A thermally stable microporous breathable film is provided comprising at least 35% filler, by weight of the filled-film, and a thermoplastic polymer blend of a first polyethylene polymer and a second polyethylene polymer. The first polyethylene polymer comprises 30%-70% by weight of the polymer blend and can have a density between about 0.86 g/cm<SUP>3 </SUP>and 0.89 g/cm<SUP>3 </SUP>and the second polyethylene polymer can have a density between about 0.90 g/cm<SUP>3 </SUP>and 0.92 g/cm<SUP>3</SUP>. The filled-film can be uniaxially or biaxially oriented to form a microporous film and/or film laminate having good body conformance and which retains a high WVTR at 37° C. and above.