The CSeries has had a long and difficult birth, but should enter service in 2014.
"We need to have predictors - when it will be a difficult birth, when a woman might go into early labour, for example, " Prof Wray says.
Male foetuses put much more strain on the mother's body, they are more difficult to give birth to, and they are much more likely to take risks.
Eventually, Carolyn became pregnant with the couple's third child, resulting in another difficult pregnancy and premature birth.
Trying to raise birth rates is difficult because people's fertility does not seem to respond much to fiscal incentives.
When former President Ronald Reagan visited his birthplace in Tampico, Illinois on May 10, 1992, this tender-hearted, consummate gentleman, fast-fading with enveloping Alzheimers, wept, said curator Joan Johnson, as he laid eyes on the bed, where his mother Nelle had labored for many difficult hours, before giving birth to him on February 6, 1911.
And advocates say transgender people can find it difficult to change gender on their birth certificates because many states require proof of gender treatment surgery.
"This was the most difficult bill to bring from conception to birth that I can imagine being involved with, " one of the bill's primary co-sponsors, Republican Sen.
Even if the turbulence passes, this week's events have made the birth of a grand coalition more difficult.
It is difficult to believe that the accident of his birth place and his choice of the UK as home are the reasons for what is widely seen as prevarication and delay in the appointment.
And when they made it through the most difficult time which may have determined the difference between the birth or extinction of a nation, they gave thanks.
However, the main demographic problem facing Europe is a declining birth rate, which is threatening to make it difficult to pay for pensions for future generations.
Women who give birth in hospitals during the day may be more likely to have a difficult labour, researchers suggest.
Reagan, whose life spanned from the pre-Federal Reserve world at the time of his birth to the era of computer-driven financial innovation during his presidency, appreciated how difficult it was to achieve lasting monetary stability because he had seen the ups and downs of most of the twentieth century.
应用推荐