It is known that the developing fetus in the mother’s womb is enclosed from outside with membranes. One of these outer membranes, between the mother’s uterine wall and the embryo, is called as the chorion.
A subchorionic bleed, also known as a subchorionic hematoma, occurs when there is accumulation of blood between this chorion and the uterine wall, or under the placenta itself. This often, but not always, causes spotting and vaginal bleeding in the mother, and can be a cause of anxiety to the expecting mother.
Almost 1% of all pregnant women develop subchorionic bleeding.
More than often, this may not be a cause to worry as the bleeds heal up by themselves. In 20% cases of the first trimester bleeding, it is because of the hematoma formation. Most of these go ahead into healthy pregnancies. In some cases, there may be no spotting at all. Such subchorionic hematomas often go undetected or may get noticed on the ultrasound examination during a routine check-up.
If this happens, the doctor may advise to the mother to take rest and avoid stress for a few days, and schedule regular follow-ups till the hematoma resolves on its own. The hematomas usually are regarded as benign unless the bleeding worsens, or when the mother may experience a soak-the-pad bleeding, that is, free bleeding as in menses.
This may be an early sign of miscarriage and should be reported to the doctor immediately, without any further delay. The doctor may then advise ultrasound examination, to check the status of the baby and for the heart sound and rate. Hearing a normal heart sound here can be quite reassuring. Though, as previously stated, most of the subchorionic bleeds in pregnancy are resolved in time, there are few that may grow in size and look threatening.
These then can apply pressure on the developing fetus, interfere with the supply of proper nutrients from the placenta to the baby, and thus hamper development. Though rare, the chances of the bursting of the hematoma cannot be ruled out. This can give rise to a dangerous internal bleeding and cause fetal damage and miscarriage. Hence, once detected, they should be constantly monitored by your doctor.
Regular ultrasound examinations for screening of any developing subchorionic bleeds is not warranted for all mothers; however, maybe required in those who are at high risk. These include women who have any history of bleeding disorders or previous history of such hematomas and spontaneous miscarriages.
Also what needs to be kept in mind is that not all the hematomas can be detected on ultrasound, and many may go unnoticed due to being small in size. The outcome of the pregnancy with a subchorionic hemorrhage depends on various other factors also-such as the age of the mother and gestational age of the fetus.
Younger mothers’ have better chances; and the prognosis for a later-stage first trimester and second trimester bleeding may not be as good. In later stages, the collected blood can cause the placenta to strip off from the uterine lining with serious complications. The best approach is prevention; and this can be done by mothers in the high–risk groups, by preventing any kind of vigorous or strenuous routines during early pregnancy stages and proper compliance to doctors’ instructions.