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The Human Population: Patterns, Processes, and Problematics Lecture #8: How we control Fertility Paul Sutton psutton@du.edu Department of Geography University of Denver
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The “How’s” Of Fertility Control Revisited
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Real Differences in Fertility between population result from differences in these ‘Core 4’ 1) Age at marriage 2) Use / Non-use of Contraceptives 3) Incidence of abortion 4) Involuntary infecundity
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Involuntary Infecundity Countries where breast feeding is common have higher fertility rates than countries where breast feeding is uncommon. WHY? And what is paradoxical about that?
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Understanding Fertility focuses on Female behavior and Issues and virtually ignores men… “If a woman never has intercourse she will never have a baby. A man will never have a baby no matter what he does.”
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Intercourse Variables 1)Age at entry into sexual union 2)Permanent Celibacy 3)Time between Unions 4)Voluntary Abstinence 5)Involuntary Abstinence 6)Coital frequency
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Age at entry into Sexual Union Permanent Virginity is rare; however, the longer one maintains it the lower their fertility will be In Pre 1960 U.S. & Canada –Age at Marriage = Age of sexual union Not True anymore –1/3 to ½ of women 15-17 have had sex Age at first marriage rising in the United States Teen sex: Blacks > Hispanics > Whites In Niger & Bangladesh ½ of women have children before they reach the age of 18
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Permanent Celibacy Those women who never marry Permanent Celibacy NOT popular (never > 10% oustside Europe) Highest Ever? Ireland 1971 18% of women 40-44 never married Never Married not Same as Childless
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Time between Unions Married people have more ‘viable’ sex than unmarried people Women who have been divorced have lower fertility than women who have married but never divorced. (duh?) Couples in ‘long distance’ relationships have lower fertility. Married couples (in U.S.) have sex 2-3 times/week
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Voluntary Abstinence Not Popular – But: historically important in Europe & England Uncommon now except after birth of a child (doesn’t matter much due to post-partem amenorhea) Post-Partem sex is taboo in some places for up to two years
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Wacky Attempts at ‘Voluntary Abstinence’ Atate al Catre! – “Tie yourself to the bedpost” “Through a combination of coitus interuptus and abstention, most villagers manage to keep births down. Though they openly complain about the frustrations which these methods entail, they are willing to make the sacrifice in order to assure their ability to provide their children the best possible opportunities. Those husbands who cannot exercise control are seen as somewhat animalistic.” 37 year old woman with 5 kids in Mexico for sake of her existing kids wants no more. Husband says no contraceptives. She says “No sex” (man goes elsewhere and spreads disease) Dear Abby’s Large Dog letter
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Involuntary Abstinence Jobs: Sales, transportation, separate vacations Medical: Hospitalization, Disease, etc. Migration: Male labor too far away from wives Not Common Not Popular
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Coital Frequency aka “How often do you have sex? More sex > More Pregnancy (duh?!) Too much sex for men reduces fecundity for the short term 3 times per week; 51% pregnant in 6 months 1 time per week: 32% pregnant in 6 months Marriage, Age, and Sex –1950 Married Women 21-25 twice as much sex as women aged 41-45 –2002 Married Women 21-25 have no more sex than women 41-45 Why? Changing Social Mores & Contraception
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The “Right Time” to conceive
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Conception Variables 1) Breast Feeding 2) Contraception –Female Barrier Methods –Female Chemical Methods –Female Natural Methods –Male Methods Condom Withdrawl –Couple Methods –Traditional Methods –Voluntary Infecundity
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Breast Feeding Breast Feeding prolongs post-partem amenorhea and suppresses ovulation –2 months for women who don’t –10-18 months for women who do Strange contradiction –Modernization reduces Breast Feeding –Breast Feeding declines as fertility declines Wet Nurses and Working Women –1800’s in France Infant Mortality 250/1000
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The Nestle Controversy Concern women in LDCs switching to Bottle Increase fertility, Infant and Maternal Mortality Watered down formula, bacteria in bottles etc. UNICEF and WHO 1981 voluntary limits on ads & Marketing of Formula Corporate and U.S. opposition 1991 Swiss Firm Nestle limited Free Formula 1991 Study showed ‘Marketing’ not too important in Breast vs. Bottle decision
