Subchorionic Bleeding During Pregnancy: Symptoms, Causes Treatment and Diagnosis.


Any bleeding during pregnancy raises an alarm in a parent’s mind. Theoretically there should be no bleeding during pregnancy. But studies have found that almost in 50% of pregnancies there is intermittent bleeding and it is completely normal. But sometimes bleeding indicates serious disorders. Subchorionic bleeding is one of the causes of bleeding during pregnancy.

Guide for Subchorionic Bleeding During Pregnancy

Subchorionic Bleeding During Pregnancy

What is Chorion?

Foetus is covered with two membranes. The outermost membrane is known as chorion. It later forms placenta. Foetus is attached to mother with an attachment known as placenta. Placenta is made of some part of foetus and some part of mother. It helps to exchange nutrients, wastes, antibodies and antigen from mother to the baby. This foetal part of placenta is made up of chorion.

What is subchorionic bleeding?

Subchorionic means under the chorion. Thus we can know that subchronic bleeding means bleeding under the chorionic layer of placenta. Actually this occurs when placenta detaches from the original site. Chorionic layer lifts apart and forms a sac between the uterus and placenta, where blood gets accumulated. It is also known as subchronic hematoma.


  • Small hematoma- when the clot is less than 20% of the gestational sac it is a small hematoma. It usually subsides on into own. It returns back to circulation within 12 weeks. It is not dangerous.
  • Medium hematoma- It is almost 20-50% of the size of gestational sac. This type of hematoma is observed regularly. To see if there is grows or regresses and then treatment is done accordingly.
  • Gigantic hematoma- the size of hematoma is more than 50% it can compress the gestational sac and create problem in the growth and development of the foetus. There are high chances of abortion. Thus proper measures have to be taken to tackle this hematoma

Causes of subchorionic bleeding

Exact causes and aetiology of subchorionic bleeding is not yet known. It happens when chorionic layer separates from placenta leading to bleeding and that blood accumulates in the sac formed between the placenta and uterus. Accumulation of blood leads to clotting of blood. Some studies have found that this happens due to thin uterine wall and weak blood vessels.


The symptoms of subchorionic bleeding are not definite. Most important and primary symptom is bleeding. While sometimes abdominal cramps are also experienced and other times, it is completely symptomless.

  • Bleeding– bleeding is intermittent. Some women experience just spotting while some experience heavy bleeding. Heavy bleeding can lead to other dangerous diseases like anaemia. Therefore proper nutrition and timely checking is very important. Other causes of bleeding may be implantation bleeding, ectopic pregnancy, miscarriage, molar pregnancy, uterine rupture. Separation of placenta or preterm labour.
  • Abdominal cramps– the bleeding in the uterus results in irritation of uterus. This irritation may cause abdominal cramps.


Ultrsasonography is the most common technique which finds the subchorionic bleeding. In the ultrasound scan clot appears as black mass with uterus. Normally a routine ultra sound is done within  6 weeks of pregnancy. It can find out signs of subchorionic bleeding. If it is found then it is observed and precautions are taken to prevent miscarriage. If heart beats are found in sonogram after 7 weeks of pregnancy then in almost 97% of the cases pregnancy is successful. If you cannot hear the sounds then don’t panic, your doctor will do the test after a week as your baby’s progress may have not reached at that point. Outcome of the pregnancy is decided by the dimension of the clot and the gap formed between the placentas.

Subchorionic bleeding at various stages

  • Subchorionic bleeding at first trimester– it is more dangerous in earlier pregnancy. As the placenta is very small. Even a smaller haematoma may separate the placenta causing miscarriage.
  • Subchorionic bleeding at second trimester– if subchorionic bleeding appears in 2nd trimester then there is a risk of a still born baby. At this stage placenta has become strong. So it is difficult to disturb the placenta. But the haematoma may decrease the blood flow to the baby. Due to which baby may become hypoxic or its growth and development may stop. At this stage the dimension of clots are seen and then precaution are taken in that direction.
  • Subchorionic bleeding at third trimester– it is rare that subchorionic may get diagnosed at 3rd It won’t affect the baby much at this stage as development of the baby is almost completes as well as the placenta is also strong.


  • Preterm labour– bleeding between the placentas may cause separation of placenta and induction of labour earlier than the delivery time. Mainly separation after 20 weeks will cause pre term labour.
  • Restriction in foetal growth-foetal growth may get restricted due to restriction of blood flow to the baby.
  • Abortion– if there is separation of placenta at early stage then it may cause abortion.


Unfortunately there is no treatment available as such. Every doctor just takes all the precautions to prevent miscarriage. Some of the ways are-

  • Complete bed rest– if there is any threat to the foetus due to the haematoma, the doctor may suggest complete bed rest. Do follow the instructions properly. Any disturbance to the abdomen may lead to separation of the placenta.
  • No heavy lifting– heavy lifting should be strictly avoided. It may lead to separation of placenta.
  • Uterine or cervical stimulants– avoid all kind of uterine stimulants, including raspberry or evening primrose oil.
  • Blood thinners– in rare cases, weighing the pros and cons, doctor may give some blood thinners, which will prevent the formation of the clot.
  • Ultrsasonography– doctor will suggest Ultrsasonography from time to time to check the growth and development of the baby as well as haematoma. Be sure to get all those done and consult your doctor.
  • Progesterone and oestrogen therapy– some doctors may give progesterone to prevent the abortion.
  • Sex– sex should be avoided during such pregnancy as placenta may get disrupted.

General care during pregnancy

It is very necessary that you take proper care of your health during pregnancy. Remember a healthy mother nurtures a healthy child. At this stage your baby is completely dependent on you for all of its needs. Hence taking proper care of your self is very important some of the points are-

  • Proper nutrition– intake of iron and protein rich diet is very essential. Iron deficiency may cause anaemia to mother as well as the baby. And protein to strengthen the amniotic sac so that the blood doesn’t enter it.
  • No heavy lifting even in normal pregnancy– weights more than 3-4 kg should not be lifted even in normal pregnancy. In pregnancy already there is lot of stress on your vertebra, picking up heavy things just adds to the stress.
  • Hydration– proper hydration is very important during pregnancy. It restores the amniotic fluid and even detoxifies your body. Drinking plenty of water also prevents and urinary tract infection.
  • Do not self prescribe any drug during pregnancy– any drug during pregnancy might be proven dangerous. A normal over the counter drug which you take normally may be proven to be life taking during pregnancy. This happens because during pregnancy metabolism of the woman changes drastically.
  • Maintain proper vaginal hygiene– maintaining vaginal hygiene is very important. May diseases are transferred to the baby through birth canal. Thus maintaining proper flora of vagina and keeping it clean is very important.

These were some points about subchorionic bleeding. Though intermittent bleeding in first trimester is nothing to be worried about but the entire screening test suggested by doctor should be done. Do not miss your antenatal visits. Doctor checks the well being of your baby in those visits. I am sure you will be exited to know how your baby is doing. So make sure to follow all the advice given by doctors. Wish you and your baby a health life!

Hope this article was of help to you! Please share your comments/queries/tips with us and help us create a world full of Happy, Healthy and Empowered Women!!