baby. In some rare cases, this tissue can also be cancerous and can spread to other parts of the body. Other than vaginal bleeding, molar pregnancy can also cause nausea, vomiting, and rapid enlargement of the uterus.
Bleeding during the second and third trimester
Bleeding or spotting can also occur during the second and third trimester. Call your doctor as soon as you notice bleeding during this stage of your pregnancy. The causes of bleeding during second and third trimester include –
1. Cervical examination
During your regular prenatal visits, your doctor may inspect the cervix to check for abnormalities. This procedure can sometimes cause minor bleeding.
2. Sexual intercourse
Most women continue to have sex during pregnancy unless their doctor advises them against it due to some complications. These women may experience some bleeding or spotting due to the increased sensitivity of the cervical or vaginal tissue.
Bleeding during the second and third trimester can also be a sign of a more serious medical problem. These include –
3. Placenta previa
This medical condition occurs when the placenta sits low in the uterus and partially or wholly covers the cervix. Placenta previa can hinder labor and delivery. A bleeding placenta previa requires immediate medical attention.
4. Placental abruption
In some rare cases, the placenta can detach from the wall of the uterus before or during labor, and blood can start to pool between the placenta and uterus. High blood pressure can increase the risk of placental abruption. This condition causes severe abdominal and back pain and can be very dangerous for the mother and the child.
5. Uterine rupture
Sometimes the muscle of the uterus can tear or separate during the pregnancy. This tear usually happens along the scar lines of a previous C-section. Other than bleeding, the symptoms include pain and tenderness in the abdomen. This situation can be dangerous, and it requires an emergency C-section.
6. Vasa Previa
Vasa Previa is a condition in which the developing baby’s blood vessels cross or run near the opening of the uterus. These blood vessels are at risk of rupture, causing the baby to bleed and lose oxygen. This condition can also lead to abnormal fetal heart rate.
7. Premature labor
Vaginal bleeding late in pregnancy can also be a sign of preterm labor. If the symptoms of labor begin before the 37th week of pregnancy, it is known preterm labor. Some of the other symptoms of preterm labor include backache, a feeling of pressure on the vagina, and changes in discharge.
What to do if you have bleeding during pregnancy?
Call your doctor. Vaginal bleeding during any stage of pregnancy can be a sign of a bigger problem. Wear a pad so that you can track how much you are bleeding. If you pass any tissue through your vagina, bring it to the doctor for testing. Your doctor will perform a vaginal and abdominal ultrasound to find the cause of the problem.
If you experience pain, cramping, heavy bleeding, fever, or dizziness, rush to the emergency room or call 911. These can be signs of a miscarriage or one of the conditions mentioned above.
You cannot have your periods when you are pregnant. There are many other reasons why women may bleed during pregnancy. Some of these causes like implantation bleeding and cervical changes are normal and are not a cause for worry. Some of the other reasons include severe health conditions, and they require immediate medical help. These include miscarriage, ectopic pregnancy, molar pregnancy, infection, placental abruption, placenta previa, uterine rupture, vasa previa, and preterm labor.