Journal of Medical Sciences1682-44741812-5727Asian Network for Scientific Information10.3923/jms.2005.204.207Todorov AtanasovAtanas 3200553Using the relationship between length of pregnancy T(day), body mass M(g) and basal metabolism of mammals from type: T=7.5451 M0.2689 and T.P/M=Apr , where, P (kcal/day)-rate of metabolism, Apr(kcal/kg)-total metabolic energy of mother during pregnancy, per 1 kg body mass, a method for calculation the prolongation and reduction of pregnancy duration was proposed.]]>Lasiewski, R.C. and W.R. Dawson,1967691323Rahn, H., C.V. Paganelli and A. Ar,197592750765Brody, S., R.I. Procter and U.S. Ashworth,1934220140Atanasov, A.T.,20058915Atanasov, A.T. and B.D. Dimitrov,2002666571Alaily, A. and K. Carrol,197885518518Durning, J.,1987211311131Ueland, K. and J. Metcalfe,1975184141Naumov, N.P. and A.P. Kuzjakina,197161300Nielsen, K.S.,1984pp: 9-234pp: 9-234Atanasov, A.T.,20042004pp: 233238Maurice, B.,1962Brody, S.,1945Pages: 1023Pages: 1023Hytten, F.E.,19911991Hadgiev, A., A. Jarakov and N. Vasilev,1998pp: 58-68pp: 58-68Atanasov, A.T.,20042004pp: 333335Markov, G.,19802nd Edn.,pp: 1-200pp: 1-200