The Lifeline of Pregnancy: Understanding the Vital Functions of the Placenta

When you think about it, pregnancy is amazing; it’s a miracle how your body was formed in order to support the life that’s growing inside you. And in this process, there’s an organ that is vital in making sure your baby gets the nutrients he needs to survive from beginning to end – the placenta.

This article is all about the placenta: its role in pregnancy and when you should be concerned that not all is well with this life-giving organ, warranting medical attention.

What Is the Placenta?

The placenta is an organ specially grown in your uterus during pregnancy to support your developing baby. It is the starting point of your baby’s umbilical cord, and it grows as your baby grows and as the number of amniotic fluid increases.

It is made up of the same cells as your baby and attaches itself to the wall of your uterus, usually at the top or side.

When does the placenta form in pregnancy?

According to Cleveland Clinic, the placenta starts to form after a fertilised egg implants in your uterus around seven to 10 days after conception. It starts as a few cells and grows to several inches as your pregnancy progresses.

What does the placenta look like?

In terms of appearance, it is usually flat and circular in shape, which is why it’s usually likened to a pancake.  Its size can vary, but on average, it measures about 6 to 8 inches in diameter and around 1 inch thick. It’s colour can range from reddish-brown to dark maroon, depending on the stage of pregnancy and blood flow.

The outer surface of the placenta, known as the maternal side, is generally smooth and shiny. On the inner side, called the foetal side, numerous branching blood vessels can be seen, giving it a more textured appearance.

When does the placenta take over?

After the first trimester, around weeks 8 to 12, the placenta takes over key functions such as hormone production and providing nutrients to your baby. Around this time, pregnancy symptoms such as nausea and morning sickness also diminish.

However, in this context, “taking over” means that what you consume can now reach your baby via the umbilical cord and placenta. Your own hormone production and nutrition are vital during this stage.

After your baby is born, your placenta — which by now is around the size of a dinner plate — is also delivered. Some women opt to consume it in the form of specially-made pills This is known as placental encapsulation. 

How is the Placenta Delivered

The process of delivering the placenta is called the third stage of labour. It typically occurs within 5 to 30 minutes after the baby is born.

It separates from the uterine wall, and the mother experiences contractions to help expel it from her body. These contractions may feel similar to the earlier labour contractions, but they are usually milder.

Once the placenta is fully detached, the mother may be instructed by healthcare professionals to push or gently assist in its delivery. In some cases, a healthcare provider may need to manually remove the placenta if it does not come out naturally.

After the placenta is delivered, the mother may experience ongoing contractions as the uterus continues to contract and shrink.

Some women choose to consume their placenta for health benefits, via a process known as placenta encapsulation.

Role of the Placenta

Your growing baby gets all the oxygen and nutrients he needs via the placenta, throughout the duration of your pregnancy.

This happens because the placenta links your blood supply with your baby’s, transferring everything he needs to grow and develop, directly to him.

In fact, experts point out that during every minute of pregnancy, “around 550 millilitres of blood is pumped into the uterus to exchange enough nutrients with the placenta for your baby.”

This is also why pregnant mums need to be careful about what they eat and drink during pregnancy, as well as the drugs they take, as these pass directly to their growing babies.

This incredible organ also produces hormones that help to trigger labour. But until the time is right for your baby’s birth, the placenta secretes hormones such as progesterone and estrogen to prevent early labour.

It also removes waste products from your baby’s blood to yours, which your body disposes of. At the same time, it keeps your baby’s and your blood separate, almost acting like a filter, which helps to protect your baby from infections and harmful substances.

According to the UK’s National Health Service (NHS), towards the end of your pregnancy, “the placenta passes antibodies from you to your baby, giving them immunity for about three months after birth.”

The placenta also works almost like padding to cushion your baby while within your womb and provides your little one with the perfect, unique environment to thrive and grow.

How Does the Placenta Work in Twins

In twin pregnancies, the placenta plays a vital role in supporting the growth and development of both fetuses. The placenta’s functioning in twin pregnancies depends on the type of twins: whether they are identical (monozygotic) or fraternal (dizygotic).

In identical twin pregnancies, where a single fertilised egg splits into two embryos, the placenta can take different forms. It can be a monochorionic monoamniotic (MCMA) placenta, where both twins share one placenta and one amniotic sac, or a monochorionic diamniotic (MCDA) placenta, where both twins share one placenta but have separate amniotic sacs.

In either case, the placenta distributes nutrients and oxygen to both fetuses and removes waste products from their bloodstreams.

In fraternal twin pregnancies, where two separate eggs are fertilised by two different sperm, each fetus typically has its own individual placenta and amniotic sac. Each placenta functions independently, supplying the necessary nutrients and oxygen to its respective fetus.

The placenta in twin pregnancies adapts to accommodate the needs of multiple fetuses, and its size and structure can vary. It is important for healthcare providers to monitor the development and functioning of the placenta throughout the pregnancy to ensure the well-being of both twins.

Factors Affecting Placental Health

There are various factors that affect the health of your placenta, according to the medical experts at Mayo Clinic. While there’s nothing much you can do to change some of these, other factors are modifiable.

• Maternal age: Pregnant women over the age of 40 are at a higher risk of placental problems.
• High blood pressure: Hypertension during pregnancy can have a negative effect
• Premature rupture of the membranes: If your baby’s amniotic sac (a fluid-filled membrane surrounding him or her) leaks or ruptures prematurely during pregnancy
• Substance abuse: Women who smoke or use drugs such as cocaine during pregnancy are at a higher risk of experiencing placental problems.
• Multiple pregnancies: Carrying twins or triplets (or more) may increase the likelihood of the mother experiencing issues.
• Abdominal trauma: Some placental problems may arise if a pregnant mum suffers a blow to her stomach or other similar trauma.
• Blood-clotting disorders: If you have a medical condition that affects your blood’s clotting ability, you may be at a higher risk of suffering from placental health problems.

