Verified on 04/25/2022 by PasseportSanté
We speak of hypotrophy when the baby is born at term, but his birth weight is lower than the norm. Always a source of concern for young parents, the weight and good growth of a newborn are at the center of their concerns. What are the causes of this hypotrophy? Do affected babies require special care? Appropriate support? Here are some answers.
What is a hypotrophic baby?
Hypotrophy is defined by a weight below the 10th percentile in a given population of the same gestational age. For a term pregnancy, a baby is considered hypotrophic by the WHO if its birth weight is less than 2.5 kg.
This hypotrophy is a continuation of intrauterine growth retardation, which was not corrected at birth.
Hypotrophy is frequent, since it concerns by definition the 10% of newborns whose birth weight is the lowest. It is considered that approximately 3% suffer from severe hypotrophy.
Intrauterine growth restriction can be suspected by the midwife at the time of fundal height measurement, which offers an estimate of fetal growth. It will then be confirmed by the sonographer, with the measurements of the size of the fetus and the estimate of its weight.
In cases where the growth delay is not caught up and the baby is born with measurements below the 10th percentile: he is diagnosed as hypotrophic.
Some growth retardations are also not diagnosed during pregnancy, so the diagnosis is made at birth only.
What are the causes of hypotrophy?
There are a number of risk factors for intrauterine growth retardation and hypotrophy. The most common are:
- Preeclampsia: this disease is characterized by poor vascularization of the fetus during pregnancy. Intrauterine growth restriction and hypotrophy are very common complications of preeclampsia;
- Infectious causes: when certain viruses – such as toxoplasmosis, rubella or cytomegaliovirus – are contracted during pregnancy, they can impact the proper growth of the fetus;
- Substance abuse during pregnancy: tobacco, alcohol, drugs, etc. ;
- Certain drug treatments, such as beta-blockers;
- Congenital malformations;
- Malnutrition of the woman during pregnancy or eating disorders;
- Certain uterine malformations;
- A low maternal age (below 18 years old or high (above 40 years old);
- Multiple pregnancies.
Symptoms of an underweight baby
Beyond short stature, underweight babies typically have low muscle mass and decreased subcutaneous fatty tissue, which give them hollow features, which may be reminiscent of those of an older person. Apart from these physical characteristics, their appearance and behavior are those of a baby of normal weight.
What can be the complications of hypotrophy?
When hypotrophy is detected during pregnancy, it can lead to several types of complication at the time of childbirth:
- hypoglycaemia during the first hours of the baby’s life, requiring an injection of glucose;
- hypothermia, due to the low proportion of subcutaneous fat and low nutrient reserves. Skin to skin with the mother is then very beneficial, and if it is not enough, a passage in an incubator may be necessary;
- Perinatal asphyxia when growth retardation is linked to placental insufficiency. A caesarean section is then indicated;
- A meconium aspiration syndrome, which corresponds to the inhalation of amniotic fluid loaded with meconium;
- An increased risk of neonatal jaundice, also known as infant jaundice.
After delivery, the hypotrophic baby has a greater risk of being transferred to the neonatology department, or even to intensive care in the event of meconium aspiration syndrome, for example. It will take longer to come out of the maternity ward than a normal weight baby, depending on his weight gain.
Back home: what precautions with a hypotrophic baby?
Back home, the parents of a hypotrophic baby will have to check the baby’s good food intake and weight gain. If breastfeeding, it is recommended that they:
- count the layers of urine and stool;
- check the quality of the suction and the length of the feedings.
In case of doubt or difficulty, the mother can be accompanied by a lactation consultant who can give her the appropriate advice.
Finally, it is recommended that parents of hypotrophic babies approach the PMI (Protection Maternal Infantile) closest to their home, in order to regularly monitor the good growth of the child.
Most low-birth-weight babies born at term eventually catch up. It is thus estimated that 80% catch up with normal weight and height, children still lagging behind at a year and a half of life being likely to benefit from treatment with growth hormone.