even though an employer's sickness policy may provide for dismissal after a set period of absence, it is unlawful sex discrimination to implement that policy to dismiss a female worker during her pregnancy for absence caused by a pregnancy-related illness - but reducing her pay or taking other steps short of dismissal pursuant to a sickness policy which applies equally to both sexes may be lawful.
See also notes at Pregnancy/dismissal or detriment for reason connected with and/or Maternity/maternity leave/illness delaying return to work and/or Illness, sickness and accidents/general