Smoking and taking illicit drugs during pregnancy can sharply increase the risk of placental health problems.

Common Placental Problems

Most of the time and in most pregnancies, the placenta functions just fine. But sometimes, placental problems can crop up, particularly in advanced pregnancy.

The following are the most commonly encountered medical issues:

1. Placenta Previa

What it is: This condition occurs as a result of the placenta partially or completely covering the cervix which is the womb’s opening. It usually is experienced in early pregnancy and sometimes corrects itself as the uterus grows.

Risk factors: Smoking and drug use, getting pregnant after 35, being pregnant with multiples.

Health risks: Placenta previa can cause severe bleeding during or after a baby’s birth, endangering the lives of both mum and baby. The birth process may be disrupted too since the cervix is fully or partially covered.

Signs and symptoms: Sometimes there are no symptoms at all and the condition might be picked up by routine ultrasound. Other times, placenta previa is marked by painless vaginal bleeding.

Treatment: If placenta previa is experienced in the first half of the pregnancy, it usually corrects itself. However, you will still be monitored carefully by your doctor for the duration of your pregnancy. If the condition is still present in the second half of your pregnancy, it is highly likely that your doctor will recommend a C-section to deliver your baby.

Placenta previa can occur partially or fully

2. Placental Abruption

What it is: Here, the placenta peels away (partially or fully) from the womb’s inner wall, usually close to delivery, but sometimes as early as 20 weeks of pregnancy.

Risk factors: Trauma to the abdomen, being older than 35, being pregnant with multiples, not having enough amniotic fluid, water breaking too early, uncontrolled high blood pressure, smoking and using drugs (e.g. cocaine).

Health risks: The baby can be starved of oxygen and nutrition, and the mum can experience bleeding and cramps. Placental abruption may also trigger premature birth.

Signs and symptoms: Continuous or sudden stomach pain, bleeding from the vagina sometimes with discomfort and tenderness of the uterus.

Treatment: If you are close to being full term and you have mild placental disruption, your doctor may suggest immediate delivery of your baby, either via induced labour or C-section. If you are diagnosed with this condition early on in your pregnancy, you will probably be monitored closely by your healthcare provider.

3. Placenta accreta

What it is: Medical experts explain that placenta accreta is a result of placental blood vessels growing too deeply into the wall of the uterus. Also, “more-aggressive forms of this problem can also occur if the placenta invades the muscles of the uterus (placenta increta) or if the placenta grows through the uterine wall (placenta percreta).”

Risk factors: Previous uterine surgery or have had placenta previa.

Health risks: Severe bleeding following vaginal birth or premature birth.

Signs and symptoms: Heavy vaginal bleeding in the third trimester.

Treatment: C-section delivery followed by surgical removal of the uterus (abdominal hysterectomy). More aggressive forms of this problem can also occur if it invades the muscles of the uterus (increta) or if the placenta grows through the uterine wall (percreta).

4. Retained placenta

What it is: Sometimes, the placenta gets trapped in the uterus after the birth of your baby, because of a partially closed cervix, or because it is still attached to the uterine wall.

Health risks: Heavy bleeding (postpartum haemorrhage) that may affect the health of the mother if not stopped.

Signs and symptoms: No delivery 30 to 60 minutes after the birth of your baby.

Treatment: If you have not delivered your placenta within 30 to 60 minutes after the birth of your baby, your healthcare providers may give you an injection of syntometrine or syntocinon to make your uterus contract strongly, thus expelling it. In some cases, doctors may manually remove it (following numbing of the area).

How to Reduce the Risk of Placental Problems

To promote a healthy placenta and reduce the risk of complications, consider implementing these strategies:

• Maintain a healthy lifestyle

Adopting a healthy lifestyle is key to reducing the risk of placental problems. This includes eating a nutritious diet, staying physically active with doctor-approved exercises, avoiding smoking and substance abuse, and managing stress levels effectively. Also, make sure to practice caution and buckle up every time you’re travelling.

• Attend regular prenatal check-ups

Attending regular prenatal check-ups is essential for monitoring the health of both the mother and the placenta. These appointments allow healthcare professionals to detect any potential issues early on and take appropriate measures to address them promptly.

• Control chronic health conditions

If you have any chronic health conditions such as diabetes, high blood pressure, or autoimmune disorders, it’s important to work closely with your healthcare provider to manage these conditions effectively. Proper control of chronic health conditions can help minimise the risk of placental problems.

• Avoid certain medications and environmental hazards

Certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), and exposure to environmental hazards, such as toxic chemicals or heavy metals, may pose a risk to the placenta. Consult with your healthcare provider to ensure the safety of any medications and to minimise exposure to potential hazards.

• Monitor fetal movement

Monitoring your baby’s movements regularly can provide valuable insights into the well-being of the placenta. Be aware of your baby’s regular patterns of movement and contact your healthcare provider if you notice a decrease in activity or any concerning changes.

Remember, each pregnancy is unique, and it’s important to consult with your healthcare provider for personalised advice and guidance.

Placenta Problems: When to Seek Help

Mums, while it’s unlikely that you will experience any problems with your placenta in your pregnancy, do consult your doctor without delay if you experience:

• Vaginal bleeding
• Trauma to your abdomen
• Strong uterine contractions
• Severe back pain

Also, make sure you visit your healthcare provider regularly throughout your pregnancy — the earlier placental issues are diagnosed, the better the chance is of reducing complications both for you and your baby.

Image Source: iStock

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