Preterm birth

Preterm birth (premature birth) is a significant public health problem across the world because of associated neonatal (first 28 days of life) mortality and short- and long-term morbidity and disability in later life. Preterm is defined by World Health Organization (WHO) as babies born alive before 37 completed weeks of gestation or fewer than 259 days of gestation since the first day of a woman’s last menstrual period (LMP). Normally, a pregnancy lasts about 40 weeks.

According to WHO, every year about 15 million babies are born prematurely around the world and that is more than one in 10 of all babies born globally. Almost 1 million children die each year due to complications of preterm birth (2013). Across 184 countries, the rate of preterm birth ranges from 5% to 18% of babies born. In India, out of 27 million babies born every year (2010 data), 3.5 million babies born are premature.

Newborn deaths (those in the first month of life) account for 40 percent of all deaths among children under five years of age. Preterm birth is the world’s number one cause of newborn deaths, and the second leading cause of all child deaths under five, after pneumonia.

Many of the preterm babies who survive suffer from various disabilities like cerebral palsy, sensory deficits, learning disabilities and respiratory illnesses. The morbidity associated with preterm birth often extends to later life, resulting in physical, psychological and economic stress to the individual and the family.

Though occurrence of preterm birth is a global problem, but more than 60% of preterm births occur in Africa and South Asia. In the lower-income countries, on average, 12% of babies are born too early compared with 9% in higher-income countries. Within countries, poorer families are at higher risk. Survival of premature babies also depends on where they are born; almost 9 out of every 10 preterm babies survive in high-income countries because of enhanced basic care and awareness, in sharp contrast to about 1 out of 10 in low-income countries.

More than three-quarters of preterm /premature babies can be saved with often inexpensive care such as essential care during child birth, antenatal steroid injections (given to pregnant women at risk of preterm labour under set criteria to strengthen the babies’ lungs) and postnatal care like kangaroo mother care (the baby is carried by the mother with skin-to-skin contact and frequent breastfeeding), and basic care for infections and breathing difficulties.

Identification of risk factors in women with improved care before, between and during pregnancies; better access to contraceptives and increased empowerment/ education can further decrease the preterm birth rate (the number of preterm births divided by the number of live births).


Preterm is defined as babies born alive before 37 weeks of pregnancy or fewer than 259 days of gestation are completed since the first day of a woman’s last menstrual period (LMP). There are sub-categories of preterm birth, based on gestational age:

  • extremely preterm (<28 weeks)
  •  very preterm (28 to <32 weeks)
  •  moderate to late preterm (32 to <37 weeks)

Various methods for detection of gestational age-

  • Early ultrasound scan: estimation of fetal crown-rump length, biparietal diameter / femur length between gestational ages 6 – 18 weeks.
  • Fundal Height: distance from pubis symphysis to fundus.
  • Last menstrual period: women’s recall of the date of the first day of her last menstrual period.
  • Newborn examination: validated scores using external +/or neurological examination.
  • Best obstetric estimate: uses an algorithm to estimate gestational age based on best information available, commonly used in high-income settings.

Signs of preterm labor- 

In most cases, preterm labor begins unexpectedly and the cause is unknown. Like regular labor, signs of early labor are—

  • Change in vaginal discharge (a significant increase in the amount of discharge or leaking fluid or bleeding from the vagina).
  • Contractions (the abdomen tightens like a fist) every 10 minutes or more often.
  • Pelvic pressure—the feeling that the baby is pushing down.
  • Low, dull backache.
  • Cramps that feel like a menstrual period.
  • Abdominal cramps with or without diarrhea.



Preterm birth is a syndrome with a variety of causes which can be classified into two broad subtypes:

(1) Spontaneous preterm birth: may occur after spontaneous onset of labor or following prelabour premature rupture of membranes (PPROM).The cause of spontaneous preterm labor cannot be unidentified in up to half of all cases.

(2) Provider-initiated preterm birth is defined as induction of labor or elective caesarian birth before 37 completed weeks of gestation for maternal or fetal indications (both “urgent” and “discretionary”), or other non-medical reasons.

Most preterm births occurs spontaneously but some are due to early induction of labour or caesarean birth, whether for medical or non-medical reasons.

Approximately 45–50% of preterm births are idiopathic (unknown cause), 30% are related to preterm rupture of membranes (PROM) and another 15–20% are attributed to medically indicated or elective preterm deliveries.

Risk factors for preterm birth-

  • Age at pregnancy: adolescent pregnancy and advanced maternal age
  • Previous preterm birth
  • Multiple pregnancies (such as twins, triplets)
  • Infections and chronic conditions such as diabetes and high blood pressure
  • Genetic influences
  • Nutritional: under nutrition, obesity, micronutrient deficiencies
  • Life style-Women who smoke cigarettes, drink alcohol or take other recreational drugs are at a higher risk of having preterm babies. Stress from any cause, excessive physical work or long times spent standing are also known to increase a woman’s risk of having preterm birth.

However, often no cause is identified.



To date, there is no single test or sequence of assessment measures to accurately predict preterm birth. Clinical, biophysical, and biochemical tests that can be used as predictors for preterm birth are:

Clinical predictors- Identification of clinical risk factors, symptoms like pelvic pressure, increased vaginal discharge/changed in vaginal discharge, backache, and menstrual-like cramps.

Biophysical predictors-

  • Uterine contraction monitoring during pregnancy- Uterine contractions can be detected through maternal self-perception, and by medical personnel and by electronic monitoring.
  • Cervical Examination-
    • Manual examination for cervical dilatation, effacement, consistency, position, and station of the presenting part can be determined by manual examination. Cervical dilatation and effacement have been related to an increased risk of preterm birth.
    • Sonographic evaluation: A decreased cervical length as measured by endovaginal ultrasound examination has also been related to an increased risk of preterm birth.

Fetal fibronectin; in the vaginal discharge may be measured. The presence of this protein is linked to preterm birth.

Tests for Preterm/ premature baby may include-

  • Cardio-respiratory monitoring: baby's breathing and heart rate are monitored on a continuous basis.
  • Fluid input and output is monitored in determining fluid requirements in very low birth weight babies.
  • Blood tests: to know about complete blood count, white blood cell (WBC) count, blood type and antibody testing (Coombs test), serum sodium, potassium, calcium, glucose and bilirubin levels in baby's blood.
  • Echocardiogram: This test is an ultrasound of the heart to check for problems with structure and function of baby's heart.
  • Ultrasound scan: Ultrasound scans may be done to check the brain for bleeding or fluid buildup or to examine the abdominal organs for problems in the gastrointestinal tract, liver or kidneys.
  • Eye examination: An ophthalmologist (eye doctor) may examine baby’s eyes and vision to check for problems with the retina (retinopathy of prematurity).

If baby develops any complications, other specialized testing may be needed.


Management of preterm birth incorporates the specialized care of women during pregnancy and child birth along with care of newborn (preterm) baby.

(a) Care during pregnancy and child birth-

Some women are at increased risk of preterm delivery which can be identified during their antenatal care visits, based on following factors-

  • Obstetric history (e.g., known uterine or cervical anomaly or previous preterm birth).
  • Presenting pregnancy characteristics (e.g., hypertensive disorder of pregnancy, diabetes, multiple gestation, bleeding).
  • Young adolescents.

Women who are identified at risk of preterm delivery or in preterm labour should give birth at a health facility (hospital) where more advanced, specialized care is available for mothers and their babies. The safest time for referral to such type of hospital is when the baby is still in the womb.

Once preterm labor has started, there are interventions that can prolong pregnancy and improve health outcomes and survival for the premature baby. Interventions to prolong pregnancy include the provision of tocolytic agents that inhibit uterine contractions to suppress labor (e.g., oxytocin antagonists, betamimetics, calcium channel blockers, magnesium sulphate).

The other three interventions that can be provided during the pregnancy period will help in improving health outcomes of the premature baby: antenatal corticosteroids, antibiotics for prelabour premature rupture of membranes (PPROM), and magnesium sulphate.

  • Use of antenatal corticosteroids- Women in preterm labour, before 34 weeks of pregnancy have been completed, should receive steroid injections to speed up the development of the baby’s lungs. The administration of antenatal corticosteroids to pregnant women at high risk of preterm birth (as early as 23 weeks) can reduce the premature baby’s risk of death, respiratory distress and developmental problems.
  • Use of antibiotics for prelabour premature rupture of membranes (PPROM)- Premature rupture of the membranes is strongly associated with infection of the amniotic membranes contributing to preterm birth and other poor fetal outcomes such as cerebral palsy and chronic lung disease. Antibiotic treatment for PPROM may delay onset of labor for up to 48 hours and reduce neonatal infections.

 (Amoxicillin and clavulanic acid combination (such as co-amoxiclav) should be avoided in women at risk of preterm delivery because of the increased risk of neonatal necrotizing enterocolitis.*)

  • Use of magnesium sulphate- The administration of magnesium sulphate to women at risk of preterm birth before 32 weeks of gestation helps to protect the baby’s brain, reduce rates of cerebral palsy and improve long-term neonatal health outcomes.

