How Common is Third Trimester Miscarriage? Causes, Risks, and Prevention

The journey of pregnancy is a deeply personal experience, filled with excitement, anticipation, and sometimes, fear. Unfortunately, some individuals experience miscarriages during pregnancy, which can be emotionally and physically overwhelming. While most miscarriages occur in the early stages, the occurrence of third trimester miscarriage — typically defined as a loss that occurs after 20 weeks of gestation — is a rare but deeply traumatic experience for expectant parents. Understanding the causes, risks, and management strategies for this type of miscarriage can help individuals navigate this difficult experience.

In this article, we will explore the likelihood of third trimester miscarriage, its causes, the importance of antenatal care, and the available support options for parents dealing with such a loss. We will also look at preventive measures, the role of antenatal support, and how antenatal education and prenatal care can reduce risks and help parents prepare for a healthy pregnancy.

The Rarity of Third Trimester Miscarriage

When most people think about miscarriage, they often associate it with early pregnancy loss, typically occurring within the first 12 weeks. However, third trimester miscarriage — which refers to the loss of a pregnancy after 20 weeks — is significantly rarer. Studies show that third trimester miscarriage accounts for only about 1% of all miscarriages, making it a relatively uncommon event.

According to the Royal College of Obstetricians and Gynaecologists (RCOG), the overall rate of stillbirth in the UK is approximately 1 in 250 pregnancies. While not all third trimester losses are classified as stillbirths, many involve complications in the later stages of pregnancy that result in the loss of the baby. It is crucial to distinguish between stillbirth (the death of a fetus after 20 weeks but before or during delivery) and miscarriage, which can also occur after 20 weeks but often involves other contributing factors.

Types of Third Trimester Miscarriage

Stillbirth: A stillbirth refers to the loss of a baby after the 20th week of pregnancy but before or during delivery. It can happen for various reasons, including complications in the placenta, infections, or issues related to maternal health.

Premature Birth and Loss: Sometimes, a pregnancy may advance into the third trimester, but premature birth, often induced due to medical complications or concerns for the mother’s health, can lead to the loss of the baby. This could happen if the baby is too premature to survive outside the womb.

While the risk of third trimester miscarriage is relatively low, the emotional and psychological toll it takes on the family cannot be understated. Understanding the causes of such a loss and being aware of the support systems available during pregnancy can help alleviate anxiety and enable individuals to seek early interventions and antenatal care if needed.

What Causes Third Trimester Miscarriage?

Understanding the factors that contribute to third trimester miscarriage can help expectant parents manage their pregnancy with increased awareness and proactive care. The reasons for a third trimester miscarriage can vary significantly, ranging from complications during pregnancy to health conditions that affect the mother or baby.

1. Placental Problems

The placenta plays a vital role in supplying oxygen and nutrients to the baby throughout pregnancy. Placental insufficiency occurs when the placenta fails to deliver adequate nutrients and oxygen, which can cause the baby to stop developing and result in miscarriage or stillbirth. Conditions such as placental abruption, where the placenta detaches prematurely from the uterine wall, are common causes of third trimester losses.

2. Infections

Certain infections during the later stages of pregnancy, such as bacterial infections, sepsis, or listeriosis, can lead to a miscarriage or stillbirth. These infections can severely affect the baby’s health, leading to complications like preterm birth, intrauterine growth restriction, or fetal death.

3. Maternal Health Issues

Underlying health conditions in the mother can increase the risk of miscarriage in the third trimester. High blood pressure, diabetes, pre-eclampsia, and autoimmune disorders such as lupus can all contribute to complications that affect the pregnancy. When these conditions are poorly managed, they can lead to a higher risk of stillbirth.

4. Genetic and Chromosomal Abnormalities

While most genetic or chromosomal abnormalities are detected early in pregnancy, some may not become apparent until the later stages. These abnormalities can lead to developmental issues or the inability of the fetus to survive in utero.

5. Trauma or Physical Injury

Physical trauma, such as a severe fall or car accident, can sometimes cause miscarriage in the third trimester. However, this is relatively rare, as the body’s natural protection mechanisms often protect the fetus until the later stages of pregnancy.

