Bleeding in second and third trimesters in pregnancy and what to do

Published 13th April 2021 | Dr Ujwala Parashar

Congratulations – your pregnant! Pregnancy is a time of great joy, but you may also find yourself worried if you experience bleeding. Vaginal bleeding in pregnancy has many causes, some of which are serious, and some are not.

Bleeding in early pregnancy is quite common with around 15-25% of pregnant women experiencing bleeding in the first trimester. However, bleeding in middle to late pregnancy (the second and third trimester) is less common and may be an indication of a serious problem.

What is the difference between spotting and bleeding?

Spotting is when you notice a few drops of blood every now and then. It is not frequent and not enough to cover a panty liner.

Bleeding is a heavier blood flow. If you are bleeding, you will need a pad or liner to prevent blood from soaking your clothes.

What causes bleeding during middle to late pregnancy? What are the symptoms and treatments?

There are numerous causes of bleeding during middle to late pregnancy, some are not serious and can be from mild inflammation, benign cervical polyps, intercourse, or because of a pelvic examination. This will generally only result in mild spotting that stops within a day or two.

However, heavier, and persistent bleeding is more serious than light bleeding or spotting. Causes for heavier bleeding may be from conditions relating to problems with the cervix or the placenta. Some of the more common serious conditions that can cause vaginal bleeding in middle to late pregnancy, symptoms and treatment include:


Also known as weakened cervix or a cervical insufficiency. Before pregnancy, a normal cervix (the lower part of the uterus that opens to the vagina) is closed and firm. When you become pregnant and your body prepares itself for birth, your cervix changes; becoming softer and shorter, and opens (dilates). An incompetent cervix can open too early causing premature birth or loss of an early pregnancy.

An incompetent cervix occurs in approximately 1-2% of pregnant women and accounts for almost 25% of miscarriages in the second trimester. It can be difficult to diagnose and treat and your obstetrician taking a full medical history that highlights previous cervical insufficiency is important for early intervention and treatment.

Signs and symptoms of an incompetent cervix

Most women will not have symptoms during early pregnancy of an incompetent cervix. In some cases, women experience mild discomfort or some blood spotting starting between weeks 14 – 20. Other signs can include:

·      A sensation of pelvic pressure

·      A new backache

·      Changes in vaginal discharge

·      Cramps in the abdomen

·      Braxton-Hicks

What is the treatment for an incompetent cervix?

In some instances, progesterone supplementation is recommended, but the most common treatment for an incompetent cervix is a minor interventional procedure called a “cerclage” where a few stitches are sewn around the weakened cervix as reinforcement. A cerclage is usually performed between week 12 – 14 of pregnancy.


This is when the placenta detaches from the uterus wall. Once detached (either partially or totally) it cannot be reattached.  Placental abruption can result in the mother bleeding, but it may also interfere with the unborn baby’s oxygen and nutrient supply. 

About 1 in 100 pregnant women experience placental abruption worldwide.

·      Around 50% of cases are mild or in early pregnancy and are manageable through close monitoring

·      Around 25% of cases are moderate

·      The remaining 25% are severe and can threaten the life of the mother and the baby

A placental abruption requires immediate medical attention.

Signs and symptoms of moderate to severe placental abruption

·      Vaginal bleeding

·      Abdominal pain (continual)

·      Lower back pain (continual)

·      Painful abdomen (belly) when touched

·      Tender and hard uterus

·      Very frequent contractions

What are some of the risk factors for placental abruption?

In most instances the cause is unknown but there are certain factors that may increase the risk of placental abruption. These can include:

·      Older maternal age

·      Prior pregnancy – the risk increases with each pregnancy

·      Twins or other multiple pregnancy

·      Prior history of placental abruption

·      Mother has high blood pressure

·      An excess of amniotic fluid

·      Lifestyle risk factors (smoking, alcohol, illicit drug use)

Can placental abruption be prevented?

It can’t be prevented, but you can decrease the risk factors by taking folic acid, controlling your blood pressure, and not smoking, drinking alcohol, or using illicit drugs.

What is the treatment for placental abruption?

Once placental abruption is suspected or diagnosed, close monitoring is required. This is usually done in hospital and will include regular checks of the mother and baby’s vital signs. Treatments vary depending upon the severity and can include:

·      Mild cases in early pregnancy. If the bleeding stops and the baby isn’t distressed you will be allowed to go home and rest but will need regular check-ups and monitoring to ensure your condition has not worsened.