(b)Special care for newborn (preterm) baby-

Preterm baby needs special care because -

Preterm babies are not fully developed to live in the world outside their mother’s womb. Therefore they need special care along with same care that other babies get to overcome the following challenges-    

Keeping warm:

Preterm babies lose body heat more easily, which may result in to hypothermia. Hence they need extra energy and care to stay warm and grow. Babies should be kept warm right after birth; they should be dried thoroughly and placed on their mother’s abdomen. After the umbilical cord has been clamped and cut and if they breathe normally they should be put on their mother’s chest, with skin-to-skin contact, until after the first breastfeed. They should not be bathed right away.


The lungs of preterm babies are not fully developed and lack surfactant (a substance that helps keep the lungs expanded). Many preterm babies start breathing on their own, when they are born, but others need to be resuscitated (newborn resuscitation or ventilation with a bag and mask). If breathing problems persist, they may need additional support from a machine (ventilator) and extra oxygen.Sometimes, some premature babies that have started breathing are not strong enough to continue on their own and exhaust themselves and may stop breathing (apnoea). Constant supervision is required for such babies.


Preterm babies may need additional support for feeding as the coordinated suck and swallow reflex is not yet fully developed. Breast milk is the best nutrition for preterm babies. Babies should be breastfed as soon as possible after birth. Most premature babies who are unable to coordinate the suck and swallow reflex can be fed their mother’s expressed breast milk by cup, spoon or nasogastric tube. Breast is best: just like full-term babies.


The immune systems of preterm babies are not fully developed therefore they are more susceptible to infections. If they get an infection, they have a higher risk of dying.

Preterm babies should be protected from infections by:

  • Gloves and cutting devices used for clamping and cutting the umbilical cord should be sterile,
  • Everyone who touches the mother or the baby should have clean hands.
  • Medical examinations and procedures should only be done if necessary.
  • Babies who have infections need treatment with antibiotics.     


Preterm babies are at risk of bleeding in the brain, during birth and in the first few days after birth. Lack of oxygen can also cause brain injuries. Bleeding or lack of oxygen to the brain can result in cerebral palsy, developmental delays and learning difficulties


Preterm babies’ eyes can be damaged by abnormal growth of blood vessels in the retina. The condition is usually more severe in very premature babies and if they are given too-high a level of oxygen. This can result in visual impairment or blindness.

Care for preterm babies with complications:

Babies who have additional complications may need to be kept in neonatal intensive care units (NICU). Hospitals with NICU can provide specialized care for newborn babies with serious health problems. They have special equipments and specially trained doctors and nurses who provide around-the-clock care for preterm babies, who need extra support to keep warm, to breathe and to be fed, or who are very sick.

As preterm babies (and full-term babies with low birth weight) need extra warmth and support for feeding, Kangaroo Mother Care is a good technique for these babies, if they do not have other serious problems (breathing well with normal heart rate).

Kangaroo Mother Care: is a technique by which the baby is held on an adult’s chest—usually the mother—with skin-to-skin contact, for extended periods of time. The baby is placed on his/her mother’s chest and stays there, day and night, held in place by a cloth that is wrapped and tied at the mother’s back. It is an effective way to meet a premature baby’s needs for warmth, frequent breastfeeding, protection from infection, stimulation, safety and love. It also improves bonding between mothers and babies.




Because preterm/premature babies are not yet fully developed, they may suffer from various complications such as:

Respiratory Distress Syndrome (RDS): as the lungs of premature baby are immature and lack surfactant in the alveoli, babies may develop RDS. Risk of developing RDS is more in babies below 32 weeks of gestation. This risk can be reduced by antenatal corticosteroids injections to women at risk of preterm labor, or in preterm labor.

Feeding difficulties: since the coordinated suck and swallow process only starts at 34 weeks of gestation, preterm babies are more likely to aspirate. They need help to feed.

Jaundice is more common in premature babies since the immature liver cannot easily metabolize bilirubin. Once jaundiced, the preterm baby’s brain is at higher risk because blood-brain barrier is less well developed to protect the brain in premature baby.

Severe infections (neonatal sepsis) are leading cause of death in preterm babies due to less developed immune system.

Brain injury due to bleeding in brain (intraventricular hemorrhage) during birth and in the first few days after birth, and hypoxic brain injury (lack of oxygen to the brain) can result in cerebral palsy, developmental delays and learning difficulties.

Necrotizing enterocolitis is a condition affecting the intestinal wall of very premature babies. Formula feeding increases the risk tenfold compared to babies who are fed breast milk alone.

Retinopathy of prematurity is due to abnormal proliferation of the blood vessels around the retina of the eye. It is more severe if the baby is given too high levels of oxygen.

Anemia of prematurity, which often becomes apparent at a few weeks of age due to delay in producing red blood cells as the bone marrow is immature


Prevention of preterm births includes improved quality of care before, between and during pregnancy to decrease occurrence of preterm birth with improved preterm birth outcomes and care of premature babies to reduce deaths and disability among them-

Preconception health and care before pregnancy-

Many women are unaware of how their health before conception may influence their risk of having an adverse outcome of pregnancy. Providing care to women and couples before and between pregnancies (inter-conception care) improves the chances of mothers and babies being healthy.

