Weight of the baby

While the average full-term baby weighs about 3 kg at birth a premature newborn might weigh 2.25 kg or even considerably less. But thanks to medical advances children born after 28 weeks of pregnancy and weighing more than 1 kg have almost a full chance of survival. Some premature babies need to spend time in a hospital’s newborn intensive care unit (NICU).

The earlier in pregnancy a baby is born the more likely he/she is to have health issues. The doctor might use these terms to describe the baby’s birth:

Late preterm – Born between 34 and 36 completed weeks of pregnancy
Moderately preterm – Born between 32 and 34 weeks of pregnancy
Very preterm – Born at less than 32 weeks of pregnancy
Extremely preterm – Born at or before 25 weeks of pregnancy

Do premature babies need special medical care?

The earlier your baby arrives the smaller he/she will be the larger the head will seem in relation to the rest of the body and the less fat the baby will have. As the baby has no protective fat the premature baby will get cold in normal room temperatures. For that reason the baby has to be placed immediately after birth in an incubator or under a special heating device called a radiant warmer.

Here the temperature can be adjusted to keep the baby warm. Most of the preterm babies have a good chance of healthy survival with special newborn care. Babies born before 34 weeks of pregnancy are most likely to have health problems but babies born between 34 and 37 weeks of pregnancy are also at increased risk of having health problems related to premature birth.

Causes of Preterm Birth | Prashanth Hospitals

Common Causes of Preterm Birth

Preterm birth happens when a baby is born before 37 completed weeks of pregnancy. In many cases, it can occur unexpectedly. However, certain medical and lifestyle factors can increase the risk. Understanding these risk factors helps in early monitoring and timely care and in identifying the causes of preterm birth at the right time.

Below are some of the most common causes and risk factors linked to preterm labor and the major causes of preterm birth.

1. Prior Preterm Birth

If you have had a preterm birth in a previous pregnancy, the chances of it happening again are higher. A previous history remains one of the strongest Causes of Preterm Birth and should be discussed early with your doctor.

Your doctor may:

Monitor your pregnancy more closely
Recommend medications or cervical support if needed
Advise lifestyle changes to reduce risk

Early antenatal visits are especially important in this situation to understand possible causes of premature birth in your case.

2. Short Gap Between Pregnancies

Having pregnancies very close together (less than 6–12 months apart) can increase the risk of preterm labor. Short pregnancy spacing is often considered among the common causes of preterm birth.

Your body needs time to:

Recover from the previous pregnancy
Restore nutrient levels
Heal physically and emotionally

Family planning and spacing pregnancies can help lower this risk and reduce preventable causes of premature birth.

3. Multiple Pregnancy (Twins or Triplets)

Carrying twins, triplets, or more increases pressure on the uterus. This can lead to:

Early stretching of the uterus
Early contractions
Increased chances of preterm delivery

Regular scans and close monitoring are essential in multiple pregnancies, as they are recognised causes of preterm birth due to increased uterine stress.

4. Problems with the Uterus or Cervix

Certain structural conditions can increase risk, such as:

Incompetent cervix (cervical insufficiency) – when the cervix opens too early without pain
Abnormal shape of the uterus
Previous surgeries on the cervix

In some cases, a procedure called a cervical stitch (cerclage) may be advised to help support the pregnancy and prevent complications related to structural Causes of Preterm Birth.

5. Maternal Health Conditions

Chronic medical conditions can increase the risk of premature labor, including:

High blood pressure
Diabetes
Thyroid disorders
Kidney disease
Autoimmune conditions

Good control of these conditions before and during pregnancy plays a key role in reducing complications and lowering the risk of preterm birth complications.

Both extremes can affect pregnancy:

Being overweight or obese – linked to high blood pressure and gestational diabetes
Being underweight – may affect fetal growth and overall pregnancy health

Maintaining a healthy weight before pregnancy supports better outcomes.

7. Smoking, Alcohol, or Drug Use

Substance use during pregnancy can:

Affect placental function
Reduce oxygen supply to the baby
Trigger early labor

Stopping smoking, alcohol, and drug use as early as possible greatly improves pregnancy safety.

8. Placental Problems

Conditions affecting the placenta can lead to early delivery, such as:

Placental abruption – when the placenta separates from the uterus before delivery
Placental infection
Poor placental blood flow

These conditions may cause bleeding, abdominal pain, or reduced baby movements and require immediate medical attention.

