Neonatal outcomes after preterm birth

Survival rates for preterm babies have improved steadily over the past two decades due to the introduction of surfactant therapy, improvements in neonatal respiratory management and more widespread use of antenatal steroids. While the number of babies above 24 weeks who

Table 21.1

Survival percent

Gestational

Weight:

Weight:

Weight:

Survival

without major

age

50th centile

10th centile

90th centile

(%)

morbidity

23

600

450

970

6

2

24

700

550

1180

15

5

25

790

620

1250

45

15

26

880

700

1350

60

20

27

960

780

1450

75

50

28

1080

820

1600

85

60

29

1220

940

1720

90

80

30

1400

1050

1900

93

85

31

1600

1180

2100

96

90

32

1760

1300

2300

97

92

33

1980

1480

2500

97

95

34

2200

1650

2700

98

97

survive has increased there has been no improvement in survival at the lower limits of viability below 23 weeks. The Epicure study [1] reported mortality rates of 100, 90 and 80% for preterm infants admitted to the Neonatal Unit at 21, 22 and 23 weeks gestation, respectively. Improved survival for very preterm infants has been associated with an increase in the proportion of children with cerebral palsy who were born preterm. Neonatal mortality rises gradually between 32 and 28 weeks from 2 to 8% and then more dramatically and exponentially to 80% at 23 weeks.

In the past surfactant deficiency leading to neonatal respiratory distress syndrome was the major cause of morbidity and mortality in preterm infants. Alveolar surfactant production begins at 30-32 weeks gestation. Therefore preterm infants born prior to 30 weeks are at highest risk. The impact of respiratory distress syndrome upon neonatal morbidity and mortality has been dramatically reduced in the past two decades through use of antenatal corticosteroids and exogenous surfactant replacement. The risk of chronic lung disease, defined as a need for ventilation or oxygen supplementation at 36 weeks after conception, has continued to rise, however, because of the increased survival of extremely preterm infants. The fetal and neonatal brain is especially susceptible to injury between 20 and 32 weeks post-conception. The greatest risk of long-term neural developmental problems is in infants born before 28 weeks or at birth weights of less than 1 kg. The Epicure study showed that in infants born before 26 weeks gestation approximately half had some disability at 30 months and approximately one quarter had severe disability (Figs 21.1 and 21.2). Cerebral palsy may be related to periventricular haemorrhage, post-haemorrhagic hydrocephalus and periven-tricular leukomalacia. Hypoxic ischaemia is a major risk factor for neonatal cerebral damage. However, there is

□ Other disability (25%) E3 Severe disability (23%)

Fig. 21.1 Outcomes for surviving infants born before 26 weeks' gestation when assessed at 30 months. Adapted from Wood NS et al. N Engl J Med. (2000) 10; 343(6): 378-4 and Colvin M et al. (2004) Br Med J 329, 1390-3.

Haematogenous Cervical infection Iatrogenic weakness I infection

Periventricular Inflammation Neonate
Fig. 21.2 The innerplay of causes of the 'preterm labour syndrome'.

growing evidence for a strong link between chorionam-nionitis, fetal inflammation and the risk of periventricular leukomalacia.

The risk of visual impairment due to retinopathy of prematurity is inversely related to gestational age and directly related to the concentration and duration of

□ Other disability (25%) E3 Severe disability (23%)

oxygen treatment. Despite improvements in the management of oxygen therapy, most infants born before 28 weeks gestation will develop some form of retinopathy. The risk of retinopathy of prematurity rises dramatically from less than 10% at 26 weeks to above 50% in infants born at 24 weeks. About 3% infants born before 28 weeks gestation will require a hearing aid and 50% will be found to have learning difficulties at school requiring additional educational support.

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Pregnancy Diet Plan

Pregnancy Diet Plan

The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.

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