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The ‘La Leche’ League Movement back to breast feeding are led by better educated women Irony? The very same women whose fertility is apt to be kept low by deliberate use of contraceptives? 1991 81% of college degreed women breast fed 1991 less than 50% of women w/ H.S. or less did AIDS twist 15% chance of giving AIDS to child you breast feed
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Contraception
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Physical Methods (for gory details see the Weeks Text) Diaphragm not very effective without spermicide Female Condom popular for protection from AIDS IUD (1 st one in 1909) –Great hope of family planners for preventing pop explosion –Fuzzy on how it works –String is a “Ladder for Bacteria” –2/3 of world’s IUD users in China
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Female Chemical Method: The Pill Synthetic Hormones that suppress ovulation by keeping estrogen levels high Ovaries do not release Egg Progestin in Pill makes cervical mucous “hostile” to egg implantation Almost 100% effective (unless you forget to take it)
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Types of “The Pill” Progestin & Estrogen 21 days on 7 days off Tri-Phasic Pill –Trys to match natural cycle (not as effective) “Mini-Pill” (progestin only) –Commonly used by breast feeding mothers
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Controversy over “The Pill” Most popular non-surgical method of contraception in the United States Problems with side effects Temporary: Nausea, breast tenderness, spotting Permanent (?) – aggravates the following: –High blood pressure –Blood clotting –Diabetes –Migraine Headaches –Breast Cancer ??? May increase life expectancy by 4 days
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Controversy over “The Pill” continued… “The Pill” is far and away the most widely studied drug in the history of pharmaceuticals “The point that these opponents of the Pill really miss is that the Pill as well as all other methods of fertility control should be available for any woman who is willing and able to use them given her particular circumstances….The reality is that for many women throughout the world, the Pill is the best contraceptive method currently available” (Carl Djerassi inventor) Conclusion: Make an informed decision based on best information
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Implants and Injections NORPLANT: 1/8 inch rubber capsule w/ Levonorgestrel (synthetic progestin) can last up to 5 years Depo-Prevara Massive dose of progestin injecterd every 3 months (popular among teenage girls in U.S. ‘cause no pills to remember to take) Emergency Contraceptive Pills (ECP) post-coital within 72 hours (not RU- 486)
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Female Natural Methods Breast Feeding as long as you can –The “Bellagio Consensus” –While it has long been known that breastfeeding can delay the return of fertility, until recently the conditions under which women could reliably take advantage of this phenomenon were not clear. In 1988, scientists meeting in Bellagio, Italy, proposed how postpartum women could use lactational amenorrhea as a family planning method. From research reviewed at that meeting, they concluded that women who are not using family planning, but who are fully or nearly fully breastfeeding and amenorrheic, are likely to experience a risk of pregnancy of less than 2 percent in the first six months after delivery. (Consensus Statement: Breastfeeding as a Family Planning Method, The Lancet, 19 November 1988). This conclusion came to be known as the "Bellagio Consensus." Vaginal douching –Don’t count on it –Sperm can go from vagina to cervical canal in 15 seconds –May increase risk of Pelvic Inflammatory Disease
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Male Methods Condoms: Very Effective if used correctly Condoms reduce the spread of AIDS Withdrawl: (‘coitus interuptus’) –Unsatisfying and Ineffective –Priesthood (?)
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Couple Methods The Rhythm Method (users are known as ‘Parents’ ) Rhythm not only natural family planning method Fertility Awareness Method (goes both ways) A) Ovulation method (change in mucous) B) Basal Body Temperature Method (change in temp) C) Combo – Sympto-Thermal Method
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Pre-Modern or “Traditional” Methods Abstinence Withdrawl Douch Ethnobotany –Mostly ineffective –Resulted in many infanticides, ugly abortions, and abandonments
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Table 5.3 Contraception use
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How effective are contraceptives? Theoretical Effectiveness –Tough to measure Use Effectiveness –Incorporates human foibles Note: If an average couple were to spend an ‘average’ year together relying on Nothing but chance to avoid pregnancy there is an 85% chance that they would get pregnant.
