Read Oxford Handbook of Midwifery Online
Authors: Janet Medforth,Sue Battersby,Maggie Evans,Beverley Marsh,Angela Walker
CHAPTER 23
Care of the newborn
628
Management of the small for gestational age baby
Definition
A small for gestational age baby is any baby whose weight falls below the 10th percentile for its gestational age.
1
A baby can be premature and small for dates, or term and small for dates, for example:
Determination
Causes
The small for gestational age baby will have been starved
in utero
due to poor placental supply of nutrients. Some of the causes relate to poor maternal health, others relate to socio-economic factors, and some are fetal, for example:
•
Congenital infection
There may be genetic and racial inheritance reasons why babies appear small when weighed and measured using standard percentile charts designed for the average European Caucasian population. This is often the case for babies of Asian origin. Also, occasionally, it may also be linked to poor diet and health, where the mother, living in a different culture, finds it difficult to obtain food she would normally enjoy.
2
Due to poor nourishment from the placenta, the fetus is unable to lay down any spare stores of fat or glycogen and, once born, the baby will have difficulty in maintaining temperature and blood glucose levels.
MANAGEMENT OF THE SMALL FOR GESTATIONAL AGE BABY
629
need to be managed as a preterm baby (b see Management of the preterm baby, p. 634).
Poor fetal growth may indicate placental failure and, without intervention, the fetus may die. Caesarean section may be carried out when the fetus reaches a viable age.
3
Growth restriction
Growth of a fetus is referred to as symmetrical or asymmetrical, and is diagnosed using ultrasound scanning, when various measurements are taken:
Asymmetrical babies
Symmetrical babies
Congenital abnormalities
Small for gestational age may also be associated with some congenital abnormalities, such as trisomies (where there is an extra chromosome), leading to conditions such as Down’s and Edward’s syndromes.
3
Congenital infections
Babies with congenital infections tend to be small for dates.
CHAPTER 23
Care of the newborn
630
Taking the first letter from each name of an infection in this group spells out the word TORCH:
TORCH screening is the test carried out on the placenta and blood to detect these infections.
1
Characteristics of a small for gestational age baby
At birth the baby:
Management at birth
Taking the above factors into consideration, management will depend on the gestation and condition of the baby at birth.
If on examination major problems are ruled out, care will entail management of:
MANAGEMENT OF THE SMALL FOR GESTATIONAL AGE BABY
631
Glucose homeostasis
Small for gestational age babies have long been identified at risk of hypoglycaemia, due to: