Legalities aside. I've always wondered why a business would employ someone who is pregnant just to give them maternity leave for three months when they wouldn't even have completed their probation.
What is the logic behind it?
If I have 5 roughly equal candidates and I know one will need to be covered (and paid) for 3 months shortly after arrival, I still have 4 other candidates. The difference with existing staff is I have a proven, trained and valuable employee by then.
If I'm advertising a position for a cook, cleaner, data entry, clerk, or almost ANY position in the 99% of the job range niche, I'll have plenty of people to choose from, I have more difficulty filtering them out than finding them. Logically to me (in the absence of convincing answers) pregnancy would be a filter. I want the food cooked every day, the office cleaned, the data entered, the filing done etc,. not a moon trajectory calculated.
So if I knew a lady is pregnant I'd cross her off the list. I cannot think of a single reason not to. If she started work and I found out that she hadn't disclosed she was pregnant beforehand she would be lucky to make it through her probation period. I'd get rid of her then if not sooner.
Different story if it's an existing staff member who gets pregnant of course. One of my ladies has had 4 kids and another on the way, I have no issue with paying maternity leave and my contribution when the office passes the hat will at least double everyone elses combined.
Importantly because I know when she is due, I have already organised for her tasks to be covered when the time comes. If I didn't know then not only would I be paying a new hire but I'd also have to pay someone else to cover. Two people receiving pay for one job with no guarantee that the first will be any good at the job or even that the proven mercenary person will even return after 3 months. Makes more sense to give the job full time to the second person from the outset unless I'm missing something.
SUMMARY:- All else being equal what logical reason would a business have to hire a pregnant lady instead of discriminate against her being hired based on her pregnancy. If she hid her pregnancy to land the job, what logical reason would they have for not seeing that as a sign of self-serving dishonesty.