I would be interested to know where you got that number from.
The 60%-80% number is commonly accepted, and available at many sites, including:
http://www.emedicine.com/emerg/topic6.htm
Where we read:
Many pregnancies are not viable, with an estimated loss of 50% before the first missed menstrual period. These pregnancies usually are not clinically recognized. Classic spontaneous abortion is defined as a clinically recognized (ie, by blood test, ultrasound) pregnancy loss before the 20th week of gestation. Spontaneous abortion occurs in an estimated 10-15% of pregnancies.
And, later:
Age and increased parity affect the risk of a miscarriage. Twelve percent of pregnancies terminate in miscarriage in women younger than 20 years; frequency increases to 26% in women older than 20 years.
So, about 60-65% of conceptions result in spontaneous abortion, rising to 76% for women over 20.
This, to say the least, presents something of a crisis for fundies.
I mean, how can you justify a loving god that cherishes all human life with the creation of a system that results in the 'murder' (as said fundies would have it) of up to 76% of all humans right off the bat?
Either a fetus does NOT have a soul from the moment of conception, and thus does not need the amount of protection under law, etc., that an adult receives. Or, it DOES, and 'god' has designed a woman's reproductive systems as a baby butchering factory. (I realize how awful that sounds, and I apologize in advance to any who are offended - but it DOES accurately describe the situation).