In reply to erc1:
Hi all.
This is a very personal and interesting subject I am researching at the moment. The more understand (medically) about pregancy, the more complex it becomes, and every pregancy tends to be quite unique on the maternal side.
As other replies have stated, at the start of the first Trimester, you may not even know you are pregnant, although pregnacy tests these days have a very high sensitivity rate, but once the hormones "kick in" you may not feel like climbing.
During the second trimester, the foetus is well cushioned by the mother and and an adequate supply of amniotic fluid/liquor (ask at your 20week scan)
In the third trimester, the foetus is "cooked" by 36weeks, and then is laying down foetal fat ready for the first few days outside the womb.
The research I am reviewing is about high impact foetal injuries ie seatbelt injuries from rapid deceleration, but there, at present,is no correlation between, gestational age of foetus, speed of impact, and even placental site, and these deceleration forces are far higher,than say a 10m leader fall.
I dont want to sound alarmest but placental abruption (separation of the placenta from the womb)although rare, less than 2% of pregnacies can just occur spontaneously.
As was quoted earlier Obstetricians, Gp's and Midwives tend not to understand climbing and so will tell the mother not to climb, however they will accept the risk that the same mother will get into a car, and feel safe with a seatbelt.
This is an extremely brief overview,and pregnancy is very immotive and personal to the prospective parents.(Thats my disclaimer).
However, if anyone requires any advice, please contact me, and I will endeavour to give you helpful information to take to your maternity unit.
Hope that was informative.
Cheers
Nick