Even as many new mommies worry about the problem seeing it as a sign of weakness, experts have now assured that mumnesia is a medical condition. Researchers have found the key factors which cause memory failures, including hormonal changes, tiredness, and the stress of having to look after a new child. Terming it a short-term problem, which lasts only for a few months, researchers suggest that women should not worry too much about the phenomenon.
The post-natal forgetfulness can be put down to four main factors -- Priorities, pain, hormones, and fatigue.
''New mothers are dedicated to serving that little infant, determined to keep him or her alive no matter what. That's their number one priority above all else,'' experts suggest.
Consequently less important matters get forgotten, or at least put into a less active area of the brain.
Secondly, forgetfulness is part of women's defence mechanism after the pain and rigours of childbirth, Dr Sharon Phelan said, explaining if the memories didn't fade, we would never have sex again.
Thirdly, women's oestrogen levels plunge from incredibly high in late pregnancy to virtually non-existent after childbirth. And while oestrogen plays a key role in fertility, it also acts as a neurotransmitter, sending signals in the brain.
Finally, new mothers get tired as they tend to lose up to 700 hours of sleep, equivalent to two hours a night, in their baby's first year.
''Fatigue is a killer issue for memory,'' MIT neuroscience professor John Gabrieli said.