The book is an exploration of the empirical data from a Major Research Project sponsored by ICSSR, New Delhi (final report submitted in 2016). It deals with human fertility dynamics along with its paramount indicators – the duration of first birth interval, the duration of third birth interval and the phenomenon of third birth transition in Manipur, the easternmost Indian State internationally bordering with Myanmar. A concise introduction is firstly initiated with origin of the work, definitions of variables, objectives and research methodology and demographics of the study population followed by the review of previous works through factor-wise review system. The variations in fertility indicators between tribal and non-tribal women are explored along with the variations in current fertility according to various socio-economic, demographic and behavioural factors in isolation. A multiple regression analysis also identified the most contributing factors on the average fertility differentials. The effects of socio-demographic variables on the duration of first birth interval are also assessed by using survival analysis techniques and also the effects of elsewhere factors on the duration of third birth intervals. The Cox’s PH models examine the factors influencing the variations in the durations of third birth intervals. It also identified the effects of socio-demographic variables on one of the most serious demographic phenomenon of third birth transition utilizing binary logistic regression models. About the Author: N. Sharat Singh, M. Sc. (1989; Meerut University, U.P); Ph. D. (2002; Manipur University, Imphal) in Statistics is presently working as faculty member in the Department of Statistics, Dhanamanjuri University, Imphal. Having twenty-two years of teaching experience in government degree colleges of Manipur, he specializes for research in the field of Biostatistics with special interest in reproductive health. He has authored three reference books entitled “Determinants of Infant Mortality” in 2007 (co-author), “Dynamics of Women Reproductive Span” in 2015 and “Socio-Economic and Fertility Level of Chandel People in Manipur” in 2021 and also edited two books entitled “Understanding Multidisciplinary Research Works: A New Aspect” in 2016 and “Applications of Statistical Techniques in Social Data” in 2019. Having being published more than fifty original research articles in reputed journals, edited books and conference proceedings, he has completed two Major Research Projects under UGC (Delhi; 2011-2014) and ICSSR (Delhi; 2014-2016) and also completed two research projects under UGC, NERO in 2005-07 and 2008-10. He has guided four Ph. D. students (degrees awarded in 2013, 2014, 2016 and 2018). Presented more than thirty original research papers in national and international seminar/ conferences, he has also delivered more than twenty-five invited lectures/ talks on research methodology courses specifically on the applications of statistical tools in various data of socio-economic, demographic, biosocial, health, industry, engineering etc. He has also successfully convened more than eight seminars/ conferences/ workshops during the last decade. Mr. Singh has contributed his consultancy services to more than seventy-five research works leading to Ph. D. and Research Projects mostly dealing with social data. He is the life members of Indian Society for Probability and Statistics (ISPS) and Indian Association for the Study of Population (IASP). O. Tomba Singh, M. Sc. (1986; Aligarh Muslim University, U.P); Ph. D. (2014; University of Lucknow, U. P) in Statistics is Associate Professor in the Department of Statistics, Dhanamanjuri University, Imphal. He has more than thirty years of teaching experience in government degree colleges of Manipur specializing in design of experiment and various statistical methods. His research field of interest is women health.