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Voluntary Infecundity Female –Tubal Ligation (getting your ‘tubes tied’) –Hysterectomy (removal of the uterus) Male –Vasectomy –Castration In 1982 surgical methods passed all others as most common in United States By 1995 2/3 of all women using contraception did it surgically
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Gestation Variables 1) Miscarriage 2) Abortion 3) RU-486 (day after pill)
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Abortion 1) Legal in Canada 1969 2) Legal in US in 1973 (Roe vs. Wade) 3) Legal in 3 most populous countries of the world (China, India, United States) 4) 1 in 4 pregnancies in the world today is aborted.
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Abortion Continued…. Single most often used form of birth control in the world today Abortion is a big reason why fertility is low in many parts of the world today including U.S., Canada, Europe, and China Abortion rate increased in U.S. from 1973-1990 but has dropped since Abortion rate in Mexico high (yet still illegal)
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Measuring Abortion Abortion Rate: # of Abortions / 1,000 women aged 15-44 Abortion Ratio: # of Abortions / 1,000 known pregnancies
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Abortion Rates And Abortion Ratios Around the world
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Abortion 1) Surgical 2) Medical (RU-486) 97% of abortions done in the 1 st trimester Americans are very Pro-Choice
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Fertility Control Summary
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Measuring Fertility Period vs. Cohort Data Period data refer to a particular calendar year and represent an annual cross-section of the population at one specific time. Cohort measures of fertility “ are designed to follow the fertility of groups of women as they proceed through the childbearing years of life. In other words, period rates focus on the experience of specific calendar years, but cohort rates focus on the experience of groups of women over a number of years.” The ‘Synthetic Cohort” – Don’t know reality of cohort data until it has occurred therefore not very useful for projections.
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Period measures of Fertility Crude Birth Rate (CBR) General Fertility Rate (GFR) Child-Woman Ratio (CWR) Age-Specific Fertility Rate (ASFR) Total Fertility Rate (TFR) Gross Reproduction Rate (GRR) Net Reproduction Rate (NRR)
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Crude Birth Rate (CBR) ‘Crude’ cause it does not account for age and sex structure of the population Used a lot cause it is easy to calculate U.S. (14) Canada (11) Mexico (23) High Niger (51) low Bulgaria (8)
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General Fertility Rate (GFR) GFR usually 4.5 times the CBR GFR in 1968 was 88 in 1935 was 78 despite that CBR was 19 in 1935 and 18 in 1968
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Child – Woman Ratio This measure relies solely on census data CWR in U.S. in 1980, 1990, & 2000 ~265 CWR in Mexico 1990 was 489 today 408
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Age Specific Fertility Rate (ASFR) Requires a lot of vital registration and census data ASFR (20-24) in 1998 was 111; in 1955 it was 242 ASFR (25-29) in 1998 was 116; in 1955 it was 191 This helps clarify period vs. cohort data problems
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Total Fertility Rate (TFR) The total fertility rate is an estimate of the average number of children born to each woman, assuming that current age specific birth rates remain constant. TFR in U.S. in 1998 was 2,058 / 1,000 or 2.058 children / woman
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Gross Reproduction Rate Looking at female births only (a value of 1.0 is replacement if all women live to reproduce) U.S. in 1998 was just about 1
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Net Reproduction Rate (NRR) NRR like the GRR but takes into account that fact that all women do not necessarily reach child-bearing age. In the Developed countries like the U.S. NRR very close but less than GRR. In countries with higher death rates (e.g. Ethiopia) NRR can be significantly less than GRR.
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Cohort Measure #1: Completed Fertility Completed Fertility: Ask women over 50 how many children they had in their live and average it. Like TFR but an actual cohort measure. Women in U.S. in 1933 had highest completed fertility since 1881 and have not been equaled since.
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Cohort Measure #2: Intended Fertility Survey women as to how many children they want to have. This measure is often wrong as to timing but often close as to completed fertility
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Loretta Lynn and the Sexual Revolution Check out this NPR ‘Fresh Air’ interview with Loretta Lynn http://www.npr.org/player/v2/mediaPlayer.html?action=1&t=1&islist=false &id=131097120&m=131197083http://www.npr.org/player/v2/mediaPlayer.html?action=1&t=1&islist=false &id=131097120&m=131197083 Loretta Lynn’s “The Pill” A controversial song at the time
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