Population dynamics

• Population dynamics is an area of the biological sciences that focuses on alterations in the number and age distribution of populations
• The study of population dynamics examines how a species' numbers fluctuate over time at a specific place
• Each species' population has a distinct physical distribution that varies over time and space according to how well the species has fared in that specific habitat
• A population is made up of individuals belonging to the same species that have settled in a certain location for a predetermined amount of time
• The study of changes in population size and structure over time
• The determinants of population growth are the number of births, deaths, and the total migration into and out of the area
• Types of population growth:

  • Natural or reproductive growth: balance between births and deaths
  • Total growth: balance between births, deaths, and migration
• Population dynamics involves issues such as population size, growth rate per annum, distribution, death rate, migration, etc.
• These provide information needed for the formulation and development of population policies
• Population policies are statements of important goals on the size, growth, composition, and distribution of the population of a country accompanied by specific means of achieving them
• Factors affecting population growth:

  • Disease across borders
  • Labour drain/cheap labour
  • Brain drain syndrome
  • Socioeconomic effects
• Effects of migration:

  • Security/political stability
  • Wealth
  • Employment
  • Educational opportunities
  • Standard of living (social amenities)
  • Natural disaster/war
  • Medical facilities/medical tourism
• Three general profiles of age-sex composition:

  • Expansive: high fertility population with a large proportion of people in the younger ages
  • Constrictive: declining fertility with a relatively smaller proportion in the younger ages
  • Near stationary: zero growth or decreasing population with roughly equal numbers of people in all ages tapering off gradually at the older ages
• Population pyramids:

  • Expansive: high fertility population with a large proportion of people in the younger ages
  • Constrictive: lower numbers or percentages of younger people
  • Near stationary: stability of vital rates, rectangular shape, equal proportions of the population in each age group
• Definition of family planning:

  • Voluntary way of thinking and living based on knowledge, attitude, and responsible decision by individuals and couples to promote the health and welfare of the family group and contribute to the social development of a country
• Brief history of family planning:

  • Desire to control reproduction is as old as humanity
  • Margaret Sanger was a pioneer in family planning in the early 1900s
  • Family planning started in Britain in 1930
  • Modern methods introduced due to problems like abandoned children and criminal abortion
• Family planning counseling:

  • Process in a one-to-one relationship between the counselor and the client
  • Goal is to provide adequate information for informed choices about contraception and reproductive health
  • Effective counseling method using GATHER: Greet, Ask, Tell, Help, Explain, Repeat
• Ideal method of family planning:

  • Effective, reversible, minimal side effects, cheap, accessible, acceptable to both partners, easy to use
• Male methods of family planning:

  • Oral contraception
  • Immunological contraception
  • Barrier methods like condoms
  • Permanent method like vasectomy
• Female methods of family planning:

  • Natural methods, abstinence, withdrawal, rhythm method, Billings method, Lactational Amenorrhea Method (LAM)
  • Barrier methods like female condoms, cervical caps, oral contraceptive techniques
• Risks of oral contraceptive pills:

  • Thromboembolism
  • Myocardial infarction and stroke
  • Hypertension
• Intrauterine devices (IUD):

  • Types include Polythene and copper, Lippes-loop, Saf-T-Coil, Copper-7, Novagard, Copper T, Multiload
• Emergency contraception:

  • Combined O&P (high dose)
  • Progesterone only (0.75mg levonorgestrel)
  • Antiprogestesterone (Mifepristone 600mg)
  • IUD insertion
• Permanent methods of family planning:

  • Bilateral Tubal Ligation (BTL)
  • Hysterectomy