·      Moderate cases in early pregnancy. You may be required to remain in hospital until it is safe for an induced labour.

·      Mild to moderate cases in later pregnancy. If placental abruption occurs at 36 weeks or more, delivery may be recommended. In some instances, vaginal birth may still be possible however, a caesarean section may be necessary.

·      Severe cases require immediate delivery.


Placenta previa occurs in middle to late pregnancy – from around 20 weeks and is when the placenta is sitting very low in the uterus and partially or fully covers the cervix resulting in bleeding. There are three types of placenta previa: total, marginal, partial. 

It occurs in about 1 in 200 pregnancies and usually is not a problem in early pregnancy, but can cause serious bleeding and complications later in pregnancy.

Causes and symptoms of placenta previa

The most common symptom is bright red and painless blood from the vagina. Although it is unknown what causes placenta previa, it is believed to be more likely to occur in women who have had the following conditions or for lifestyle reasons.  

·      Past pregnancy

·      Uterine fibroids

·      Previous uterine surgery

·      Previous caesarean delivery

·      Previous history of placenta previa

·      Older maternal age

·      Certain non-anglo ethnicity

·      Smoking

·      Being pregnant with a boy

How is placenta previa diagnosed and treated?

Your medical history, a physical exam and an ultrasound are used to diagnose placenta previa. There is no treatment for placenta previa, but it is managed by:

·      Regular ultrasounds to track the placenta

·      Bed rest at home, or in hospital (depending upon the severity)

·      Early delivery (depending upon conditions such as how much bleeding, how many weeks pregnant you are, the health of the baby)

·      Caesarean delivery

·      Blood transfusions in the case of severe blood loss


Miscarriage is the loss of a baby before 20 weeks of pregnancy. 1 in 5 known pregnancies end in miscarriage. In many instances, miscarriage is outside of your control and due to the baby not developing properly; often from a spontaneous chromosomal abnormality. 

Although very upsetting, most women who experience a miscarriage will have a healthy pregnancy in the future.

Signs, symptoms and causes of miscarriage

Apart from vaginal bleeding, the most common sign of miscarriage is cramping pains in the tummy that feels like menstrual pain. Causes include:

·      Hormonal abnormalities

·      Immune and blood clotting problems

·      Medical history of thyroid conditions and diabetes

·      Infections that cause high fevers (not common colds)

·      Structural problems with the womb or cervix

Are there risk factors for miscarriage?

Women have a greater risk of miscarriage if they:

·      Older maternal age

·      Are smokers

·      Drink alcohol in the first trimester

·      Consume too much caffeine

·      Have had a previous miscarriage

Positive steps for the possible prevention of miscarriage include:

Maintaining a healthy lifestyle with no smoking, alcohol, caffeine, illicit drugs. Unfortunately, is important to note that a miscarriage cannot be prevented once it has begun.


Vaginal bleeding after 37 weeks and before 40 weeks can indicate that your body is getting ready to delivery and can mean preterm labour. Preterm labour doesn’t always result in preterm birth – for approximately 3 in 10 women preterm labour stops on its own. 

What are the indications of preterm labour

Prior to going into labour, the mucus plug covering the uterus opening passes out of the vagina. It will look like an unusual discharge with a mixture of mucous and blood.  Other indications can include:

·      Mild abdominal cramps

·      Diarrhoea

·      Pelvic or lower abdominal pressure

·      Low, dull backache that is constant

·      Contractions

·      Your water breaks

If you have any signs of preterm labour, you should immediately contact your obstetrician.

What action to take if you experience bleeding in your second or third trimester

If you are experiencing bleeding (not light spotting) during your second or third trimester, you should take action to ensure your own well-being and that of your baby. 

In the first instance, our should call your GP or obstetrician to discuss your symptoms and ask what next steps are required to diagnose what might be causing your bleeding. 

Dr Parashar’s patients are provided with a 24/7 contact in the case of concerns with bleeding and pain. Our care team will be able to advise what action to take based on your symptoms and take all the necessary steps to ensure you receive the attention and treatment required to effectively manage your condition.

Dr Ujwala Parashar, Obstetrician & Gynaecologist

Sam Samant

Dr Ujwala Parashar is a highly trained female obstetrician and gynaecologist with over 15 years of professional experience and training, practicing in Sydney's North Shore and Barangaroo. If you would like more information on conception, or if you are seeking obstetric options and advice, please contact us or call 1300 811 827 to arrange a consultation with her.