probably the INTENSITY and LEVEL of pain is more or less the same - however, the kick is just one sharp shock pain and then over with...you are left to recover
but the childbirth, the pain is not only more or less constant it gets worse and worse over many hours, until it peaks every few minutes or so - AND THEN... AFTER all that, you have to try to force a grapefruit out of an orifice that has previous only had the width of a cucumber anywhere near it. (the wide end if you are lucky...;o)
heres the scenario -
9pm - kick in the nads
10pm - another kick in the nads
11pm - another nadkick
12am - another nadkick
1am-another nadkick
2am-another nadkick
3am-another nadkick
3.30am-another nadkick
4am-another nadkick
4.20am-another nadkick
4.40am-another nadkick
5am-another nadkick
5.10-another nadkick
5.20-another nadkick
5.25-another nadkick
5.30-another nadkick
5.33-another nadkick
5.35-another nadkick
5.36-another nadkick
5.37-another nadkick
then, no rest to get over the above, oh no, then the 'pooing a basket ball' situation.
then your skin, about an inch or so just RIPS OPEN - imagine that little bit of skin under yout top lip - just being forced apart.
then once the baby is out, still no rest - out comes the placenta - more contarctions and pushing
then, you get a needle in there to sew you up and finally you can rest
then just a few weeks of feeling like you've gone few rounds with mike tyson, stinging, itching etc