Premature birth

Generality

A birth is defined as premature, or preterm, when it takes place at least three weeks before the fortieth and last week of pregnancy.

Depending on when it occurs, premature birth has different consequences for the unborn child; in general, the child is born first and the complications that are created are more serious.

Premature babies show unequivocal anatomical signs, such as low weight, and different symptoms, the severity of which depends on the week of birth.

The therapy aims to moderate the symptomatology, so that the child can conclude that process of growth in utero, interrupted too early due to premature birth.

What is premature birth

A premature or preterm birth is a birth that takes place at least three weeks before the expected date of birth. In other words, since the theoretical duration of a normal gestation is 40 weeks, a birth is considered premature if it takes place between the 20th and 37th week.

In detail, we talk about:

• Late premature birth, if the baby is born between the 34th and 37th week of pregnancy.
• Severe premature birth, if the baby is born between the 25th and 33rd week of pregnancy.
• Extreme premature birth, if the baby is born before 25th week.

The permanence of the fetus in the uterus, until the end of pregnancy, is essential for the correct development of the child's organs and for its post-natal growth. On the other hand, before birth occurs and the subsequent consequences, suffered by the unborn child, will be more serious.

WHEN DO YOU SPEAK ABOUT PART-BY-TIME OR DEPARTURE AFTER THE TERM?

To complete the definition framework, it is right to clarify what is meant by term delivery and delivery after the deadline.

The term birth is the birth that occurs between the 37th and 42nd week. Postpartum birth is what happens after the 42nd week.

Starting from the 37th week, the possibility that fetal development is incomplete is increasingly reduced; however, it is not excluded that complications of another nature may still arise.

Epidemiology

According to the Italian Society of Neonatology ( SIN ), in Italy, every year, about 7% of children born alive come to light before the 37th week. This means that, out of a total of around 514, 000 newborns in 2013, almost 36, 000 children were born of premature birth.

Moreover, still on the basis of the statistical data of the SIN, the mortality of premature babies is around 10%; in general, the survival rate is as low as the birth takes place as soon as possible.

A study on the breeds and frequency of preterm birth in the various ethnic groups around the world showed that black women are inexplicably more prone to premature birth.

Causes

The precise causes that cause premature birth have not yet been identified; on the other hand, however, different risk conditions have been identified, having a decisive role. In this regard, it is good to specify that the preterm parties can take place even in the absence of any risk factor.

RISK FACTORS

The chances of a premature birth increase with the following risk factors or conditions :

• Women who, previously, were the protagonists of a premature birth.
• Multiple pregnancy (for multiple, s'intende twin).
• Two pregnancies too close together over time. Generally, when less than six months pass from each other.
• In vitro fertilization .
• Problems with the uterus, cervix, or placenta.
• Smoking, drinking alcohol and using illegal drugs during pregnancy.
• Malnutrition of the mother, which obviously affects the fetus.
• Infections, affecting the mother, that develop in the amniotic fluid or in the lower genital tract.
• Women suffering from chronic pathological conditions, such as hypertension and diabetes .
• Women who were underweight or overweight before becoming pregnant.
• Mothers victims of strong emotional stress.
• Women who have had a miscarriage in the past.
• Mothers victims of injuries and physical traumas.
• Unusual form of the uterus.

Symptoms and Complications

The premature baby is a child who has not spent enough time in the womb to develop and grow properly. In other words, it comes to light with organs (lungs, brain, heart, etc.) not yet fully formed. All this makes its adaptation to the outside world more difficult and reduces its survival capacity; these difficulties are all the more accentuated the more preterm is the birth.

The premature baby shows characteristic signs and can develop very serious short and long term complications.

CHARACTERISTIC SIGNS

Babies born of premature birth may present the following characteristic signs:

• Extremely small body size, but very large head (in proportion)
• Acute and less roundish facial features than a child born at term
• Thin, transparent and fragile skin
• Thin hair ( lanugo ), which covers almost the whole body
• Hypotension (low blood pressure), especially immediately after birth
• Difficult breathing and respiratory distress
• Lack of so-called neonatal reflexes, or the reflexes of sucking and swallowing. This implies that the child has difficulty eating

Deepening: what is respiratory distress?

Respiratory distress, or respiratory distress syndrome, is a typical (but not exclusive) condition of premature infants, which causes respiratory failure . This condition is due to an incomplete development of the lungs, which cannot adequately supply the entire body with oxygen. In most cases, the lungs are missing or lacking a fundamental substance to keep them healthy and make them work better: the surfactant (from the English surfactant ), consisting of proteins and lipids.

