There’s no disputing that pregnancy is a time of change, but for all sorts of biological reasons, many of us tend to view labour and delivery as the crucible of the whole process. However, science is now proving, without doubt, that the conditions to which a baby is exposed in utero have a long term impact on health and wellbeing.

Most of us know that obesity and overweight have reached epidemic proportions with around two thirds of the population fitting into these categories. Currently more than 60 percent of women within reproductive age are overweight and/or obese.

Am I really hungry?

Whether we acknowledge it or not, most of us also understand that what goes into our mouth and how active we are feeds into our disease risk profile. This creates real issues, particularly in pregnancy, because babies of overweight women tend to be big as well.  This means that her individual risk of developing diseases is increased in both childhood and beyond.

Alarmingly, science has also proven that babies who are overweight or underweight during pregnancy also tend to develop a preference for fatty foods, further increasing their risk of disease.

According to Associate Professor Mark Vickers, Academic Director at the Liggins Institute University of Auckland, the first 1000 days of life from conception until the age of two years represents a major, vulnerable period of programming for non-communicable disease risk and the chances of developing adult disease.  The evidence is clear – there is a greater than 50 percent risk of obesity in children of mothers who gain more weight than the recommended amount during pregnancy.

But aren’t I eating for two?

Conditions such as Type 2 diabetes, cardiovascular disease, elevated blood pressure, compromised lung volume, high cholesterol and even breast cancer are also more likely to develop in offspring who are exposed to nutrition extremes in utero.  Even though we consider this to be a protected and insulated space, all babies still go through critical, sensitive windows of development, which have far-reaching consequences.

The foetus, far from being a silent observer, picks up cues about her environment and makes a series of adaptations in order to maximise her chances of immediate survival following birth and later if needed.

But I don’t want a skinny baby!

Pregnancy nutrition, overall health, and placental sufficiency during this developmental window can all contribute to the offspring’s health in later life; particularly when exposed to conditions of under or over nutrition, as her body makes permanent adjustments.  Even if, after she is born, there is plenty of good nutrition in the right amounts, her body is still primed to store energy and retain fat.  This applies equally for babies of mothers who don’t eat enough as those who eat too much.

Underweight babies tend to play ‘catch up’ when it comes to gaining weight after birth, saving weight for a rainy day – even if for the majority this is never required due to the abundance of food, particularly in our Western diets.  Babies exposed to too much nutrition lay down more adipose (fat) cells, which are with them for life. And all of this happens before she may have even taken her first breath.

The effects of this fat conservation don’t  stop at one generation either, but can have long lasting, intergenerational effects. The old saying “you are what you eat” has now been discarded with the more accurate, “You are what your grandmother ate”.

It’s always my fault!

Before you start feeling that this is another thing to add to your basket of guilt as a mother, your partner needs to share some of the responsibility.  There is also a paternal line of transmission in all of this; because men who are obese tend to have lower sperm counts overall as well as an increased risk of DNA damage to their sperm. This contributes to the vulnerability of their offspring becoming overweight as well.

It seems that even before conception a mother’s dietary intake as well as stress and environmental factors all play a role in influencing her offspring’s pattern of weight gain. The Body Mass Index (BMI), whilst not without its critics, is still a useful universal tool for identifying those at metabolic risk. Women who, pre-conception, are already within the overweight or obese range have more cause for concern.

A BMI of between 18.5 to 24.9 indicates a healthy weight range for young and middle-aged adults – (check  BMI). There are clear guidelines for what constitutes optimal weight gain during pregnancy and it’s worthwhile checking tools such as this  Pregnancy BMI. If knowledge is power, then sticking within a healthy weight range will have a direct effect on the familial patterns we are likely to see in years to come.

What we know to be true

• Breastfed babies gain weight in a different pattern to formula fed babies.
• The longer the duration of breastfeeding, the lower the concentration of body fat in babies.
• Breastfed babies self regulate their intake of milk but bottle fed babies have this done for them.
• Healthy, well babies are capable of knowing when they have had enough milk.  Parents and caregivers need to be sensitive to the cues and signals babies give when they want to stop feeding.
• Breast milk contains Leptin but formula does not. Leptin is a signalling hormone which tells our brain when we are full and to stop eating (or feeding).
• ‘Fat’ babies are not healthy babies. Nor will they be healthy adults.
• Sleep, nutrition and exercise are all ways in which humans modify the amount of energy their body retains.
• There is a higher concentration of protein in formula milk than breast milk.
• Consuming high energy (fat and protein) foods between nine and 24 months increases the risk of childhood obesity.
• High protein intake at two years increases the risk of childhood obesity.
• Children who are overfed between six and nine months lay down more fat cells.  This means they gain more weight even if they are fed the same number of kilojoules as babies in a healthy weight range.
• Low fat diets can increase the risk of children becoming overweight.
• Choline, folic acid and glycine and Vitamin D supplements may have beneficial effects on the children of mothers whose nutrition is poor. But a ‘one size fits all’ approach has not been proven.