9. Hormonal Changes and Infections

Certain infections and hormonal imbalances can trigger uterine contractions.

Common examples include:

Urinary tract infections
Vaginal infections
Untreated sexually transmitted infections
Inflammation of the uterus

Many infections can be treated easily when detected early. Regular prenatal check-ups help identify these issues and address underlying Causes of Preterm Birth before they progress.

Warning Signs of Preterm Labor

Contact your doctor immediately if you notice:

Regular tightening or contractions before 37 weeks
Lower back pain that does not go away
Pelvic pressure
Vaginal bleeding or spotting
Leaking fluid from the vagina
Change in vaginal discharge

Early medical care can sometimes delay labor and improve outcomes for the baby.

Baby Growth Chart by Gestational Age

Understanding your baby’s growth during pregnancy can be reassuring. Below is an approximate guide to average weight, length, and head circumference at different gestational ages.

These values are averages. Individual babies may vary slightly.

Baby Growth by Gestational Age – Boys

Gestational Age	Average Weight	Average Length	Head Circumference
40 Weeks	3.6 kg	51 cm	35 cm
35 Weeks	2.5 kg	46 cm	32 cm
32 Weeks	1.8 kg	42 cm	29.5 cm
28 Weeks	1.1 kg	36.5 cm	26 cm
24 Weeks	0.65 kg	31 cm	22 cm

Baby Growth by Gestational Age – Girls

Gestational Age	Average Weight	Average Length	Head Circumference
40 Weeks	3.4 kg	51 cm	35 cm
35 Weeks	2.4 kg	45 cm	31.5 cm
32 Weeks	1.7 kg	42 cm	29 cm
28 Weeks	1.0 kg	36 cm	25 cm
24 Weeks	0.60 kg	32 cm	21 cm

What Do These Measurements Mean?

Weight

Gives an idea of overall growth and nutritional health inside the womb.

Length

Shows skeletal and body development.

Head Circumference

Reflects brain growth and development.

Important to Remember

Ultrasound estimates may vary slightly from actual birth measurements.
Preterm babies may need additional monitoring after delivery.
Regular antenatal visits help track healthy fetal growth.

If you have concerns about your baby’s growth or scan reports, consult your obstetrician for proper guidance and reassurance.

Best Neonatal Care Hospital in Chennai

After a quick examination in the delivery room the baby might be moved to the NICU upon the specialist’s advice. If the baby is premature or needs surgical care he/she will be cared for in our exclusive Neonatal Intensive Care Unit (NICU). Prashanth Hospitals has one of the best NICU in Chennai. While some risk factors cannot be changed there are a few general ways to reduce the odds of having a premature birth. You can have antenatal appointments more often and you will have extra tests and checks to make sure that you and your baby ore doing fine.

Prashanth Hospitals houses the most advanced facilities like high-end intensive care unit ventilators CPAP machines incubators ECMO which is available only in a few centers in Chennai maternal ICU exclusively for mothers with complex health issues Pediatric ICU and 24 hours ICU availability with the best specialists to treat mothers as well as newborns. If you think you are experiencing preterm labor it is important that you see a doctor right away.

Frequently Asked Questions

When a baby is born too soon (before 37 weeks), organs like the lungs, brain, and heart may not be fully developed. This can cause breathing problems, feeding difficulties, infections, and temperature instability. With proper neonatal care, most premature babies can grow and thrive, but some may need long-term medical follow-up.

Born Too Soon: A Decade of Action on Preterm Birth is a global report released by the World Health Organization (WHO) and partners in 2023. It highlights progress and challenges in reducing premature births, calls for stronger maternal-newborn care, and urges countries to invest in preventing and managing preterm birth.

Some premature babies, especially those born very early, may face higher risks of learning difficulties, ADHD, anxiety, or developmental delays. However, early intervention, therapy, and supportive environments can significantly improve cognitive and emotional outcomes. Most preterm children lead healthy, normal lives with proper medical and developmental support.

Preterm labor can sometimes be delayed for a few days to 2 weeks using medications like tocolytics and corticosteroids. These treatments help mature the baby’s lungs and reduce complications. However, the success depends on the mother’s health, cervical dilation, and underlying cause of early labor. Continuous hospital monitoring is essential.