6. Multiple Pregnancies

Pregnancies involving twins or higher-order multiples are at an increased risk for complications, including third trimester miscarriage. The added strain on the uterus and placental insufficiency can lead to complications in the later stages of pregnancy.

Importance of Antenatal Care and Monitoring

Regular antenatal care plays a significant role in identifying potential risks and preventing complications during pregnancy. Prenatal care helps healthcare professionals monitor both the baby’s development and the mother’s health, which can be crucial for early detection of conditions that may increase the risk of miscarriage or stillbirth.

1. Antenatal Appointments

Regular antenatal appointments help track the growth and development of the baby and monitor any changes in the mother’s health. Routine antenatal scans, such as ultrasound examinations, can detect abnormalities in the placenta or signs of growth restriction that may increase the risk of complications in the third trimester. It is essential for expectant mothers to attend these appointments and address any concerns with their healthcare provider.

2. Blood Pressure and Blood Sugar Monitoring

Conditions like high blood pressure, pre-eclampsia, or gestational diabetes can all lead to an increased risk of third trimester miscarriage. Regular monitoring of blood pressure and blood glucose levels is essential to ensure that any problems are detected and managed early. Healthcare providers may suggest changes in diet, lifestyle, or medication to help manage these conditions.

3. Prenatal Vitamins and Supplements

Taking antenatal vitamins is crucial for a healthy pregnancy, particularly for ensuring that the mother gets the necessary nutrients for the baby’s development. Certain deficiencies, such as a lack of folic acid or iron, can increase the risk of complications. Following a healthcare provider’s recommendations regarding supplementation is essential for managing a healthy pregnancy.

Coping with Anxiety About Third Trimester Miscarriage

While third trimester miscarriage is rare, it is natural for expectant parents to feel anxiety about the possibility of losing a baby in the later stages of pregnancy. Anxiety during pregnancy is common, particularly if you have experienced loss before or have risk factors.

Here are some strategies for managing anxiety during pregnancy:

1. Antenatal Support

Having a support system in place is crucial for managing the emotional challenges of pregnancy. Antenatal support can come from a variety of sources, including your partner, friends, family, and healthcare providers. Your healthcare provider can offer reassurance and help you navigate any concerns or fears you may have during your pregnancy.

2. Prenatal Yoga and Relaxation

Participating in pregnancy yoga classes can help reduce anxiety and improve mental well-being. Antenatal yoga is designed to reduce stress, promote relaxation, and strengthen the body for labour. It can also help relieve physical discomfort associated with pregnancy, such as back pain or swelling.

3. Counselling or Therapy

If you find yourself feeling overwhelmed with fear or anxiety, consider speaking to a therapist or counsellor. Pregnancy-related anxiety is common, and professional support can help you manage these feelings and work through your emotions. Therapy can also help if you have experienced previous pregnancy losses and are struggling to cope with the possibility of another loss.

Preventing Third Trimester Miscarriage

While not all third trimester miscarriages can be prevented, there are measures expectant parents can take to minimise risk and promote a healthy pregnancy:

Regular Prenatal Care: Attending all antenatal checkups and staying on top of any recommended tests or screenings is one of the most important steps you can take to prevent complications. Your healthcare provider will provide guidance on maintaining a healthy pregnancy.

Managing Chronic Health Conditions: Properly managing conditions like high blood pressure or diabetes can significantly reduce the risk of complications during pregnancy.

Avoiding Harmful Substances: Avoid smoking, drinking alcohol, or using drugs during pregnancy. These substances can increase the risk of third trimester complications.

Conclusion: Third Trimester Miscarriage and the Importance of Antenatal Care

Although third trimester miscarriage is a rare and heartbreaking experience, understanding the potential causes and risks can help expectant parents manage their anxiety and ensure a safer pregnancy. Regular antenatal care, proper management of underlying health conditions, and antenatal support are essential in reducing the risk of complications and preparing for the birth of a healthy baby.

Remember, if you have any concerns or fears during your pregnancy, it’s always important to seek support from your healthcare provider. They are there to help guide you through your pregnancy and provide reassurance every step of the way.