• Stillbirth – fetus born with no signs of life ≥24 weeks of pregnancy

• Perinatal mortality rate – stillbirths + deaths within the first week per 1000 live births and stillbirths

• Neonatal mortality rate – deaths of liveborn infants within the first 4 weeks after birth per 1000 live births

• Neonate – infant ≤28 days old

• Preterm – gestation <37 weeks of pregnancy

• Term – 37–41 weeks of pregnancy

• Post-term – gestation ≥42 weeks of pregnancy

• Low birthweight (LBW) – <2500 g

• Very low birthweight (VLBW) – <1500 g

• Extremely low birthweight (ELBW) – <1000 g

• Small for gestational age – birthweight <10th centile for gestational age

• Large for gestational age – birthweight >90th centile for gestational age.

Pre-pregnancy care

The better a mother’s state of health and nutrition, and the higher her socioeconomic living standard and the quality of healthcare she receives, the greater is the chance of a successful outcome to her pregnancy.

Couples planning to have a baby often ask what they should do to optimise their chances of having a healthy child. They can be informed that for the mother:

Any pre-existing maternal medical condition (e.g. hypertension, HIV) or obstetric risk factors for complications of pregnancy or delivery (e.g. recurrent miscarriage or previous preterm delivery) should be identified and treated or monitored. Obesity increases the risk of developing gestational diabetes and pregnancy-induced hypertension.

Couples at increased risk of inherited disorders should receive genetic counselling before pregnancy. They can then be fully informed, decide whether or not to proceed, and consider antenatal diagnosis if available. Pregnancies at increased risk of fetal abnormality include those in which:

Antenatal diagnosis

Antenatal diagnosis has become available for an increasing number of disorders. Screening tests performed on maternal blood and ultrasound of the fetus are listed in Box 9.1. The main diagnostic techniques for antenatal diagnosis are maternal serum screening, detailed ultrasound scanning, chorionic villus sampling (at >10 weeks of pregnancy) and amniocentesis (>15 weeks) (Fig. 9.1). In some rare conditions, preimplantation genetic diagnosis (PGD) allows genetic analysis of cells from a developing embryo before transfer to the uterus. The structural malformations and other lesions which can be identified on ultrasound are listed in Box 9.2, with an example in Figure 9.2.

• reassurance where disorders are not detected

• optimal obstetric management of the mother and fetus

• interventions for a limited number of conditions, such as relieving bladder obstruction or draining pleural effusions, to improve perinatal outcome

• counselling and neonatal management to be planned in advance

• the option of termination of pregnancy to be offered for severe disorders affecting the fetus (see Case History 9.1) or compromising maternal health.

Fetal medicine

The fetus can sometimes be treated by giving medication to the mother. Examples include:

Example of antenatal diagnosis-gastroschisis

Case History

9.1 Antenatal diagnosis

A routine ultrasound scan at 18 weeks’ gestation identified an abnormal ‘lemon-shaped’ skull (Fig. 9.3). This, together with an abnormal appearance of the cerebellum, is the Arnold–Chiari malformation, which is associated with spina bifida. An extensive spinal defect was confirmed on ultrasound. Dilatation of the cerebral ventricles and talipes already present in this fetus suggested a severe spinal lesion. After counselling, the parents decided to terminate the pregnancy.

There are a few conditions where therapy can be given to the fetus directly:

Fetal surgery

Fetal surgery is a relatively new development with varying results. Procedures which have been performed include:

Outcome has mostly been very poor because of the severity of the conditions treated. Careful case selection and follow-up are required to ensure that these novel forms of treatment are of long-term benefit.

Mothers with pre-eclampsia may require preterm delivery because of the maternal risks of eclampsia and of cerebrovascular accident or the fetal risks associated with placental insufficiency and growth restriction. Determining the optimal time for preterm delivery requires an evaluation of the risk to the mother and fetus of allowing the pregnancy to continue compared with the neonatal complications associated with pre-term birth.

Women with insulin-dependent diabetes find it more difficult to maintain good diabetic control during pregnancy and have an increased insulin requirement. Poorly-controlled maternal diabetes is associated with polyhydramnios and pre-eclampsia, increased rate of early fetal loss, congenital malformations and late unexplained intrauterine death. Ketoacidosis carries a high fetal mortality. With meticulous attention to diabetic control, the perinatal mortality rate is now only slightly greater than in non-diabetics. The National Institute for Health and Clinical Excellence (NICE) has produced guidance on the management of diabetes and its complications from preconception to the postnatal period. The emphasis is on aiming for good control of blood glucose.

