Chemicals found in cigarette smoke have been shown to damage foetal liver cells, but they affect boys and girls differently.
Major Comments Spark SNP Row
A spat has erupted between former Tory prime minister Sir John Major and Scotland's First Minister over the role the SNP could play in a future UK government.
Nicola Sturgeon branded Sir John an "affront to democracy" for what she claimed was a "silly, over the top" intervention in the campaign.
With the Conservatives and Labour both vying to win the race to Downing Street, Sir John, the last Tory prime minister to have an overall majority, claimed that the rise of the SNP represents "a real and present danger" to the future of Britain.
A minority Labour government propped up by Ms Sturgeon's party would be a "recipe for mayhem", he claimed, with Ed Miliband subjected to "a daily dose of political blackmail" from Scottish nationalists who would push to break up the United Kingdon.
"They will ask for the impossible and create merry hell if it is denied," the former prime minister warned.
"The nightmare of a broken United Kingdom has not gone away. The separation debate is not over. The SNP is determined to prise apart the United Kingdom."
But Ms Sturgeon insisted the comments were "actually an affront to democracy".
Mr Miliband accused the Conservatives and David Cameron of "talking up" the SNP in the hope that the nationalists will win seats from Labour north of the border and allow him to "crawl back" into 10 Downing Street.
Ms Sturgeon, who addressed the Scottish Trades Union Congress in Ayr, said that SNP MPs at Westminster could "vigorously and loudly" support a future Labour government in some areas.
The SNP leader added: "John Major's comments are silly, over the top and frankly they don't show him in a particularly good light.
"I want the SNP to go to Westminster to make Scotland's voice heard and also to be a voice for better politics, for the kind of politics that stands in opposition to Tory policies of austerity and undermining public services and pushing more people into poverty.
"I can understand why that message of standing up for ordinary people not just in Scotland but across the UK might offend John Major as an ex-Tory prime minister, but I think it's a message that will continue to win support right across Scotland."
Scottish Labour leader Jim Murphy accused both Mr Cameron and Sir John over their attacks on the SNP.
Mr Murphy, who was campaigning in Glasgow, said: "This is tawdry politics by not just one but two Tory prime ministers.
"John Major and David Cameron have given up on the Scottish Conservative Party and are giving their all to the SNP.
"The Tory party no longer has its own independent campaign in Scotland but has become an active campaigner for the SNP.
"The Tories are making it clear by their words and their deeds today that David Cameron can only be saved by Scotland voting SNP."
He added: "We are clear that the way to guarantee the end of the Tory government is to vote Labour rather than to gamble on the messy outcomes of a hung parliament."
Liberal Democrat Leader Nick Clegg said the Tories had only got it half right.
Launching his party's countryside charter in Cornwall, he said: "I think the greatest two threats to the future stability of our country is either a Labour-SNP alliance on the left or a right-wing alliance between the Conservative party, Nigel Farage and the DUP."
The SNP leader is hoping to build on her party's 2015 success of winning a record 56 out of 59 Scottish Westminster seats.
The powers include responsibility for Ill Health and Disability Benefits, Carers Allowance, Cold Weather Payments and Winter Fuel Payments.
The update in the high-profile litigation comes after a judge overseeing the action granted a series of adjournments to allow settlement discussions between investors and the bank.
Most Viewed Pictures On Heart
Recently Played Tracks
To listen live, choose your preferred station:
Now playing: The best feel good music
Now playing: The best feel good music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart Scotland- East.