Noticing vaginal bleeding during the first three months of pregnancy can be worrying. Light spotting or brown discharge does not necessarily mean a miscarriage, but the colour or amount of blood alone cannot tell you whether everything is well. For expectant mothers in Hong Kong, seeking medical advice early to confirm the pregnancy’s location and the embryo’s development is more important than trying to work out the cause yourself.
Who needs to be particularly cautious?
For women aged 35 or above, the risk of miscarriage increases with age, largely because chromosomal abnormalities in the embryo become more common. Women who have had a previous miscarriage, particularly recurrent miscarriages, also need careful assessment if bleeding occurs. However, a history of miscarriage does not mean the current pregnancy will necessarily have problems.
Women who have previously had an ectopic pregnancy, fallopian tube surgery or a pelvic infection are at greater risk of an ectopic pregnancy, where the pregnancy develops outside the womb. Those who conceive through assisted reproductive treatments, such as IVF, should also have the pregnancy’s location confirmed early. Poorly controlled diabetes or thyroid disease may increase the risk of miscarriage as well.
These are risk factors for miscarriage or ectopic pregnancy, not causes of bleeding unique to women in Hong Kong. Even without these medical histories, bleeding during pregnancy should not be ignored.
What can cause the bleeding?
The cervix can bleed more easily during pregnancy, sometimes causing light spotting after sex. Cervical polyps or infections can also cause bleeding. This bleeding may not come from the developing pregnancy itself, but an examination is still needed to confirm the cause. It should not automatically be dismissed as “implantation bleeding”.
Another possible cause is a subchorionic haematoma—a collection of blood around the pregnancy sac. Some gradually resolve on their own. Your doctor will arrange monitoring according to the haematoma’s size and location, and your symptoms.
If bleeding occurs but an ultrasound shows that the pregnancy is developing normally inside the womb, this may be described as a threatened miscarriage. Despite the name, it does not mean a miscarriage has happened. Around half of early miscarriages are associated with chromosomal abnormalities in the embryo and are usually not caused by work, everyday activities or a brief period of emotional upset. Ectopic pregnancy and the less common molar pregnancy, involving abnormal pregnancy tissue, require specialist care.
What are the potential effects on the baby?
Bleeding is a symptom; it does not in itself mean that the baby will develop birth defects. If the bleeding comes from the cervix and the embryo is developing normally, the pregnancy may continue without problems. Many women who experience a threatened miscarriage also go on to have a healthy baby.
If the bleeding is associated with a miscarriage, the pregnancy may not continue. An ectopic pregnancy cannot develop normally through to birth and may rupture, causing internal bleeding in the mother. Some studies have linked subchorionic haematomas with an increased risk of miscarriage or complications later in pregnancy. However, evidence about risks such as premature birth is inconsistent, so a haematoma alone cannot predict the outcome.
What should you do?
Contact your obstetrician promptly if bleeding occurs. Keep a record of how much you are bleeding, how long it lasts and whether you have abdominal pain. Use a sanitary pad to monitor the amount, and do not take medicines marketed to “save the pregnancy” or Chinese herbal remedies without medical advice.
Your doctor may arrange an ultrasound and blood tests. Very early in pregnancy, a single assessment may not provide a clear answer, so it is important to attend any follow-up appointments.
If you have heavy bleeding, severe or one-sided abdominal pain, shoulder-tip pain, dizziness or fainting, go to an Accident and Emergency Department immediately. Call 999 if your condition is severe. Do not wait for your next Maternal and Child Health Centre appointment.
Get adequate rest and adjust your activity level according to medical advice. There is currently insufficient evidence that prolonged bed rest prevents miscarriage. If you have had a previous miscarriage, are bleeding in the current pregnancy and an ultrasound has confirmed a pregnancy inside the womb, ask your doctor whether progesterone treatment may be appropriate.
Above all, seek assessment early, attend follow-up appointments and do not blame yourself for the bleeding.
This article is for general health education and does not replace an individual medical assessment.