Consideration of following factors/solutions during the preconception period can improve the health of the pregnant woman and may contribute to prevent preterm births.

  • Prevent pregnancy in adolescence
  • Optimize pre-pregnancy weight- Women who are underweight before pregnancy (body mass index less than 18.5 kg/m2) are at significantly greater risk of having premature, low birth weight newborns. Overweight and obese women (body mass index greater than 25 kg/m2) have a higher risk for preterm births.
  • Healthy eating and physical activity in their daily routine to improve weight and cardiovascular status before pregnancy will reduce the likelihood of developing weight-related complications during gestation.
  • supplementation/fortification of essential foods with micronutrients- multivitamin supplementation( such as folic acid) reduces the risk of congenital malformations((e.g., neural tube defects, congenital heart diseases, urinary tract and limb defects) and the risk of  preeclampsia, thereby decreasing the chances of preterm birth(contributory factors for preterm).
  • Prevent and treat Sexually transmitted infections. (for more details
  • Addressing life-style risks factors by promoting cessation of tobacco use, smoking and restrict exposure to second hand smoke.
  • Screen for, diagnose and manage chronic diseases such as hypertension, diabetes.
  • Promote vaccination of children and adolescents.
  • Prevent unintended pregnancies and promote optimal birth spacing by promoting use of family planning measures, education and increased empowerment of women.
  • Screen for, diagnose and manage mental health disorders and prevent intimate partner violence- maternal stressors such as depression, socioeconomic hardship.

Care during pregnancy-

Basic services that can be delivered during antenatal care packages for all women with a potential impact on reducing preterm birth rates include:

  • Identification of women at high risk of preterm birth; during antenatal care based on obstetric history (e.g., known uterine or cervical anomaly or previous preterm birth) or presenting pregnancy characteristics (e.g., hypertensive disorder of pregnancy, diabetes, multiple gestation, bleeding). Young adolescents also are at greater risk.
  • Screening for and treatment of sexually transmitted diseases and other infections (tuberculosis, malaria, bacterial vaginosis, bacteriuria);
  • Identification and correction of malnutrition and nutrition counseling;
  • Counseling on birth preparedness and complication readiness for identification of early labour and other risk factors; and
  • Behavioural and social support interventions for lifestyle risk factors such as counseling for smoking, secondhand smoke, substance abuse, depression, stress cessation and prevention of violence against women (intimate partner violence).

Care of women in preterm labour to improve health outcomes of the premature baby-

Women who are identified at risk of preterm delivery or in preterm labour should be referred to a health facility (hospital), where more advanced, specialized care is available for mothers and their babies.

Women should reach health facility quite early in labour so that interventions can be started. When preterm labor has commenced there are interventions that can prolong pregnancy and improve health outcomes and survival for the premature baby-.

  • Interventions to prolong pregnancy include the provision of tocolytic agents that inhibit uterine contractions to suppress labor (e.g., oxytocin antagonists, betamimetics, calcium channel blockers, magnesium sulphate).
  • There are three key interventions that can be started during the pregnancy period for improving health outcomes in the premature baby: antenatal corticosteroids, antibiotics for pprom, and magnesium sulphate.
  • Reduce non-medically indicated inductions of labor and cesarean births especially before 39 completed weeks of gestation.

(Births at 37 to 39 weeks still have suboptimal outcomes, and induction or cesarean birth should not be planned before 39 completed weeks unless medically indicated.)

Care of newborn preterm baby-

More than three-quarters of preterm babies could be saved with feasible, cost-effective care, and further reductions are possible through intensive neonatal care. Most preterm births occur after 32 weeks of gestation (84%), and deaths in these babies can be prevented by essential newborn care.

Essential newborn care with extra care including thermal care, breastfeeding support, and infection prevention and management and if needed, neonatal resuscitation should be provided to preterm babies.

Extra care for small babies could be given by promoting Kangaroo Mother Care (carrying the baby skin-to-skin, additional support for breastfeeding), Kangaroo mother care is recommended for the routine care of newborns weighing 2000 g or less at birth, and should be initiated in healthcare facilities as soon as the newborns are clinically stable.

Care for preterm babies with complications:

• Treating infections, including with antibiotics;

• Safe oxygen management and supportive care for respiratory distress syndrome;

• Neonatal intensive care.

                       Everyone has a role to play… everyone can help to prevent preterm births and improve the care of premature babies.



  • PUBLISHED DATE : May 23, 2016
  • PUBLISHED BY : Zahid
  • CREATED / VALIDATED BY : Dr. Aruna Rastogi
  • LAST UPDATED ON : May 23, 2016


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