What has an effect on birthweight?

However, normal weight encompasses a large spectrum. In industrial nations normal birthweight is roughly between 2500 g and 4500 g, whereby the average healthy weight of babies at birth according to WHO is between 3000 g and 3500 g. 

Initially, it is the genes which play a crucial role in determining the birthweight. If both parents are tall, it is generally true to say that they have bigger and heavier offspring than smaller couples. The ethnic background is yet another aspect. Whereas Indian children are born with an average weight of 2975 g and are some of the lightest newborns worldwide, babies in Norway have an average birthweight of 3575 g. The gender of the child is also a decisive factor. Baby boys, for instance, are generally taller and heavier than baby girls. Differences were also recorded between a single newborn and a multiple birth. In pregnancies with twins or more, the birthweight usually decreases in accordance with an increasing number of babies. 

If there are multiple factors which impact the weight at birth, numerous studies have shown that it was primarily maternal factors, including age, build, lifestyle habits and how the pregnancy evolved which determined the child’s weight at birth. The mother’s build, for example, plays a more dominant role than that of the father. A mother’s excess weight or obesity during pregnancy not only impacts the birthweight, it also increases the chances that the mother may suffer complications during the pregnancy or at birth. On the other hand, these women are more likely to run the risk of having premature births and other complications which, in turn, are associated with a lower birthweight. 

Another key factor is the age of the mother when she has her first child. For women who give birth at a very young age or have their first child when they are older than 35, there is a greater tendency that their newborn weighs less. Another aspect is the number of previous pregnancies. Accordingly, the firstborn is frequently lighter in weight than their siblings. 

The course of the pregnancy also plays a crucial role in the child’s development, which may be adversely affected as a result of malnutrition, anaemia, high blood pressure and infections suffered by the mother, thus resulting in a lower birthweight. By contrast, a pre-existing diabetes mellitus or diabetes of pregnancy promotes the occurrence of an abnormal foetal size that is characterised by a birth weight above the 95th percentile. 

Nor should factors influenced by a person’s lifestyle before and during pregnancy be ignored. For example, if the mother smokes, drinks alcohol, takes drugs or consumes a lot of coffee, these factors constitute a risk factor in growth impairment of the child. 

Ultimately, the birthweight is the result of a complex list of many genetic, socio-economic and health factors. Consequently, these play a major role in predicting and determining the parameters of the child’s health. And the child’s development should be monitored by means of controlling the child’s weight. There are numerous scales and measurement systems available which are specially tailored to newborns and infants.