Fetal problems associated with maternal diabetes are:

• Congenital malformations. Overall, there is a 6% risk of congenital malformations, a three-fold increase compared with the non-diabetic population. The range of anomalies is similar to that for the general population, apart from an increased incidence of cardiac malformations, sacral agenesis (caudal regression syndrome) and hypoplastic left colon, although the latter two conditions are rare. Studies show that good diabetic control periconceptionally reduces the risk of congenital malformations.

• Intrauterine growth restriction (IUGR). There is a three-fold increase in growth restriction in mothers with long-standing microvascular disease.

• Macrosomia (Fig. 9.4). Maternal hyperglycaemia causes fetal hyperglycaemia as glucose crosses the placenta. As insulin does not cross the placenta, the fetus responds with increased secretion of insulin, which promotes growth by increasing both cell number and size. About 25% of such infants have a birthweight greater than 4 kg compared with 8% of non-diabetics. The macrosomia predisposes to cephalopelvic disproportion, birth asphyxia, shoulder dystocia and brachial plexus injury.

Neonatal problems include:

Gestational diabetes is when carbohydrate intolerance occurs only during pregnancy. Its definition and method of identification remain controversial. It is more common in women who are obese and in those of Afro-Caribbean and Asian ethnicity. The incidence of macrosomia and its complications is similar to that of the insulin-dependent diabetic mother, but the incidence of congenital malformations is not increased. However, there are an increasing number of mothers with type 2 non-insulin dependent diabetes, associated with the increase in obesity in the population. Their fetuses are also at increased risk of congenital malformations.

Maternal drugs affecting the fetus

Relatively few drugs are known definitely to damage the fetus (Table 9.1), but it is clearly advisable for pregnant women to avoid taking medicines unless it is essential. While the teratogenicity of a drug may be recognised if it causes malformations which are severe and distinctive, as with limb shortening following thalidomide ingestion, milder and less distinctive abnormalities may go unrecognised.

The problem of establishing a link may be compounded by a delay of months or years before any problems present. An example of this is diethylstilboestrol (DES), given in the past for threatened miscarriage, and its subsequent association with vaginal adenosis and carcinoma of the vagina and cervix in female offspring during adolescence or early adult life.

Alcohol and smoking

Excessive alcohol ingestion during pregnancy is sometimes associated with the ‘fetal alcohol syndrome’. Its clinical features are growth restriction, characteristic face (Fig. 9.5), developmental delay and cardiac defects (up to 70%). The effects of less severe ingestion and binge-drinking remain uncertain but may affect growth and development, and mothers are advised to avoid alcohol (Department of Health, London, UK). Maternal cigarette smoking is associated in the fetus with an increased risk of miscarriage and stillbirth, a reduction in birthweight and IUGR (see pre-pregnancy care, earlier in this chapter).

Congenital infections

Intrauterine infection is usually from maternal primary infection during pregnancy. Those that can damage the fetus are:

Cytomegalovirus

CMV is the most common congenital infection, affecting 3–4/1000 live births in the UK, with higher rates reported in parts of the USA. In Europe, 50% of pregnant women are susceptible to CMV. About 1% of susceptible women will have a primary infection during pregnancy, and in about 40% of them the infant becomes infected. The infant may also become infected following an episode of recurrent infection in the mother, but this is much less likely to damage the fetus. When an infant is infected:

• 90% are normal at birth and develop normally

• 5% have clinical features at birth, such as hepatosplenomegaly and petechiae (Fig. 9.6b), most of whom will have neurodevelopmental disabilities such as sensorineural hearing loss, cerebral palsy, epilepsy and cognitive impairment

• 5% develop problems later in life, mainly sensorineural hearing loss.

Congenital infections

Infection in the pregnant woman is usually asymptomatic or causes a mild non-specific illness. There is no CMV vaccine and pregnant women are not screened for CMV. Antiviral therapy for infected infants with ganciclovir is under investigation in randomised controlled trials.

Adaptation to extrauterine life

In the fetus, the lungs are filled with fluid, and oxygen is supplied by the placenta. The blood vessels that supply and drain the lungs are constricted (high pulmonary vascular resistance), so most blood from the right side of the heart bypasses the lungs and flows through the ductus arteriosus into the aorta, and some flows across the foramen ovale (Fig. 9.7). Shortly before and during labour, lung liquid production is reduced. During descent through the birth canal, the infant’s chest is squeezed and some lung liquid drained. Multiple stimuli, including thermal, tactile and hormonal (with a particularly dramatic increase in catecholamine levels), initiate breathing. On average, the first breath occurs 6 s after delivery. Lung expansion is generated by intrathoracic negative pressure and a functional residual capacity is established. The mean time to establish regular breathing is 30 s. Once the infant gasps, the majority of the remaining lung fluid is absorbed into the lymphatic and pulmonary circulation.