Surfactant production begins between the 24th and 28th week and is completed around the 34th. Therefore, the more a child is born in advance, compared to the term, the less surfactant contains in the lungs.

SHORT-TERM COMPLICATIONS

The short-term complications are those that arise immediately after the birth of a premature baby.

They consist of:

• Respiratory problems . They are due to an underdeveloped respiratory system, or to lungs that do not seem able to supply the entire body with oxygen. The main cause of these respiratory disorders is the lack of surfactant. Babies, especially those born between the 23rd and 32nd week, develop a chronic lung disease known as bronchopulmonary dysplasia, and are prone to apnea episodes.
• Heart problems . Premature babies develop two disorders, which are hypotension and the so-called patent ductus arteriosus .

  Hypotension is an excessively low blood pressure, while the patent arterial duct is an anatomical anomaly of the heart, in which the aorta and pulmonary artery communicate with each other, through an opening. This defect, in reality, is considered as such only if it is maintained at birth, since all children (even those born at term), inside the mother's belly have the patent ductus arteriosus.

• Neurological problems . The children, who come to light before the 28th week of gestation, are at high risk of developing intraventricular bleeding in the brain. In some individuals, these blood losses are moderate, while in other infants they are extremely severe and can give rise to a pathological condition, known as hydrocephalus . Hydrocephalus is the accumulation of cerebrospinal fluid (or CSF ) in the cerebral ventricles.
• Problems in body temperature control . Premature babies have little adipose tissue and are therefore unable to maintain their body heat at adequate levels. Therefore, they are very often subject to hypothermia, ie a low body temperature. Hypothermia has several consequences: it aggravates respiratory problems, lowers blood glucose levels ( hypoglycemia ) and hinders growth. In particular, the obstacle to growth is due to the fact that food, taken by the preterm infant, is used to produce heat, which is the first necessity, rather than for growth.
• Gastrointestinal problems . Premature babies have an immature gastrointestinal system and tend to suffer from necrotizing enterocolitis . It is a serious pathological condition, characterized by the death of the cells that make up the intestinal wall.
• Blood problems . Premature babies are at high risk of anemia and jaundice . Anemia is a deficiency of red blood cells, or blood cells that carry oxygen to the various organs of the body; jaundice is an excessive accumulation of bilirubin in the blood, which makes the skin, eyes and other body tissues yellow.
• Metabolism problems . Serious and extreme premature suffer very often from hypoglycemia.
• Immune system problems . The immune system is the defensive barrier of our body against infectious agents (viruses, bacteria, parasites etc.) present in the external environment. Preterm children have an underdeveloped immune system, so they are more exposed to infections and related complications (for example, sepsis ).

Figure: newborn with respiratory distress.

LONG TERM COMPLICATIONS

Long-term complications are those complications that can appear weeks, months, or even years, from premature birth.

They consist of:

• Infant cerebral palsy .
• Reduced cognitive abilities . Very often, especially in more severe cases, premature babies do not enjoy the same cognitive and learning abilities as a child born at term. These disorders become obvious when the preterm child begins to go to school.
• Vision problems . Preterms, born before the 30th week, tend to suffer from the so-called premature retinopathy ( ROP ).

  The ROP is a vascular disease of the retina, which in some cases can lead to a detachment of the retina itself. Retinal detachment is a condition that, if not treated promptly, can cause loss of vision.

• Hearing problems . Premature babies are more likely to lose their acoustic ability.
• Dental problems . It is possible to observe: a delay in the eruption of the teeth, a discoloration of the tooth enamel and an incorrect alignment of the teeth.
• Behavioral and psychological problems . Premature babies are more likely to experience depression, sense of anxiety, attention deficit syndrome, hyperactivity and difficulty in interacting with peers.
• Chronic health problems . Among premature babies, there is a predisposition to chronically develop infections, asthma and problems related to poor nutrition.

Table. Average measures of weight, length and head circumference, in full-term children and premature babies.

Diagnosis

The diagnosis of premature birth does not require special investigations: it is sufficient, in fact, to make a consideration about when the birth took place and to observe the appearance of the baby, measuring weight, body length and head size.

To understand what the risks and possible complications of preterm labor might be, first of all we begin with an objective examination and a monitoring of respiratory and cardiac capacities.

Then, we move on to an accurate blood test, a measure of lost body fluids, a check on the main internal organs (instrumental tests) and, finally, an eye exam.

EXAMINATION OBJECTIVE

The objective examination consists in the general evaluation of the state of health of the premature baby. It is during this check that the doctor outlines what the symptomatology is and what the next diagnostic path must be.

MONITORING OF RESPIRATORY AND HEART RATES

The respiratory and cardiac abilities of the premature baby are the most monitored characteristics by the medical staff, as it is precisely their compromise that often causes the most serious health problems.

