The placenta is an oval-shaped, flat organ that connects your baby with your uterine wall.
Let’s begin with why our body even creates this.
But first, pregnancy is amazing!
In addition to growing a baby, your body develops an entirely new organ – the placenta!
This new organ supports your child and supplies them with oxygen and nutrients.
All the while removing waste products, your body grows a placenta.
When Does The Placenta Form?
The placenta implants into the wall of the uterus shortly after conception and the umbilical cord grows from it.
Usually, the placenta attaches to the top or top-side of the uterus.
What Does The Placenta Do?
The umbilical cord connects your placenta to your unborn baby and carries oxygen and nutrients to your baby while transferring waste products into your own bloodstream for disposal.
The placenta also produces hormones to help your baby grow and develop appropriately and protects your baby from bacteria that could cause an infection.
During the final weeks of pregnancy, the placenta passes antibodies to your baby from your blood.
This gives your baby the same immunity you have and lasts for a few months after birth.
How To Have A Healthy Placenta?
There are many factors that can affect the health of your placenta during pregnancy, some of which you have some control over and others which we can not accommodate for.
For example, some substances, such as alcohol, nicotine, and drugs pass through the placental membrane and can cause damage to your unborn baby.
Illicit drug use, such as cocaine use during pregnancy, increases the risk of placental problems.
Maternal age affects the health of the placenta, as some problems with the placenta are more common in women over the age of 40.
Sometimes, the amniotic sac membranes can rupture prior to delivery starting, which increases the risk of placental problems.
Other risks that increase the chance of placental problems include high blood pressure, multiple pregnancies (such as twins or triplets), and blood-clotting disorders.
Previous cesarean sections or other uterine surgery can increase the risk of placental problems, as can placental problems in a previous pregnancy.
Trauma to your abdomen while pregnant can also cause placental problems.
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Delivery of Placenta
After your baby is born, if all goes well the placenta detaches from the uterine wall. Contractions continue to push the placenta through the vagina to be delivered in the after-birth.
In some countries, women receive an injection to help stimulate the contractions to ensure the placenta is delivered.
The Third Stage of Labor:
Breastfeeding your baby as soon as you can after delivery helps your uterus contract and stimulates contractions to push the placenta out.
Your doctor, midwife or nurse will check the placenta to be sure it is intact and no remnants may remain in your uterus.
The most common types of placental problems include placental abruption (premature separation of the placenta from the wall of the uterus), placenta previa (placenta partially or completely blocks the neck of the uterus which interferes with normal delivery), placenta accreta, and retained placenta.
Each of these conditions can cause heavy bleeding from the vagina. Although it is normal to bleed some during the delivery of the afterbirth or placenta, heavy bleeding can be a sign of a complication.
If the placenta does not detach or does not detach completely, and parts remain in the uterus, severe complications can also result.
There are 3 main types of retained placenta:
- Placenta Adherens – where the muscles of the uterus fail to contract to push the placenta out.
- Partial Accreta – where the placenta attaches too deeply into the uterine wall to detach completely.
- Trapped Placenta – where the placenta detached but was trapped in the uterus by the closing cervix.
A retained placenta is a potentially life-threatening situation.
If the placenta is retained in the uterus, the blood flow is not cut off and blood may continue to flow. This can cause severe blood loss and may require a blood transfusion.
Retained placenta can cause severe infection and fertility problems down the road. Thankfully the incidence of retained placenta is low as healthcare partitioners are well trained for the signs and symptoms of retained placenta.
To remove a retained placenta, sometimes doctors perform “controlled cord traction“, where the umbilical cord is lightly pulled on to help the body expel the placenta. Sometimes the doctor may manually remove the placenta.
This may involve a doctor moving their hand inside the uterus and removing the placenta from the uterine wall before removing it through the vaginal opening.
Science has indicated the percentage of pregnancies affected by placenta accreta is increasing, possibly due to the rise in cesarean section deliveries.
According to research, 1 in 533 pregnancies for the period of 1982–2002 were affected by placenta accreta, increta or percreta. 
With a placenta accreta, the placenta attaches too deeply into the uterine wall but does not grow into the uterine muscle.
This accounts for about 75% of all placenta accreta, increta or percreta diagnoses.
Placenta increta occurs when the placenta attaches even deeper and penetrates the uterine muscles, and occurs about 15% of all placenta accreta, increta or percreta diagnoses.
Placenta percreta, the most serious, involves a placenta that has grown through the uterine wall and has attached to another organ. This is the least common type and accounts for less than 5% of all placenta accreta, increta or percreta cases.
Placenta accreta, increta or percreta usually require surgery to remove the placenta from the uterine wall.
