Forcing pregnant women who do not want a child of one sex or the other to give birth could harm both the baby and the mother's mental health, a leading doctors' union member has said.

Prof Wendy Savage, a voting member of the British Medical Association Council, also said women should have the right to terminate a pregnancy at any stage.

The comments by Prof Savage, a women's rights campaigner and retired obstetrician and gynaecologist, come after a proposal to decriminalise terminations passed the first hurdle in the House of Commons last week.

Her intervention is likely to spark a strong reaction from campaigners on both sides of the argument.

Prof Savage said sex-selective abortions were a "myth" and hit out at NHS hospitals which refused to disclose an unborn baby's sex.

Parents wanting to find out the sex of their baby can usually do so in a mid-term scan at between 18 to 21 weeks, but some hospitals have a policy of not telling, according to the NHS Choices website.