Pulmonary expansion at birth is associated with a rise in oxygen tension, and with falling pulmonary vascular resistance the pulmonary blood flow increases. Increased left atrial filling results in a rise in the left atrial pressure with closure of the foramen ovale. The flow of oxygenated blood through the ductus arteriosus causes physiological, and eventual anatomical, ductal closure. After an elective caesarean section, when the mother has not been in labour and the infant’s chest has not been squeezed through the birth canal, it may take several hours for the lung fluid to be completely absorbed, causing rapid, laboured breathing (transient tachypnoea of the newborn).

Some infants do not breathe at birth. This may be due to asphyxia, when the fetus experiences a lack of oxygen during labour and/or delivery. It does not necessarily mean that the brain has been injured but asphyxia can lead to brain injury or death. A fetus deprived of oxygen in utero will attempt to breathe, but if this is unsuccessful (as it will be in utero), it will then become apnoeic (primary apnoea), during which time the heart rate is maintained. If oxygen deprivation continues, primary apnoea is followed by irregular gasping and then a second period of apnoea (secondary or terminal apnoea), when the heart rate and blood pressure fall. If delivered at this stage, the infant will only recover if help with lung expansion is provided, e.g. by positive pressure ventilation by mask or tracheal tube (Fig. 9.8).

The human fetus rarely experiences a continuous asphyxial insult, except after placental abruption or complete occlusion of umbilical blood flow in a cord prolapse. More commonly, asphyxia, which occurs during labour and delivery is intermittent, e.g. from prolonged and frequent uterine contractions. Although birth asphyxia is an important cause of failure to establish breathing requiring resuscitation at birth, there are other causes, including birth trauma, maternal analgesic or anaesthetic agents, retained lung fluid, preterm infant or a congenital malformation which interferes with breathing.

The Apgar score is used to describe a baby’s condition at 1 and 5 min after delivery (Table 9.2). It is also measured at 5-min intervals thereafter, if the infant’s condition remains poor. The most important components are the heart rate and respiration.

Neonatal resuscitation

Most infants do not require any resuscitation. Shortly after birth, the baby will take a breath or cry, establish regular breathing and become pink. The baby can be handed directly to his or her mother, and covered with a warm towel to avoid becoming cold. However, a newborn infant who does not establish normal respiration directly will need to be transferred to a resuscitation table for further assessment (Fig. 9.9a). There should be an overhead radiant heater and the infant should be dried and partially covered and kept warm. Suction of the mouth and nose is normally unnecessary and vigorous suction of the back of the throat may provoke bradycardia from vagal stimulation. If the infant’s breathing in the first minute of life is irregular or shallow, but the heart rate is satisfactory (>100 beats/min), breathing is encouraged with airway opening manoeuvres.

If the infant does not start to breathe, or if the heart rate drops below 100 beats/min, airway positioning and lung inflation by breathing by mask ventilation are started (Fig. 9.9b–f). If the baby’s condition does not improve promptly, or if the infant is clearly in very poor condition at birth, additional assistance should be summoned immediately while continuing to maintain ventilation. If an attendant has the appropriate skills, tracheal intubation can be performed (Fig. 9.9g).

After tracheal intubation, if the heart rate does not increase and adequate chest movement is not achieved, consider ‘DOPE’:

If there is any uncertainty about the adequacy of ventilation in an intubated baby, consider removing the tracheal tube, give mask ventilation and then re-intubate.

If at any time the heart rate drops below 60 beats/min, provided adequate breathing has been achieved, chest compressions should be given (Fig. 9.9h–j). If the response to ventilation and chest compression remains inadequate, drugs should be given (Fig. 9.9k). Evidence for their efficacy is very poor.

Size at birth

An infant’s gestation and birthweight influence the nature of the medical problems likely to be encountered in the neonatal period. In the UK, 7% of babies are of low birthweight (<2.5 kg). However, they account for about 70% of neonatal deaths.

Definitions

Babies with a birthweight below the 10th centile for their gestational age are called small for gestational age or small-for-dates (Fig. 9.10). The majority of these infants are normal, but small. The incidence of congenital abnormalities and neonatal problems is higher in those whose birthweight falls below the second centile (approximately two standard deviations (SD) below the mean), and some authorities restrict the term to this group of babies. An infant’s birthweight may also be low because of preterm birth, or because the infant is both preterm and small for gestational age.

Small-for-gestational-age infants may have grown normally but are small, or they may have experienced intrauterine growth restriction (IUGR), i.e. they have failed to reach their full genetically determined growth potential and appear thin and malnourished. Babies with a birthweight above the 10th centile may also be malnourished, e.g. a fetus growing along the 80th centile who develops growth failure and whose weight falls to the 20th centile.

Patterns of growth restriction

Growth restriction in both the fetus and infant has traditionally been classified as symmetrical or asymmetrical. In the more common asymmetrical growth restriction, the weight or abdominal circumference lies on a lower centile than that of the head. This occurs when the placenta fails to provide adequate nutrition late in pregnancy but brain growth is relatively spared at the expense of liver glycogen and skin fat (Fig. 9.11). This form of growth restriction is associated with uteroplacental dysfunction secondary to maternal pre-eclampsia, multiple pregnancy, maternal smoking or it may be idiopathic. These infants rapidly put on weight after birth.

In symmetrical growth restriction, the head circumference is equally reduced. It suggests a prolonged period of poor intrauterine growth starting in early pregnancy (or that the gestational age is incorrect). It is usually due to a small but normal fetus, but may be due to a fetal chromosomal disorder or syndrome, a congenital infection, maternal drug and alcohol abuse or a chronic medical condition or malnutrition. These infants are more likely to remain small permanently.

In practice, distinction between asymmetrical and symmetrical growth restriction often cannot be made.

Routine examination of the newborn infant

Immediately after a baby is born, parents are naturally anxious to know if their baby is alright and appears normal. To answer this, the midwife (or the paediatrician or obstetrician, if present) will briefly but carefully check that the baby is pink, breathing normally and has no major abnormalities. If a significant problem is identified, an experienced paediatrician must explain the situation to the parents. If the baby is markedly preterm, small or ill, admission to a neonatal unit will be required. Should there be any uncertainty about the child’s sex, it is important not to guess but to explain to the parents that further tests are necessary. Babies are given vitamin K at birth to prevent haemorrhagic disease of the newborn unless parents will not give consent.

Within 24 h of birth every baby should have a full and thorough examination, the ‘routine examination of the newborn infant’. Its purpose is to:

Before approaching the mother and baby, the obstetric and neonatal notes must be checked to identify relevant information. The examination (Fig. 9.12) should be performed with the mother or ideally both parents present. Many findings in the newborn resolve spontaneously (Box 9.5, Fig. 9.13). Common significant abnormalities detectable at birth are listed in Box 9.6. A serious congenital anomaly is present at birth in about 10–15/1000 live births (Table 9.3). In addition, many congenital anomalies, especially of the heart, present clinically at a later age.

Lesions in newborn infants that resolve spontaneously

Box 9.5   Lesions in newborn infants that resolve spontaneously

Peripheral cyanosis of the hands and feet – common in the first day

Traumatic cyanosis from a cord round the baby’s neck or from a face or brow presentation – causes blue discoloration of the skin, petechiae over the head and neck or affected part but not the tongue

Swollen eyelids and distortion of shape of the head from the delivery

Subconjunctival haemorrhages – occur during delivery

Small white pearls along the midline of the palate (Epstein pearls)

Cysts of the gums (epulis) or floor of the mouth (ranula)

Breast enlargement – may occur in newborn babies of either sex (Fig. 9.13a). A small amount of milk may be discharged

White vaginal discharge or small withdrawal bleed in girls. There may be a prolapse of a ring of vaginal mucosa

Capillary haemangioma or ‘stork bites’ – pink macules on the upper eyelids, mid-forehead and nape of the neck are common and arise from distension of the dermal capillaries. Those on the eyelids gradually fade over the first year; those on the neck become covered with hair

Neonatal urticaria (erythema toxicum) – a common rash appearing at 2–3 days of age, consisting of white pinpoint papules at the centre of an erythematous base (Fig. 9.13b). The fluid contains eosinophils. The lesions are concentrated on the trunk; they come and go at different sites

Milia – white pimples on the nose and cheeks, from retention of keratin and sebaceous material in the pilaceous follicles (Fig. 9.13c)

Mongolian blue spots – blue/black macular discoloration at the base of the spine and on the buttocks (Fig. 9.13d); occasionally occur on the legs and other parts of the body. Usually but not invariably in Afro-Caribbean or Asian infants. They fade slowly over the first few years. They are of no significance unless misdiagnosed as bruises

Umbilical hernia – common, particularly in Afro-Caribbean infants. No treatment is indicated as it usually resolves within the first 2–3 years

Positional talipes – the feet often remain in their in-utero position. Unlike true talipes equinovarus, the foot can be fully dorsiflexed to touch the front of the lower leg (Fig. 9.13e,f)

Caput succedaneum (see Fig. 10.6).

