Menstrual cycle or periods mark the beginning of the reproductive phase in a woman's life. On average, a single cycle is about 28 days. Though it varies between 21 and 35 days for most women. During each cycle, an ovary (female reproductive organ) releases an egg or an ovum through a process called ovulation. After ovulation, the egg remains viable for a day or two. If fertilisation happens during this period, it leads to pregnancy. The fertilised egg gets embedded into the wall of the uterus and starts to grow. Otherwise, the inner lining of the uterus breaks down and the woman starts menstruating. The whole process is controlled by a group of hormones including progesterone and estrogen.

Missing your menstrual periods is thus one indicator that you may be pregnant and you don't get your periods during pregnancy

Although, in early pregnancy, some light bleeding, called 'spotting' may occur. It is a sign that the foetus is getting implanted in the wall of your womb. This is also known as 'implantation bleeding' and usually happens around the time that your first period after conception would have been occurring.

But there may be other reasons for bleeding during pregnancy. So, it is natural to get worried when you see blood spots while you are pregnant.

Vaginal bleeding is a frequent complication during the first trimester, which is more serious in the following trimesters. Hence, it is important to make an appointment with your doctor and find the exact cause of bleeding at the earliest.

Read more: Early signs you may be pregnant

  1. Vaginal Bleeding during pregnancy
  2. Bleeding during the first trimester
  3. Bleeding during the second and third trimester

Bleeding during pregnancy occurs for various reasons, which vary as per the gestation period. These reasons are at times serious, and at times harmless. A few of the reasons are mentioned below.

Women Health Supplements
₹719  ₹799  10% OFF

Vaginal bleeding during the first trimester of pregnancy may or may not be normal. Here is how to tell.

Implantation bleeding

Mild spotting during the first trimester can be a sign of implantation. Implantation bleeding is accompanied by light cramps, headache, mood swings, breast tenderness or lower backaches. This type of spotting is often confused with menstrual bleeding because it occurs at the time when the woman is expecting her normal periods.

(Read more: How to use a pregnancy test kit)

Miscarriage or Ectopic pregnancy

During the first three months (12 weeks) of pregnancy vaginal bleeding can also be a sign of miscarriage or ectopic pregnancy i.e. when the fetus implants outside the womb. This type of bleeding is heavier than usual menstrual periods and presents with more painful cramps.

In case of an ectopic pregnancy, one may experience dark, watery bleeding, accompanied by a sharp pain in the lower abdomen (experienced on a single side). This is often accompanied by feelings of nausea and vomiting. Ectopic pregnancy requires immediate medical attention as it can be harmful to the mother.

Other reasons for bleeding during this period include infection, subchorionic haemorrhage (bleeding occurring between the uterine wall and the placenta) or gestational trophoblastic disease (rare tumours inside the uterus) that may lead to pelvic cramps and fever.

(Read more: Chemical pregnancy symptoms)

Bleeding continuing after the first trimester is often indicative of an alarming situation. However, one may also experience minor bleeding after a cervical examination procedure by a doctor.

Various reasons for bleeding during the second and third trimester are listed below.

Placenta Previa

Placenta previa refers to a condition when the placenta is attached close to or covers the cervical opening. According to the Children’s Hospital of Wisconsin, there is a greater risk of bleeding if more of the cervical os is covered with the placenta. Risks involved with placenta previa are abnormal implantation of the fetus, slow growth of the fetus, preterm birth and post-delivery infection.

(Read more: Caring for a preterm baby)

Placental abruption

Placental abruption refers to the separation of the placenta and uterine lining. It can occur anytime after the 20th week of pregnancy and is experienced by nearly one per cent of pregnant women. According to the American Pregnancy Association, about 80% of pregnant women experience vaginal bleeding during this condition, which is accompanied by uterine tenderness, abdominal pain and abnormal heart rate of the fetus.

Once this condition is diagnosed, additional care needs to be taken depending upon the gestational period, bleeding and the condition of the foetus. Blood transfusions may be needed in case of severe blood loss.

(Read more: Ultrasound during pregnancy)

Vasa praevia

Vasa praevia refers to a condition wherein blood vessels of the foetus cross or run near the internal opening of the uterus. These blood vessels are at risk of rupturing along with the supporting membranes. Although this condition mostly occurs without any symptom, at times, vaginal bleeding during the second or third trimester may be seen.

(Read more: Check up during pregnancy)

Rupture of uterus

Uterine rupture is a rare complication, which often results in a life-threatening situation for both the mother and the foetus. The condition occurs when a muscular wall of the uterus breaks down during pregnancy and childbirth.  It is generally seen with a uterine scar developed during previous c-section deliveries or fibroid surgeries. Vaginal bleeding accompanied by sharp pain between contractions, a bulge under the pubic bone or abnormal fetus heart rate are the common symptoms.

(Read more: Pros and Cons of natural birth and a C-section) 

So, the bottom line is that there are no menstrual periods during pregnancy. If a woman is experiencing bleeding, whether mild, moderate or severe, she needs to visit a doctor immediately. Timely diagnosis and treatment would help to keep you and your baby safe and healthy.


  1. Center for Disease Control and Prevention [internet], Atlanta (GA): US Department of Health and Human Services; REPRODUCTIVE HEALTH AND THE WORKPLACE
  2. Better health channel. Department of Health and Human Services [internet]. State government of Victoria; Pregnancy - bleeding problems
  3. National Health Service [Internet]. UK; Vaginal bleeding in pregnancy.
  4. National Health Service [Internet]. UK; Miscarriage.
  5. Harville EW et al. Vaginal bleeding in very early pregnancy. Hum Reprod. 2003 Sep;18(9):1944-7. PMID: 12923154
Read on app