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While it can be concerning, many subchorionic haematomas resolve on their own without causing complications. Understanding the causes, symptoms, risks, diagnosis, and treatment options can help you navigate this condition with confidence.
What is Subchorionic Bleeding?
Subchorionic bleeding occurs when the chorionic membrane partially detaches from the uterine wall, allowing blood to pool in the space between the two. This detachment creates a haematoma, which may lead to vaginal bleeding as the blood leaks through the cervical canal. The size of the haematoma can vary, and it is classified based on its proportion to the gestational sac:- Small: Less than 20 per cent of the gestational sac size.
- Medium: 20 to 50 per cent of the gestational sac size.
- Large: Greater than 50 per cent of the gestational sac size.
Symptoms of Subchorionic Bleeding
Vaginal bleeding is the most common symptom of subchorionic bleeding that occurs in 25 per cent of individuals during the first half of pregnancy. The bleeding can vary in severity, from light spotting to heavy flow with clots. In some cases, you may experience pelvic cramping, though this is less common. However, many individuals with subchorionic haematomas have no symptoms at all.If you notice any vaginal bleeding during pregnancy, it’s important to contact your healthcare professional to determine the cause and rule out other serious conditions.Risks of Subchorionic Bleeding
Several factors may increase your risk of developing a subchorionic haematoma, including:- Uterine abnormalities: Malformations of the uterus can contribute to the detachment of the chorionic membrane.
- History of recurrent miscarriages: People with previous pregnancy losses may be at higher risk.
- Pelvic infections: A history of infections in the pelvic region may increase your chances of developing this condition.
- Trauma: Physical trauma to the abdomen can trigger bleeding.
- Severe hypertension: Chronic high blood pressure can affect placental attachment.
- In vitro fertilisation (IVF): Subchorionic haematomas are more common in IVF pregnancies compared to non-IVF pregnancies. They are especially common with fresh embryo transfers, blastocyst transfers, or in individuals with a parity of one or greater.
Possible complications include:
- Miscarriage: There is a small risk of pregnancy loss, especially with larger haematomas or those detected early in pregnancy (before 7 weeks).
- Stillbirth: Large haematomas may increase the risk of stillbirth, though this is rare.
- Placental abruption: The haematoma may cause the placenta to detach from the uterine wall, leading to serious complications.
- Preterm labour: Subchorionic bleeding is associated with an increased risk of preterm delivery.
- Preterm premature rupture of membranes: The membranes surrounding the baby may rupture early, leading to premature labour.
- Foetal growth restriction: In some cases, particularly with IVF pregnancies, subchorionic haematomas may be linked to lower birth weight in singleton pregnancies.
- Preeclampsia: There could be a link between subchorionic haematomas and this serious condition.
Impact of Subchorionic Bleeding in Twin Pregnancies
In twin pregnancies, the impact of subchorionic bleeding may differ from that in singleton pregnancies. A study titled ‘Subchorionic Hematomas and Adverse Pregnancy Outcomes among Twin Pregnancies’ involving 760 twin pregnancies found that a first-trimester subchorionic haematoma was not significantly associated with adverse outcomes such as preterm birth, low birth weight, foetal demise, or preeclampsia. This suggests that the presence of a haematoma in twin pregnancies may not carry the same level of risk as in singleton pregnanciesDiagnosis of Subchorionic Bleeding
Subchorionic bleeding is most commonly diagnosed through ultrasonography, which is the preferred imaging modality. Colour Doppler ultrasound can differentiate between an avascular haematoma and a vascular placenta by detecting blood flow. While the placenta exhibits blood flow, the haematoma does not.The sensitivity of ultrasound for detecting subchorionic haematomas is relatively low. Follow-up ultrasounds may be recommended to monitor the haematoma’s size and ensure the baby is healthy.However, magnetic resonance imaging (MRI) can sometimes identify haematomas and help determine their age based on blood product signals.Treatment and Management of Subchorionic Bleeding
Many subchorionic haematomas resolve on their own, particularly if they are small or moderate in size. Your healthcare professional will assess the haematoma’s size, location, and your symptoms to determine the best course of action. Possible management strategies include:- You may be recommended to reduce physical activity, such as avoiding exercise or heavy lifting.
- In some cases, complete bed rest may be advised.
- Avoiding sexual intercourse can help prevent further irritation or bleeding.
- Regular ultrasounds may be scheduled to monitor the haematoma’s size and the baby’s growth.
- Monitoring for early labour signs. Your doctor may educate you on symptoms like contractions or cramping.
- Severe bleeding after 24 weeks or signs of preterm labour may require hospital admission.
- If you are RhD-negative and your baby is Rh-positive, Anti-D immune globulin (RhoGAM) medication may be administered to prevent complications.
Does a Subchorionic Haematoma Make a Pregnancy High-Risk?
Whether a subchorionic haematoma classifies a pregnancy as high-risk depends on the severity of the haematoma and the presence of other medical conditions. If the haematoma is large or causes excessive bleeding, it is likely to be considered high-risk.If the haematoma is small and only results in minor spotting, it may not elevate the pregnancy to high-risk status. In such situations, your healthcare professional may recommend a follow-up ultrasound in a few weeks to monitor its progress.Subchorionic bleeding can be scary, but it often resolves on its own. Early diagnosis and regular follow-up can help protect your pregnancy. Talk to your healthcare professional if you notice bleeding or other unusual symptoms. With the right care, many people go on to have healthy pregnancies even after a haematoma is detected.FAQs on Subchorionic Bleeding in Pregnancy: Symptoms, Complications, and Management
- What causes subchorionic bleeding?It happens when the chorionic membrane partially pulls away from the uterus, often due to uterine abnormalities, infections, trauma, or IVF treatment.
- What are the symptoms of subchorionic bleeding?The most common symptom is vaginal bleeding. Some people may also have pelvic cramping or no symptoms at all.
- Is subchorionic bleeding dangerous during pregnancy?It can be dangerous if the haematoma is large or causes heavy bleeding. But in many cases, it resolves on its own without harming the baby.