What is the difference between preterm labor and threatened preterm labor? What are the conditions and survival rates by number of weeks [supervised by a physician]?

What is premature birth?

Premature birth is birth between 22 weeks 0 days and 36 weeks 6 days of pregnancy. By the way, birth at the normal time (birth between 37 weeks 0 days and 41 weeks 6 days of pregnancy) is called “full term birth”. If the baby is born before 22 weeks of pregnancy, it is considered to be unable to survive, and unfortunately it will result in a miscarriage. 

It is said that premature birth occurs in approximately 5% of all pregnancies. There are two types of premature birth: “spontaneous premature birth,” in which labor begins early and the baby is born, and “induced premature birth,” in which the baby cannot survive in the uterus for some reason and is forced to be born artificially. Approximately 75% of premature births are spontaneous premature births.

The difference between preterm labor and premature birth

Threatened premature labor is a state where you are on the verge of premature birth, that is, one step before premature birth. It refers to a state where the cervix (the opening of the uterus) is about to open, and if appropriate measures are not taken, the baby is likely to be born at any moment. On the other hand, premature birth refers to the fact that the baby is born before 22 to 37 weeks of pregnancy.

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Causes of Premature Birth

The main causes of premature birth are

• Bacterial infection or cervical incompetence (a condition in which the cervix becomes loose and opens even when it is not time to give birth)
• Abnormalities in the uterus itself (such as uterine fibroids or uterine malformations)
• Pregnancy-induced hypertension, placenta previa (placenta blocking the cervix)
• Placental abruption (placenta detaches from the uterine wall)
• Fetal distress (unhealthy fetus)

And more. 

In addition, premature birth is not only a problem for the mother, but also a cause of congenital infections and chromosomal abnormalities in the baby. Hiro Clinic NIPT (New Prenatal Testing) is a method that can detect the risk of chromosomal abnormalities in the baby early by simply taking a blood sample from the mother .

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Tendency to premature birth

The following people are known to be more likely to have a premature birth: 

•  Maternal age (35 years or older, minor)
•  Pregnancy within six months of previous birth
•  Those who have had premature birth in previous pregnancies
•  Those with a short cervix
•  People who have had a cervical conization
•  Multiple births (twins, triplets, etc.)
•  Bacterial vaginosis (a type of infection in the vagina)
•  Those who have had a shortened cervix confirmed by ultrasound examination

 In addition, smoking, being underweight (BMI below 18.5), and working long hours or heavy work can also make you more likely to suffer from premature birth, so be careful.

Risk to the mother

The risk to the mother is no different from that of a normal childbirth as long as there is no infection of the uterus.

Risks to the baby

The risk to the baby depends on how early it is and how much it weighs when it is born. The earlier it is, the higher the chance of the baby dying, as it will be underweight if it is in the womb for a short time.

If a baby is born with a low birth weight, its organs and tissues are not yet fully developed and it is unable to breathe on its own. Therefore, it requires support from a ventilator to survive and will be treated in a neonatal intensive care unit (NICU) for a long period of time. 

It is also known that the lower the birth weight, the higher the chance of the baby having a residual disability. Although it cannot be said in general, the chance of the baby having a severe residual disability such as cerebral palsy is quite high at 10-20% for babies weighing less than 1000g, but less than 5% for babies weighing 1500g or more.

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When can premature birth be cured?

The benchmark for when premature birth can be prevented is said to be the 22nd week of pregnancy, when the baby weighs more than 500g. Therefore, births up to 21 weeks and 6 days of pregnancy are unfortunately considered to be unlikely for the baby to survive, and are distinguished as miscarriages.

Preterm birth status and survival rate by week 

Although it is generally referred to as premature birth, the baby’s subsequent condition will vary greatly depending on whether the baby is born at 22 weeks of pregnancy or in the later stages of pregnancy, close to full term.

Premature birth at 25 weeks of pregnancy

The survival rate of premature babies born at 24-25 weeks of pregnancy is 86.5%. At this time, the average baby’s weight increases to 600-700g, and in modern medicine, babies weighing 700g or more at birth have a survival rate of over 90%. After birth, they will need to be treated in the NICU for a long period of time.

Premature birth at 30 weeks

Babies born prematurely at 30-31 weeks of pregnancy have over a 97% chance of surviving, and most babies are able to be discharged from hospital safely.

However, babies are said to be able to breathe on their own only around the 34th week of pregnancy, and still require the assistance of a ventilator. After birth, they will need to be treated in the NICU.

Premature birth at 6 months of pregnancy

Being 6 months pregnant means you are between 20 and 23 weeks pregnant.

In other words, if a baby is born in the first half of the sixth month of pregnancy (20-21 weeks), it is considered a miscarriage, not a premature birth. Babies born at 22-23 weeks have not yet developed bodily functions and cannot breathe on their own, so they require long-term treatment in the NICU. Also, the more premature a baby is, the more likely it is to develop serious disabilities later on.

Therefore, if there is a possibility of premature labor at 6 months of pregnancy, we will hospitalize the mother as necessary or have her rest at home so that the baby can stay in the womb for as long as possible. If the pregnancy cannot be maintained and birth is unavoidable, the mother may be rushed to a specialized hospital with a NICU.

Premature birth at 7 months of pregnancy

Being 7 months pregnant means you are between 24 and 27 weeks pregnant.

The baby’s weight is gradually increasing, and the functions of the body and organs are developing, but they are not yet complete. In particular, the function of the eyes is not yet fully developed, and babies born before 28 weeks of pregnancy are more likely to suffer from neonatal retinopathy.

As with premature birth at 6 months of pregnancy, if there is a possibility of premature birth at this stage, treatment will be given to keep the baby in the womb for as long as possible. If premature birth is unavoidable, the baby may be rushed to a specialized hospital with a NICU.

9 months pregnant: Threatened premature birth

Being 9 months pregnant means you are between 32 and 35 weeks pregnant.

At this time, it is not uncommon for the baby to weigh more than 2000g. Babies born before 34 weeks of pregnancy often require NICU care, but there are many babies who do not require special medical treatment.

However, careful monitoring is required as symptoms such as breathing problems, jaundice, and developmental delays may occur.

Preterm labor later in pregnancy

Symptoms that may indicate preterm labor in the later stages of pregnancy include bleeding, changes in vaginal discharge, and abdominal distension.

Things to be careful of to avoid premature birth

In order to prevent preterm labor and premature birth, it is most important to have regular prenatal checkups. Prenatal checkups check for any tendency to preterm labor, so if you are instructed to rest or reduce salt intake, be sure to follow the instructions. 

It is also important to try not to push yourself too hard during your pregnancy. If your doctor tells you to “rest,” it is advisable to consult with your workplace and take time off work. When it comes to housework, leave it to family members if possible.

If you absolutely have to work or do housework, be sure to avoid standing for long periods of time, slouching, and not carrying heavy objects. It is also effective to keep your body warm.

Smoking can also cause premature birth. If you are pregnant and have not yet quit smoking, quit now.

summary

Above, we have summarized what premature birth is, the difference between premature birth and threatened premature birth, the condition and survival rate of premature birth by week, and what to be careful of to avoid premature birth.

If you experience any symptoms that may indicate premature labor, such as bleeding, changes in vaginal discharge, or abdominal distension, see your doctor as soon as possible.

If you experience regular contractions every 10 minutes or your water breaks, contact your hospital immediately, even if you are not close to due date.

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