Understanding Subchronic Hematoma During Pregnancy: Symptoms & Management

Question
Hello, i am 22 years old and have a two year old son with no problems in that pregnancy or the birth. I am now 15 weeks pregnant with my second child, had scan at 13 wks 2 days where they found no problems. Two days later i woke to find i had been bleeding in the night and on going to the bathroom bled VERY heavily. My midwife came out by which time the bleeding was only light and she found babys heart rate no problem. Light bleeding continued for two days then stopped and i was booked in for another scan. This showed the hematoma, measuring 75 by 63 by 19mm (14wks 6days) They said that baby seemed fine but could not tell me if it would continue to be fine and said i may go into early labour. I have been told to take it easy and that is all they will tell me. I have had no more bleeding since but have been experiencing abdominal pain (since before the scan) can you tell me any more about this condition and what are the chances of my baby being ok?
Many thanks for your time, kerry.

Answer
You have a condition called a "subchorionic hematoma" which is a sequestration  of blood between two layers of the placenta (the amnion and chorion). It is a blood clot formed while the placenta was forming and is usually self limited and will dissipate on its own. It usually does not have any effect on the growth of the baby and poses no danger to the baby. It does not cause preterm labor, but you should always be on the lookout for preterm labor, in any case. The bleeding will get less and less and it should resolve on its own. If, on the other hand, you start to bleed heavily with menstrual-like cramping, call your midwife right away. For now, just take it easy, avoid sexual intercourse and heavy lifting, and, as long as the fetal heart remains positive, you should be fine.