Depending on how far the placenta attaches to the uterine wall, or if it pushes through the uterine wall, determines what treatment options are available. Sometimes, this may lead to a hysterectomy and total loss of the uterus.
Placenta accreta, increta or percreta is a high-risk pregnancy complication.
Chances are high it will disrupt your pregnancy and birth plans, and require pre-term delivery by c-section. Your safety and the safety of your baby is the top concern in deciding upon treatment options.
Placenta previa is a condition where the placenta partially or completely blocks the neck of the uterus, which in turn interferes with normal delivery.
Placenta previa is more common early in pregnancy and can resolve on its own as the uterus continues to grow and stretch.
This can cause heavy bleeding during the pregnancy and during delivery. If placenta previa is interfering with the delivery, a cesarean section may be ordered.
Placenta previa can be classified by the position of the placenta in relation to the cervix.
A complete (or total) placenta previa occurs when the placenta completely covers the cervical opening.
A partial placenta previa occurs when the placenta covers only part of the cervical opening while a marginal placenta previa occurs when only a small part of the placenta covers the cervical opening.
Watch this video below from, All Things Mama – My High-Risk Pregnancy: Placenta Previa
A low-lying placenta is not a type of placenta previa but occurs when the placenta implants in the lower part of the uterus but does not cover the cervical opening.
In the third trimester of pregnancy, about 1 in 200 pregnancies is affected by placenta previa, according to Stony Brook University Hospital in New York.
Placenta previa occurs more often in women with more than one child or a previous cesarean section.
If you were diagnosed with placenta previa early in your pregnancy (before 30 weeks) chances are high your uterus will continue to grow and the placenta previa will resolve.
Almost 90% of women diagnosed with placenta previa before 25 weeks will resolve by week 30 because the placenta moved up and away from the cervix.
Some practitioners won’t even mention a possible Previa before week 30 because of the high chance of resolution.
During the third trimester, placenta previa affects about 1 in 200 pregnant women.
Placenta previa is three times more likely to occur in women aged 30 and over, then those women under the age of 20.
Placenta previa occurs more often in women with:
- second or greater pregnancy
- previous cesarean section
- currently pregnant with multiples (twins, triplets, etc.)
- advanced maternal age (over age 35)
- abnormalities of the uterus
- scarring in the uterine lining
- smoking cigarettes during pregnancy
If you’ve been diagnosed with placenta previa during your third trimester, it might, unfortunately, require a change to your birth plans.
Thankfully, the chances are very high you will safely deliver a healthy baby!
Next, we’ll cover what you need to know about symptoms and when to get immediate treatment, so you and baby will be safe.
Placenta Previa Symptoms and Diagnosis
Placenta previa is usually diagnosed during an ultrasound in the third trimester.
Remember, placenta previas diagnosed before week thirty have a very high chance of resolving before birth.
Sometimes women experience symptoms before diagnosis:
- bright red vaginal bleeding (not spotting with can be normal), after week 20, but especially after week 33
- abdominal cramping, not unlike menstrual cramps
- breech baby, because the placenta is where the baby’s head should be, but can’t fit
Treatment of Placenta Previa
If you’ve been diagnosed with placenta previa during your third trimester, your practitioner may recommend:
- pelvic rest, which means no sex, no tampons, and no pelvic exams
- avoid strenuous activity, which means no running or lifting
- fetal monitoring to ensure your baby is safe and healthy
- bed rest or inpatient hospital stay
If you experience bright-red bleeding late in your pregnancy, contact your doctor or midwife immediately or call emergency services.
If you’ve been diagnosed with placenta previa, follow your practitioner’s advice.
Placenta previa is the most common cause of bleeding during later pregnancy.
Most bleeding can be treated before there is a risk to you or your baby, but severe hemorrhaging or bleeding can cause an emergency delivery. In extremely rare cases a blood transfusion may be required to treat severe blood loss.
If you are bleeding, chances are you will have to remain in the hospital for treatment.
Your baby may be delivered via cesarean section if you’re close to your due date.
C-sections are performed for about 80% of placental previas before labor starts. A cesarean section is required for complete placenta previa and usually required for partial placenta previa.
Rupturing the membranes can cause severe bleeding complications, so vaginal delivery is rarely attempted unless there is only a marginal risk of rupturing the placenta based on its location.
If your bleeding can be stopped or slowed considerably, you may be able to avoid early delivery, but you might have to stay for monitoring of you and your baby.
This includes being hooked up to a fetal heart monitor and having an amniocentesis to determine if the baby’s lungs are fully formed.
You may be given a steroid shot to help your baby’s lungs develop more quickly.
So again, what is the placenta?
An amazing little organ that can give life with a little risk to you!
image credit to – Healthline
1. Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005;192:1458–61. (PubMed) ↩︎