Preterm Labor | All You Need To Know

Having a baby has lots of excitement and a little anxiety. So the thought of going into preterm labor might send you into a tailspin.

You can never be fully ready for the arrival of your little one. Certainly reading some information about preterm birth now is much better than cramming later if it does happen.

Let’s discuss preterm labor, how it can happen, and what to do about it.

Preterm labor

What is defined as a full-term pregnancy can vary by up to five weeks. If you give birth between week 37 and week 42, this is considered full term.

A premature baby is born before 37 completed weeks of pregnancy. If you are 36 weeks and 6 days pregnant, your baby is still considered premature.

Once you reach 37 completed weeks, you’re considered early full term.

Remember, estimated due dates aren’t always completely accurate. If that’s the case, early full-term might actually be ‘premature’.

At the same time, you could actually be closer to 38 weeks. Babies born at this gestation usually don’t require assistance at the time of birth.

Premature labor and birth are divided into three subcategories:

• Mildly preterm (32-37 weeks)
• Moderately preterm (28-31 weeks)
• Extremely preterm (before 28 weeks)

To get a better idea of due dates and prematurity you might like to read Due Date Calculator – When Is My Baby Due? and Estimated Due Dates And The Myth Of The 40 Week Pregnancy.

What causes preterm labor?

Unfortunately, we don’t always know what causes preterm labor and premature birth. Sometimes, even if you do everything right during pregnancy, labor starts by itself without any triggers.

Although many organizations do lots of research into the causes, and screen for preterm labor, it’s very difficult to know how to prevent premature birth.

Preterm labor has several causes, but around 25% of preterm births happen for no known reason.

The most common reasons pregnant women have a preterm baby are:

• Premature rupture of membranes (30%)
• Bleeding during pregnancy (20%)
• Heart and blood pressure conditions (15%).

We know there are certain things that can increase the risk or chance of giving birth prematurely.

You might like to read Premature Labour – Signs, Symptoms and Management for more information.

Preterm labor risk factors

There are many risk factors that could cause preterm labor. A number of them have treatment options to decrease the risk; other risk factors can’t be treated or prevent preterm birth.

Some of the causes and high-risk factors for preterm labor include:

• Having had a previous preterm labor and birth
• Having twins or triplets, as generally, these babies will arrive early
• Having a short cervix, sometimes called an incompetent cervix.
• Chronic stress and anxiety, which can lead to problems that cause preterm birth
• Irritable uterus, which can be caused by outside factors like a UTI (urinary tract infection) or vaginal infections
• Recreational drugs, such as smoking, alcohol, and other illicit substances, which can lead to preterm labor and low birth weight.

Can dehydration cause preterm labor?

During pregnancy, a woman’s blood volume increases by up to 50%. This increase supports your body and baby. If you become dehydrated, your blood volume can decrease, which causes the levels of oxytocin to rise.

Oxytocin is the hormone responsible for contractions of the uterus. There is always some oxytocin in your system, but too much can kick off premature labor.

You might find Can Dehydration Cause You To Go Into Labour? an informative read.

If you are dehydrated for an extended period of time, it could lower the levels of amniotic fluid surrounding your baby. This is called oligohydramnios.

If fluid levels are consistently low, this could affect your baby’s growth, resulting in preterm birth.

Signs of preterm labor

It’s vital to contact your health care provider immediately if you have any signs or symptoms of preterm labor and you’re not yet 37 weeks pregnant.

Possible symptoms of preterm labor are:

• Cramp-like pains in the lower abdomen and back that are persistent and might increase in intensity
• Any sort of vaginal bleeding or vaginal discharge
• Your waters have broken
• Nausea, vomiting, and diarrhea.

You might like to read Signs Of Labor | 7 Signs Your Baby Is On The Way and 7 Signs That Labor Is 24 To 48 Hours Away.

Braxton Hicks or preterm labor?

Braxton Hicks contractions are practice contractions that prepare you for labor. Some women might experience these contractions quite early in pregnancy.

Braxton Hicks tighten your tummy as labor contractions do, but they are painless and usually settle and go away if you move or rest.

Labor contractions don’t settle; they become progressively more painful and intense. The contractions might initially be quite far apart and then start to get closer together.

Contact your midwife or health care provider if you are unsure whether or not you’re in labor.

Read more about the difference in our article Braxton Hicks Contractions – What Are They?

Preterm labor treatment

Treatment for early labor depends on what gestation you are at the time of labor.

The important thing to remember is immediate medical assistance can make a huge difference. The aim is usually to slow down premature labor, or stop it from happening, for as long as possible.

