Next time your baby wakes you up at 4am screaming, don’t blame his barely damp nappy or pretty full tummy – blame evolution.
According to new research, the reason why little ones wake up so often in the night is because they are trying to delay you from having another baby so close in age to them.
A research team from Harvard University has posited that because having children close together was historically linked to higher mortality rates, humans have evolved a way to prevent their parents from producing more little ones while they are still totally dependent and vulnerable.
‘Maternal fatigue can be seen as an integral part of an infant’s strategy to extend the inter-birth interval’
Lead author Professor David Haigh pointed out that babies aged six months and over are more likely to wake repeatedly in the night than newborns – and that happens to coincide with the time mums start to become fertile once again (if they are exclusively breastfeeding, that is).
‘Natural selection will have preserved suckling and sleeping behaviours of infants that suppress ovarian function in mothers, because infants have benefited from delay of the next birth,’ he wrote in the Evolution, Medicine and Public Health journal.
‘Maternal fatigue can be seen as an integral part of an infant’s strategy to extend the inter-birth interval.
‘More frequent and more intense nursing, especially at night, is associated with prolonged infertility,’ he added.
While exclusive breastfeeding up to six months brings on a condition known as lactational amenorrhea – temporary postnatal infertility – it is wise to consider other forms of contraceptive if you are planning to resume your sex life a few weeks after giving birth.
What do you think of the study results?