Here is a wonderful video showing what happens from conception to birth in just 4 minutes.
Don't worry, it's all computer animation and no babies were harmed in the process!
What is interesting for an osteopath is to notice how early all the important structures are formed (within the first 12 weeks) and we are mostly just getting larger after that.
Although I've always found it fascinating that a baby doesn't have a heart beat until the fifth week of development and yet there is blood circulation well before this. Yes the placenta helps via the maternal heartbeat but there is a drawing effect from the tissues that need to nutrient to form as well. One way function dictates structure, a concept osteopaths are very interested in.
Also, look at how the baby has to twist one way and reverse to get out at birth. This may result in birth strains, especially if the labour is a long one. If you are interested in the journey from conception to birth, look out for this really good 3 part documentary Countdown to Life available on ABC iView.