Treatment for preterm labor might include:

• Bed rest – at home or in the hospital
• Tocolytic medicines – to help slow or stop contractions
• Steroids – to help your baby’s lungs to grow and mature. Preterm babies often need help with breathing after they’re born
• Cervical cerclage – a procedure used to stitch the cervix closed. It may be done when the cervix is weak and not able to stay closed
• Antibiotics – given if symptoms of preterm labor indicate infection
• Birth of the baby. The doctor might recommend birthing your baby if treatments don’t stop preterm labor. You might need a c-section but this will depend on a number of factors.

Medications for treatment of preterm labor

There are a number of different medications that can be used for treatment of premature birth. If you have any symptoms of preterm labor, your healthcare providers will try to determine the best treatment option for you, depending on how many weeks pregnant you are, and how baby is coping.

Betamethasone

This can be given through injection into the mother’s arm, legs, or buttocks. It then travels through her bloodstream to reach the baby. It’s usually given 2 to 4 times over two days. It’s most effective from 2 to 7 days after the first dose.

Betamethasone is a steroid that is given to help the baby’s lungs cope with the transition from receiving oxygen via the placenta to breathing air.

Preterm babies might not have enough surfactant, which is a substance inside the lungs that helps them to function. This steroid aims to speed up the process of surfactant production in the lungs of babies born early.

Some side effects of Betamethasone include:

• Elevated blood sugar
• Trembling or dizziness
• Low potassium
• Skin changes.

Magnesium sulfate

This is a tocolytic medication used to delay birth for 48 hours or more. Tocolytic drugs are used to delay the birth of your baby for a short time if you begin labor too early in your pregnancy.

Magnesium sulfate is more commonly used now instead of an older drug called terbutaline, which is no longer considered safe for injection.

Studies are showing magnesium sulfate could protect the baby’s nervous system in preterm labor, preventing brain injuries.

This medication is given into the vein, and both the mother and baby are closely monitored for any sign of complications.

Some of the side effects of this medication are:

• Feeling of warmth
• Flushing
• Nausea and vomiting
• Thirst
• Headache
• Dizziness.

Nifedipine

This medication is another tocolytic medication used to delay birth for 48 hours or more. It’s usually used for high blood pressure and is given to the mother to try to relax the uterus, and stop contractions in premature birth.

It is usually given orally for rapid absorption in premature birth.

As with all medications, Nifedipine has side effects, such as dizziness due to low blood pressure, increased heart rate, and raised glucose levels.

Terbutaline

This medication is a synthetic form of the stress hormone called epinephrine. This hormone causes the smooth muscles in the uterus to relax rather than contract.

Some of the side effects of Terbutaline are:

• A racing heartbeat, flushing, tremors, and restlessness
• In around 1-5% of women, irregular heartbeat, extra fluid in the lungs (pulmonary edema), and chest pain
• Raised blood sugar levels in diabetic women
• In babies, a raised heart rate and blood sugar levels.

Terbutaline isn’t recommended for women with heart disease, hyperthyroidism, and poorly controlled diabetes.

Can preterm labor be stopped?

If there are preexisting conditions, it’s less likely labor can be stopped once it begins. It isn’t fully understood why babies are born prematurely.

Medications are used to try to stop contractions by relaxing the uterus. The aim is to slow the onset of preterm labor and premature birth. This gives health care providers time to try to prepare baby’s lungs for life outside the womb.

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When should I go to hospital for preterm labor?

If you have any symptoms of preterm labor, or you suspect you’re in preterm labor, call your midwife or hospital immediately and make plans to head into hospital as soon as possible.

It’s a good idea to have a hospital bag ready, so that if preterm labor begins you’re ready to go. This is especially important if you have had preterm births before, or you have known risk factors that mean you might birth early.

If need be, pack for a possible extended stay, and include your essential items, such as snacks, comfy clothes, and mobile phone chargers.

For more tips on packing hospital bags, check out Hospital Bag For Labor – What To Pack?

What happens to premature babies?

Premature babies can do quite well but it depends how many weeks gestation they are.

A premature birth closer to 37 weeks means a baby is more developed and closer to being able to survive outside the womb with little assistance. The hospital pediatrician will assess her and if all appears well, your baby will not need to be in the special care unit.

However, if baby is closer to 28 weeks, she will need assistance after a preterm birth. Your baby might be transferred to the neonatal intensive care unit for specialist care in an oxygen-controlled humidity crib.

Some babies will require IV therapy, which provides extra fluids, and might also need extra help with their breathing.

Of course, all decisions about your baby’s care require your informed consent and should be discussed and explained by your health care provider.

More detailed information can be found in Premature Babies – What To Expect Week By Week.