A baby is normally born after 40 weeks of intrauterine development and is ready to face the outside world without any medical help in most situations. However, in special situations, the baby may be unable to complete the journey of full nine months and get spontaneously or artificially delivered at a much earlier date. If the baby is delivered before 36 weeks of intrauterine life, some of the vital organ functions in the baby may be inadequately developed, requiring supportive care in a hospital nursery and even admission to newborn intensive care unit. However, if the baby is born between 36 to 40 weeks of intrauterine life, the baby may need minimal support or none at all.
Preterm labour is when the mother goes into labour before 37 weeks. ‘Late preterm birth’ is the term used when babies are born between 34 to 37 weeks. These babies do not look very premature and may or may not need admission to a neonatal intensive care unit, but they are at risk for more problems than babies born at term. Most of the time, there is no cause for preterm labour. Medical conditions in the mother like diabetes, heart disease, kidney disease, and certain auto immune conditions can lead to preterm births. Multiple pregnancies account for about 15 per cent of all premature births. There are numerous pregnancy related problems that increase the risk of preterm labour. The common reasons for preterm delivery are high blood pressure in mother, weak outlet of uterus, baby with anomaly, urinary tract infection in mother, and poor socioeconomic status. It is not uncommon for babies born early to have intra-uterine growth restriction.
A premature baby has a lower birth weight than a full term baby and all organ functions have variable degree of maturity, depending on how early in the intrauterine life the baby has been delivered. The most common and serious is breathing difficulties (respiratory distress syndrome), or abnormal breathing patterns (apnoea). These babies are less active and have lower muscle tone and less baby fat. Female infants have an enlarged clitoris and male infants might have undescended testis. Feeding problems are due to poor sucking and suck-swallow in coordination.
Many of these babies may need to stay in neonatal intensive care unit for a few weeks followed by a few weeks in nursery. Premature babies may need special drug therapy to increase the elasticity of lung and improve oxygen exchange known as surfactant. Along with this drug therapy, they may need assisted breathing with different modes of ventilation. Assisted breathing can be with nasal cannulae or intubation of trachea (windpipe) depending on the severity of lung abnormality. Breathing problem due to immature lung is often referred to as respiratory distress syndrome. These babies are unable to handle their sugar levels and are prone to metabolic abnormalities, leading to risk of seizures. These premature babies are at potential risk of infection at all times, far in excess of normal babies as their defence mechanism for infection is immature. The risk of infection and poor oxygen delivery to brain leaves the baby at risk of bleeding inside the brain and its attendant morbidity later in life.
Since most premature babies’ liver function is also immature, jaundice is extremely common. Majority respond to a period of phototherapy and few may need exchange of blood. Since their ability to produce and replace blood cells is also immature, they may need transfusion of blood components. Many of them do not tolerate feeds, particularly formula feed, and the intestines may develop a dreaded infectious complication known as necrotising enterocolitis. Necrotising enterocolitis may progress to a stage where emergency surgery may be needed to save life.
Since the premature baby is an at-risk baby who has the potential to grow into a normal baby with specialised supportive care, the baby should be delivered in centres which have a team who specialise in supporting premature babies sail through the turbulence of coming into the world before time. The unit where the baby has to be delivered should have specialised paediatricians who are dedicated to the problems and experts in treatment of prematurity related problems and are called neonatologists. Since the care of these babies is a 24×7 affair for many weeks, in general any centre with a team of neonatologists is likely to do a better job with premature babies than with an isolated expert struggling with the complications of a premature baby.
The job of a neonatologist starts right from receiving the baby in the labour room, assisting it to breathe and keeping it in an environment artificially created for the baby called an incubator. The baby may also be nursed in the neonatal intensive care unit in a special cot, which has a radiant warmer that will help maintain its temperature. The baby is monitored with devices that are usually placed on it to monitor its breathing, heart rate and oxygen levels in the blood. If the breathing problems are not responding to simple measures, the baby may need a tube to be placed into its trachea (wind pipe), and a substance called surfactant would be instilled to help with breathing. Some babies who have less breathing problems may need CPAP (continuous positive airway pressure) where a tube is placed in the baby’s nose, while others only need oxygen.
The baby may need regular blood gas analysis and tests to check glucose, calcium and electrolytes. While supporting the baby’s breathing, chest X-rays and blood gas levels may be necessary. Ultrasounds of the baby’s brain are routinely done for the premature babies to look for bleeding in the brain.
After several weeks of care the vast majority of babies return home. Depending on the severity of organ immaturity and expertise of newborn care, several long term problems may require follow up as outpatient. A small proportion of babies may need to continue oxygen at home due to minor damage to lungs, which may be reversible called bronchopulmonary dysplasia. These babies need continuous monitoring of eyes, ear, growth and development. A few may need on-going treatment. The more premature an infant and the lesser the birth weight, the greater the risk of complications. However, it is impossible to predict a baby’s long-term outcome based on gestation age or birth weight.
Antenatal care reduces the risk of preterm delivery. A steroid medication given to pregnant women reduces the severity of complications of premature birth. The problems of a premature baby are best treated by moving mothers for delivery to centres of excellence with a team of neonatologists, where they can be protected and supported in their last few weeks’ journey, which could not be completed within the uterus. Majority of them can grow up as normal babies, a few may challenge the experience and skill of the most experienced neonatologist and neonatal units, eventually coming home to live and grow with little support at home, eventually adding to the joy of their family!
The best ways to prevent prematurity are to:
• Be in good health before getting pregnant
• Get prenatal care as early as possible in the pregnancy
• Continue to get prenatal care until the baby is born