Blood loss during delivery of placenta

Following delivery, we expect women to experience a fair amount of bleeding. In fact, women typically bleed up to a half-quart of blood following a normal delivery and up to a quart of blood after a cesarean section (C-section). However, about 3 to 5 percent of new moms experience excessive blood loss, or postpartum hemorrhage.

While that percentage is relatively small as it pertains to overall deliveries, postpartum hemorrhage remains a common complication that can occur during delivery; in fact, we see women with this condition on a weekly basis. Because that’s so, we want to make sure women understand the common causes, why they might be considered at higher risk, and potential treatment options.

What causes postpartum hemorrhage?

About 70 to 80 percent of the postpartum hemorrhage cases we see are the result of the woman’s uterus not contracting after delivery, a condition called uterine atony. In a normal delivery, the uterus contracts substantially once the placenta is removed, which prevents bleeding from blood vessels that previously supplied blood to the placenta.

Other postpartum hemorrhage risk factors include:

● Genital tract lacerations: Tissue damage or trauma of the lower genital tract that occurs during the birth process

● Retained placental fragments: Retention of the placenta or fetal membranes within the uterus following delivery

● Clotting defects: Delayed formation of blood clots after delivery occurs

The majority of women who experience a postpartum hemorrhage have at least one risk factor for postpartum hemorrhage. However, 40 percent of women will not have any identifiable risk factors. The most common risks we do see are:

● Abnormalities of the labor process, such as prolonged labor or need for labor induction

● A uterus that is overdistended from a large baby, a twin or triplet pregnancy or from excess levels of amniotic fluid

● A first-time childbirth or history of many prior children

Related reading: The ‘fourth trimester’: Why women need health care after delivery

What is postpartum hemorrhage?

Postpartum hemorrhage is more bleeding than normal after the birth of a baby. About 1 in 100 to 5 in 100 women have postpartum hemorrhage. It's more likely with a cesarean birth. It most often happens after the placenta is delivered, but it can also happen later.

What causes postpartum hemorrhage?

Once a baby is delivered, the uterus normally contracts and pushes out the placenta. After the placenta is delivered, these contractions help put pressure on the bleeding vessels in the area where the placenta was attached. If the uterus does not contract strongly enough, these blood vessels bleed freely. This is the most common cause of postpartum hemorrhage. If small pieces of the placenta stay attached, bleeding is also likely. 

Postpartum hemorrhage may also be caused by:

• Tear in the cervix or tissues of the vagina

• Tear in a blood vessel in the uterus

• Bleeding into a hidden tissue area or space in the pelvis. This mass of blood is called a hematoma. It's usually in the vulva or vagina.

• Blood clotting disorders

• Placenta problems

Who is at risk for postpartum hemorrhage?

Some women are at greater risk for postpartum hemorrhage than others. Conditions that may increase the risk include:

• Placental abruption. This is the early detachment of the placenta from the uterus.

• Placenta previa. This is when the placenta covers or is near the opening of the cervix.

• Overdistended uterus. This is when the uterus is larger than normal because of too much amniotic fluid or a large baby.

• Multiple-baby pregnancy

• High blood pressure disorders of pregnancy

• Having many previous births

• Prolonged labor

• Infection

• Obesity

• Use of forceps or vacuum-assisted delivery

• Being of Asian or Hispanic ethnic background

What are the symptoms of postpartum hemorrhage?

These are the most common symptoms of postpartum hemorrhage:

• Uncontrolled bleeding

• Decreased blood pressure

• Increased heart rate

• Decrease in the red blood cell count

• Swelling and pain in the vagina and nearby area if bleeding is from a hematoma 

The symptoms of postpartum hemorrhage may look like other health conditions. Always see your healthcare provider for a diagnosis.

How is postpartum hemorrhage diagnosed?

Your healthcare provider will review your health history and do a physical exam. Lab tests often help with the diagnosis. Other tests may include:

• Estimate of how much blood you have lost

• Measuring pulse and blood pressure

• Red blood cell count

• Clotting factors in the blood

How is postpartum hemorrhage treated?

The aim of treatment of postpartum hemorrhage is to find and stop the cause of the bleeding as soon as possible. Treatment may include:

• Medicine or uterine massage to stimulate uterine contractions

• Removing pieces of the placenta that remain in the uterus

• Exam of the uterus and other pelvic tissues, the vagina, and the vulva to look for areas that may need repair

• Bakri balloon or a Foley catheter to put pressure on the bleeding inside the uterus. Your healthcare provider may pack the uterus with sponges and sterile materials. This may be done if a Bakri balloon or Foley catheter is not available. 

• Laparotomy. This is surgery to open the abdomen to find the cause of bleeding.

• Tying off or sealing bleeding blood vessels. This is done using uterine compression sutures, special gel, glue, or coils. The surgery is done during a laparotomy.

• Hysterectomy. This is surgery to remove the uterus. In most cases, this is a last resort.

Replacing lost blood and fluids is important in treating postpartum hemorrhage. You may quickly be given IV (intravenous) fluids, blood, and blood products to prevent shock. Oxygen may also help.

Postpartum hemorrhage can be quite serious. But when your provider quickly finds and treats the cause of bleeding, you often will be able to recover fully.

What are possible complications of postpartum hemorrhage?

Losing lots of blood quickly can cause a severe drop in your blood pressure. This may lead to shock and death if not treated.

What can I do to prevent postpartum hemorrhage?

It’s important to know before delivery what puts you at risk for postpartum hemorrhage. It's important to have emergency care available in case it is needed at the time of delivery and after birth. Early care can reduce the amount of blood loss.

When should I call my healthcare provider?

Most cases of postpartum hemorrhage occur at delivery or soon after. But you may bleed heavily after you go home from the hospital. Talk with your healthcare provider about the symptoms of postpartum hemorrhage and what to watch for. During your hospital stay or once you get home, call your healthcare provider right away if you have any of the following:

• Vaginal bleeding that needs a new sanitary pad after an hour, or you pass large blood clots

• Feeling lightheaded, dizzy, or you faint

• Belly pain that is new or gets worse

• Extreme tiredness (fatigue)

• Fast heartbeat or pulse

• Blurry vision

Key points about postpartum hemorrhage

• Postpartum hemorrhage is heavy bleeding after the birth of your baby.

• Losing lots of blood quickly can cause a severe drop in your blood pressure. It may lead to shock and death if not treated.

• The most common cause of postpartum hemorrhage is when the uterus does not contract enough after delivery.

• Quickly finding and treating the cause of bleeding can often lead to a full recovery.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.

How much blood loss is normal during delivery?

What causes blood loss during delivery?

What happens if you lose too much blood during labor?

What are the 4 most common causes of postpartum hemorrhage?