Some significant abnormalities detected on routine examination

Box 9.6   Some significant abnormalities detected on routine examination

Port-wine stain (naevus flammeus). Present from birth and usually grows with the infant (Fig. 9.14a). It is due to a vascular malformation of the capillaries in the dermis. Rarely, if along the distribution of the trigeminal nerve, it may be associated with intracranial vascular anomalies (Sturge–Weber syndrome), or severe lesions on the limbs with bone hypertrophy (Klippel–Trenaunay syndrome). Disfiguring lesions can now be improved with laser therapy.

Strawberry naevus (cavernous haemangioma). Often not present at birth, but appear in the first month of life and may be multiple (Fig. 9.14b). It is more common in preterm infants. It increases in size until 3–15 months old, then gradually regresses. No treatment is indicated unless the lesion interferes with vision or the airway. Ulceration or haemorrhage may occur. Thrombocytopenia may occur with large lesions, when therapy with systemic steroids or interferon-α may be required.

Natal teeth consisting of the front lower incisors – may be present at birth. If loose, they should be removed to avoid the risk of aspiration.

Extra digits – are sometimes connected by a thin skin tag but may be completely attached containing bone (Fig. 9.14c) and should ideally be removed by a plastic surgeon or else tied off at its base. Skin tags anterior to the ear and accessory auricles should be removed by a plastic surgeon.

Heart murmur – poses a difficult problem, as most murmurs audible in the first few days of life resolve shortly afterwards. However, some are caused by congenital heart disease. If there are any features of a significant murmur (see Ch. 17), upper and lower limb blood pressures, and pre- and post-ductal pulse oximetry should be checked followed by an echocardiogram. Otherwise, a follow-up examination is arranged and the parents warned to seek medical assistance if their baby feeds poorly, develops laboured breathing or becomes cyanosed.

Midline abnormality over the spine or skull, such as a tuft of hair, swelling or naevus – requires further evaluation as it may indicate an underlying abnormality of the vertebrae, spinal cord or brain.

Palpable and large bladder – if there is urinary outflow obstruction, particularly in boys with posterior urethral valves. Requires prompt evaluation with ultrasound.

Talipes equinovarus – which cannot be corrected as in positional talipes.

Testing for developmental dysplasia of the hip (DDH)

To test for developmental dysplasia of the hip (DDH), also called congenital dislocation of the hip (CDH), the infant needs to be relaxed, as kicking or crying results in tightening of the muscles around the hip and prevents satisfactory examination. The pelvis is stabilised with one hand. With the other hand, the examiner’s middle finger is placed over the greater trochanter and the thumb around the distal medial femur. The hip is held flexed and adducted. The femoral head is gently pushed downwards. If the hip is dislocatable, the femoral head will be pushed posteriorly out of the acetabulum (Fig. 9.15a).

The next part of the examination is to see if the hip can be returned from its dislocated position back into the acetabulum. With the hip abducted, upward leverage is applied (Fig. 9.15b). A dislocated hip will return with a ‘clunk’ into the acetabulum. Ligamentous clicks without any movement of the head of femur are of no significance. It should also be possible to abduct the hips fully, but this may be restricted if the hip is dislocated. Clinical examination does not identify some infants who have hip dysplasia from lack of development of the acetabular shelf. DDH is more common in girls (six-fold increase), if there is a positive family history (20% of affected infants), if the birth is a breech presentation (30% of affected infants) or if the infant has a neuromuscular disorder.

Early recognition of DDH is important as early splinting in abduction reduces long-term morbidity. A specialist orthopaedic opinion should be sought in the management of this condition. Ultrasound examination of the hip joint is performed increasingly in many hospitals, either following an abnormal examination or to screen babies at increased risk (breech presentation or positive family history). Ultrasound examination can be performed to screen all babies, but is not currently recommended in the UK as it is expensive, requires considerable expertise and there are many false positives. It will, however, identify some babies missed on clinical examination.