London, March 6 : Scientists have provided relief to thousands of new mums worldwide, by confirming that mumnesia or loss of memory on the arrival of a baby, is in fact a medical condition.
Mumnesia is experienced by many new mothers who usually notice small lapses of memory such as struggling with names, misplacing things or forgetting what they are looking for following the delivery of their babies.
For years, women have fretted over the condition, seeing it as a sign of weakness and an indication of future problems.
But now, neuroscientists and psychiatrists have reported that rather than being just an old wives' tale, the phenomenon of "mumnesia" is based on medical fact.
Experts note that a combination of fatigue, hormonal changes and stress can all contribute to a loss of memory.
Louann Brizendine, a neuro- psychiatrist, said the condition could be blamed partially on new mothers focusing on the welfare of their baby to the exclusion of other things.
"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," the Telegraph quoted her, as saying.
"Consequently less important matters get forgotten, or at least put into a less active area of the brain," she added.
Dr Sharon Phelan, a gynaecologist at the New Mexico School of Medicine, said that forgetfulness is part of women's defence mechanism after the pain and rigours of childbirth.
"If our memories didn't fade, we would never have sex again," Dr Phelan said.
Also, women's oestrogen levels could play a part in loss of memory.
Oestrogen levels fall from extremely 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, fatigue due to loss of sleep could also be another significant factor.
The researchers estimated that a woman could lose up to 700 hours of sleep, equivalent to two hours a night, in her baby's first year. Thus, the resultant fatigue can have a huge impact on memory.
Prof John Gabrieli, a neuroscientist at the Massachusetts Institute of Technology, said: "Studies suggest people may replay events of the day in their minds while they sleep."
"When people don't sleep, or if their sleep is fragmented, events of the day may not be consolidated into long-term memories," he added.