Yes, pregnant women are entitled to a maternity allowance, for which they apply either to the insurance institution they are insured (e.g. IKA) or to a social welfare office (Pronoia), if they are uninsured. The allowance lasts 17 weeks, 8 weeks before the birth and 9 weeks after the birth.
Source: www.dikaiologitika.gr, www.inegsee.gr