In the first trimester (before 12 weeks): This is very common. It occurs in more than 30 percent of pregnancies. Our greatest concern is that this would be a sign of a tubal pregnancy which can be a medical emergency. Fortunately, tubal pregnancies are uncommon (less than 2 percent).
The next and more common concern is: does this mean the pregnancy is not viable? Is it the sign of an impending miscarriage? Around 50 percent of the time, this is the case. Nonviable pregnancies may be diagnosed via ultrasound. If the pregnancy is too early for ultrasound, serial blood determinations of the HCG level may be done over several days. During office hours, we typically perform an exam and ultrasound and obtain blood samples.
If bleeding occurs after hours and you are concerned about the volume bleeding or the possibility of tubal pregnancy, we will direct you to the emergency room. If bleeding volume is light, the patient is encouraged to follow-up during office hours where an evaluation can be done. It is important to note that in the case where bleeding is seen, there is no intervention that can change a nonviable pregnancy to a viable one.
Bleeding in the second and third trimester (after 12 weeks): A small amount of bleeding and spotting is normally seen at term after cervical exams and as the cervix thins. Commonly, it represents trauma or irritation of the vascular cervix especially if it occurs after intercourse. However, bleeding can be a sign of preterm labor especially if accompanied by regular uterine contractions or menstrual-type cramping.
Bleeding can also be the sign of placenta previa. This means the placenta is blocking the cervix. This is evaluated and ruled-out during the ultrasound around 20 weeks.
Lastly, bleeding could represent abruption of the placenta. This means the placenta separates from the wall of the uterus. This occurs most commonly in women with high blood pressure. It can also be the result of trauma to the abdomen.