What do you mean by “natural birth laying down”. Indeed natural birth can happen in any position that woman would chose to birth. However if you mean that Lithotomy Position = natural, it would be a misconception. Laying on the back for giving birth per se is not natural or normal in itself. It can happen and did happened occasionally for natural birth, particularly as one of the manipulation techniques in case of shoulder distortia, when it is done as one of the transitional positions, proceeded with some other position after that. And in a few rare cases, certain positioning of the baby leads mommy to chose lithotomy position, which is normal – to follow your body urges during birth.
But you need to be careful to not just “chose position” even before the labor, just because that is the only thing the doctor does, etc. That would be far from natural, and it can pose undue pain and complications. Remember, you would want to support mommy in following her body and baby’s needs and be as non-intrusive as possible, then she would have the birth that she meant to have and it would go the best way!
I thought, may be just a brief information on “laying on the back” lithotomy position can be a help, so you can have the information to work with:
The lithotomy position has been widely used by obstetricians as it allows easiest access to the mother, not necessary for mother’s or baby’s benefits or safety. This position is not based in evidence. It comes with a multitude of poor factors, including narrowing of the pelvic outlet, placing pressure on the tailbone, restricting the mother’s movement, placing undue stress on her perineum increasing the risk of tearing, working against gravity, increasing discomfort, lengthening the pushing stage, increasing the risk of a fetal malpresentation, and effectively making the mother push uphill against gravity.
If a mother is placed in this position during her labour, it compresses the main blood vessels including the vena cava, which limits the blood flow to the baby and places it at greater risk of fetal distress. That is why many mommies who are pressured to labor in that position strapped to various monitoring devices, end up with fetal distress and subsequent C-section. Lower rates of blood flow also causes more mothers and babies to die unnecessarily during childbirth.
Roberto Caldeyro-Barcia, past president of the International Federation of Obstetricians and Gynecologists, summed up it quite nicely in his statement, “Except for being hanged by the feet, the supine position is the worst conceivable position for labor and delivery”.
Use of the lithotomy position has declined in all industrialized nations with one exception. Yep, you guessed it - the United States.
So, what can you do? How can you avoid being yet another statistic who is forced into this unnatural birth position?
First of all, choose your care provider wisely. Take the interview process seriously. You must ask the tough questions and be prepared to keep searching until you find a care provider who is more interested in providing evidence-based care than in sticking to their agenda.
You must also be sure to write a birth plan stating your preferences for pushing. Remember, if you give birth in a hospital, you not only have to deal with the doctor’s practices, but also be prepared that the nursing staff may not be well-educated in using effective birth positions. Choose midwife, they are highly trained to manage natural birth!!!gn
In most cases, this lack of evidence-based care is due to ignorance, not malice. Physicians are simply practicing what they have been taught. Their actions in promoting the lithotomy position are the result of a broken maternity care system that fails to truly educate its students.


Here are some references:
REFERENCES
Seehusen Dean A. et al, Improving women’s experience during speculum examinations at routine gynaecological visits: randomised clinical trial British Medical Journal. 2006;333:171 (22 July), doi:10.1136/bmj.38888.588519.55
Anema J. G. ; A. F. Morey, J. W. McAninch, L. A. Mario and H. Wessells Complications related to the high lithotomy position during urethral reconstruction The Journal of Urology (J. urol.) 2000, vol. 164, no2, pp. 360-363 (42 ref.) ISSN 0022-5347.
Cohen, Stephen A., MD and W. Glenn Hurt, MD Compartment Syndrome Associated with Lithotomy Position and Intermittent Compression Stockings Obstetrics & Gynecology, 2001;97:832-833.
Johanson, Richard, Mary Newburn, and Alison Macfarlane Has the medicalisation of childbirth gone too far? British Medical Journal 2002;324:892-895, published 13 April 2002
Bachmann, Gloria, M.D. 2001 The Importance of Obtaining a Sexual History. UMDNJ Robert Wood Johnson Medical School New Brunswick, New Jersey.
Gupta JK, Hofmeyr GJ, Smyth R. Position in the second stage of labour for women without epidural anaesthesia. Cochrane Database of Systematic Reviews 2004, Issue 1. Art. No.: CD002006. DOI: 10.1002/14651858.CD002006.pub2.
Hunter S, Hofmeyr GJ, Kulier R. Hands and knees posture in late pregnancy or labour for fetal malposition (lateral or posterior). Cochrane Database of Systematic Reviews 2007, Issue 4. Art. No.: CD001063. DOI: 10.1002/14651858.CD001063.pub3.