Women now take maternity rights for granted, and employers, supposedly, accept them as a fact of life. Yet a steady trickle of disputes passing through industrial tribunals suggests that the law is still being flouted.
In a case being heard in Southampton this week, Nicola Macleod, a stable groom, is claiming that her former employers, a senior judge and his wife, reduced her wages when she became pregnant and then dismissed her. They, for their part, say that there was less work for Ms Macleod to do because they had sold some horses, and also that they paid her redundancy.
This particular case has yet to be resolved. But in general terms it seems baffling that, more than 20 years after the enactment of legislation on statutory maternity rights, there should still be any uncertainty in this area.
In fact, say equal opportunity campaigners, the law is riddled with loopholes and obscured by grey areas. Only last month, Lord Justice Browne-Wilkinson, who sits on the Employment Appeals Tribunal, described it as being "of inordinate complexity, exceeding the worst excesses of a taxing statute".
On the surface, the legal situation seems clear. Pregnant women are entitled to return to the same job, at the same status and salary, after a minimum of 14 weeks maternity leave, irrespective of length of service. Up to 40 weeks may be taken if a woman has been employed for 27 months by the time of the birth.
Statutory maternity pay is set at 90 per cent of average salary for six weeks, and a flat rate of pounds 55.70 for a further 12 weeks.
But the "right to return" provision, according to Joanna Wade, legal officer of the Maternity Alliance, is a "complete minefield".
If a woman takes off more than 14 weeks, for instance, she need only be reinstated in a "substantially similar" job - a vague term open to wide interpretation.
"An awful lot of women are effectively demoted," says Ms Wade. "Secretaries, for instance, end up back at work as filing clerks."
Moreover, if companies with less than five workers can show that it was not "feasible" (another vague term) to re-employ a woman in any capacity, they need not take her back at all.
The Maternity Alliance says widespread ignorance means that many women bow to pressure from employers to return to work earlier than they are legally obliged. Among other things, it is calling for minimum statutory leave to be extended to 18 weeks, the same period for which maternity pay is available.
Its advice to pregnant women is to get a copy of their company's maternity policy, if it exists, and to acquaint themselves with their rights through the leaflets put out by the various support groups.
Employers, too, would do well to read up on the law. In these supposedly enlightened times, some still exploit maternity leave to dismiss an already unpopular female worker.
It is a move likely to cost them dear at a tribunal.