It was recently Mothering Sunday, the day devoted to celebrating our Mums and everything they have done for us. From psychologists to geneticists, there are a broad range of scientists focused on researching pregnancy, birth and motherhood. ‘Maternal bond’ is the term used to describe the special relationship between mother and child. So what is this bond? Is it a love that can’t be explained or is there some physical cause behind it?
The mechanisms responsible for the formation of the maternal bond are widely disputed. While it is thought that hormones and physical changes within the mother may play a key role, it is not known to what extent these are responsible. It is also unknown whether it may be possible to replicate these changes in order to help those struggling to bond with their babies.
The hormone oxytocin is often referred to as ‘the bonding hormone’. It is known to play an important role in childbirth and lactation, but studies also show a strong link between levels of oxytocin during pregnancy and the ease with which the mother bonds with her child. Mothers also receive a large influx of other hormones during pregnancy, all of which help to prepare her body for the baby. It is thought that this change in hormonal levels may be responsible for changes within the brain, and studies have found that the brain may grow during childbirth. Brain scans before and after the birth show a growth in the volume of grey matter in areas of the brain associated with emotions, reasoning and judgement, with largest increases observed in mothers who were more enthusiastic about the birth of their child. It is thought that changes to the brain may help build a mother’s intuition and contribute towards instincts associated with care. Scientists are, however, still confused about the order of cause and effect. They are unsure whether changes in the brain occur in order to ensure the correct emotional response, or whether the huge emotional response to becoming a mother triggers the changes within the brain.
It has long been thought that the labour and birth itself could play crucial roles in the formation of the maternal bond. The pregnancy period can also be critical, including the emotional environment and stresses experienced by the mother. Breastfeeding may also be important in the bond formation; with so many factors, it is hard to isolate which physical factors have the most impact.
A surprisingly large number of mothers struggle to bond with their babies or cope with their arrival. It is estimated that one in three mothers suffer from post natal depression. Having waited months expectantly for their babies to arrive, they are left feeling guilty when they fail to bond, so finding the scientific explanation and physical reasons to explain why they may be experiencing problems could be a huge reassurance for these mothers as well as opening up the door to possible research into treatments.
Not only can the mother’s emotional state be a consequence of physical mechanisms, it can also have a physical impact on her child. Recent studies show that the fetus may be able to sense a mother’s psychological state and may be directly affected by it. In fact, there are an increasing number of physically observable changes due to neglect that have been discovered. For example if the mother is malnourished during pregnancy the child may be better at coping with food scarcity, but is likely to end up obese on a normal diet.
Recent studies also show that the brains of children who received the largest amount of parental attention in early childhood have the largest hippocampi. The hippocampus is a key area of the brain involved in memory, response and learning. These findings highlight the importance of parental attention and input.
For many mothers there is one defining moment that suddenly marks the creation of an unbreakable bond, whether it is the first time the child kicks in the womb or the moment they first grip their finger. This feeling however is not reserved just to biological mothers; adoptive parents often feel the same familial connection. Some people therefore believe that there is little point trying to quantify the connection in terms of physical hormones and differences. But for those mothers who are struggling to bond with their children and are left feeling inadequate and for those children who are not receiving the attention they require, finding a way to address hormone balances and discovering where the problems lie could make a huge difference.