Breathing, heart rate and blood pressure are very frequently checked; even, in the most risky cases, they are kept under continuous observation.

BLOOD ANALYSIS

Blood tests measure the levels of circulating red blood cells, glucose, calcium and bilirubin. The medical staff only performs the number of samples strictly necessary, since depriving an already weak, and in some cases anemic, child of blood is very dangerous.

CONTROL OF BODY FLUIDS

To control body fluids, we mainly mean the measurement of how much sodium and potassium are lost with urine and faeces.

CONTROL OF INTERNAL BODIES: INSTRUMENTAL EXAMINATIONS

In general, the first instrumental examination to be performed is the echocardiogram . This, in fact, is an ultrasound of the heart that serves to see its anatomy and possible defects.

The second instrumental examination, instead, consists in the ultrasound of the abdominal organs (in particular intestine, stomach and liver) and of the brain. If there are abnormalities, such as intraventricular bleeding, these are highlighted.

VISUAL CONTROL

An ophthalmologist examines the sight and the various structures of the eye (retina, crystalline etc.), in search of some of their anomalies.

Treatment

A child born of premature birth needs different care, depending on how serious the situation is. If in moderate cases a supportive therapy and the administration of certain medicines are sufficient, in extreme cases the use of surgery may also be necessary.

Once the situation has stabilized, the newborn can be discharged; at home, however, he may need to receive other care, so it is good that parents are informed about what to do in case of sudden complications.

SUPPORT THERAPY

Supportive and pharmacological treatments include the following treatments:

• Growth in an incubator . The incubator is a special medical device, which houses premature babies and guarantees them proper oxygenation, the right body temperature and the right nutrition for their growth. Moreover, without moving the child from where it is stored, it allows to check the various body parameters, such as heart rate, blood pressure, weight, etc. In other words, with the incubator it is intended to restore, in the best possible way, the life of the fetus inside the uterus. It is clear that the results cannot be the same, however with assisted ventilation and a vein supply or via nasogastric tube, it is possible to try to treat even very complicated situations.
• Exposure to fluorescent light, for the treatment of jaundice . There are particular lamps that emit a fluorescent light capable of "breaking down" the blood bilirubin. Premature babies are exposed to these lamps for jaundice treatment. Exposure is done at intervals of time and requires that protective glasses be worn on the newborn.
• Blood transfusion . The transfused blood serves to restore any deficiencies of red blood cells (anemia).
• Surfactant infusion . The surfactant is sprayed into the lungs, to favor normalization of respiratory activity and oxygenation of the various organs.
• Antibiotics . They are used for the prevention and treatment of bacterial infections.

SURGERY

Figure: newborn in an incubator.

Faced with the appearance of certain complications, surgery is required. In particular:

• necrotizing enterocolitis requires the removal of the damaged intestine.
• The patent ductus arteriosus, if it does not spontaneously close at birth, requires artificial closure (of the opening between the aorta and the pulmonary artery).
• The retinopathy of the prematurity is treated with a laser, which removes the excess of blood vessels formed on the retina.

• The hydrocephalus is treated with a ventriculostomy operation, that is with a drainage of the cerebral ventricles full of cerebrospinal fluid.

RESIGNATION REQUIREMENTS

Once the premature baby has received all the necessary care, it has reached a suitable body weight and is able to:

• Breathe without assisted ventilation
• Keep the right body temperature on your own
• Feed yourself, both breast and artificially

he can be dismissed and taken home by his parents, who are informed about everything that is needed in these circumstances.

Prognosis and prevention

For a child born of premature birth, the prognosis depends largely on when it was born. As stated above, in fact, first the preterm birth occurs and the consequences on the newborn are more serious. Furthermore, it should not be forgotten that, in the face of serious complications, it is even more difficult to provide effective care.

The severe and extreme premature births often have a rapid and ominous course; late ones can have more or less severe long-term repercussions.

PREVENTION

To try to prevent premature birth, it is essential that a mother knows how to recognize the warning signs and the ways in which she presents herself (see the table). In this way, in fact, it is possible to promptly contact your doctor or hospital, to undergo the checks and appropriate care.

It is important to point out that, even when intervening in time, it is not always possible to stop early labor and, consequently, prevent premature labor.

Table. The signs of a premature birth.

• Contractions every ten minutes or less
• Loss of blood and liquids of different nature from the vagina
• Sense of pressure in correspondence of the pelvic area, as if the child was a prerequisite
• Dull pain in the lower back
• Cramps similar to those of a menstruation
• Abdominal cramps with or without diarrhea