Dear friend, your concerns or fears are misplaced as a side effect of maternity is neither amnesia nor dementia. Yes, maternity brings hormonal changes in women, but there is no medical evidence that shows that after delivering a child, women start forgetting everything.
Issues in Small Companies
The problem that you have mentioned could happen in small companies or unbranded companies. However, branded companies generally do not resort to firing women employees. Their removal is more because small companies arrange for the woman's replacement. Reinstatement of the woman who proceeded on maternity leave may not be possible; hence, the employers pretend that post-delivery, a woman's memory goes blank!
Importance of Staying Updated During Maternity Break
Yes, a maternity break may not last just for 26 weeks for which women are legally allowed to avail of maternity leave. Few women may extend it and take a break for 2-3 years. However, during this period, as the infant starts growing, it is in the interest of their career to keep themselves updated about the changes, especially statutory changes related to their profession. Women may spare some time of their day to read material related to their profession. For example, if a woman HR professional is on a maternity break, she may even visit this forum and go through the discussions that occur here. This is also one of the ways of keeping oneself updated. However, if some women spend time on social media rather than intellectual enhancement, then they are responsible for wasting their time, and employers cannot be blamed if such women forget everything about their jobs!
Thanks,
Dinesh Divekar