1. ‘‘I want a Boy’: the preconceptionI want a Boy’: the preconception
folklorefolklore
By Langhit Kurar (March, 2011)

2. OUTLINEOUTLINE
Urban myths and preconceptions
Disadvantage and Diversity
- Religious and cultural implication
Shettles’ (theory?)
Evidence-based medicine
- ‘Your child is what you eat’
- ‘Be the boss’

3. Urban Myths and PreconceptionsUrban Myths and Preconceptions
E.T.C.
!
MYTH BOY GIRL
‘Your child is what
you eat’
- India
red meat, salty
food, soya
sweets, fish,
vegetables
‘Joy of sex’ sleep on LHS,
love standing up
missionary
position,
woman
orgasms first
‘Its all in the timing’
- China
woman's head
facing north,
quarter moon,
odd days
full moon,
even days
‘Keeping cool’
- India
high stress,
warmed testicles
relaxed,
cooled
testicles
‘Be the boss’
- Africa
male-dominated
relationship
female-
dominated
relationship
‘Hairstyle’ straight across duck-tailed

4. Religious and Cultural ImplicationReligious and Cultural Implication
Sex selection big business
 In India, abortion of girls on the rise.
 Common amongst wealthy-access to USS.
 10:3 (B:G) in some states (NBS).(1)
 Land inheritance, ‘dowry’ customs common themes.
 Illegal to disclose sex of unborn or abort based on
gender-practice on increase.
‘Pay Rs 5000 today
and save Rs 5 lakhs
tomorrow.’
-Advertisement

5. Religious and Cultural ImplicationReligious and Cultural Implication
Missing women of China
 One-child policy (1979) correlates with gender-based birth rate disparity.
 30 million more men than women (2020) predicted (NBS).
 Underreporting female live births, diseases affecting female mortality, illegal
sex-related abortion, infanticide and child abandonment.(2)

6. Shettles’ (Theory?)Shettles’ (Theory?)
 First reputed child conception idea to determine baby’s
sex.
 ‘How to Choose the Sex of Your Baby’- publ.1970, claims
>75% effectiveness (3)
.
Basic Concept (timing of intercourse)
» X-bearing Sperm
- Slower and larger than their Y-
bearing counterparts.
- More resilient, longer-lived.
» Y-bearing Sperm
- Faster and smaller than their X-
bearing counterparts.
- More fragile, short-lived.

7. ‘‘Your child is what you eat’Your child is what you eat’
 244 female mice fed high
saturated fat content
produced 60% male offspring
vs. 274 controls producing
48% male offspring (P<0.0001).
(5)+(6)
Trivers-Willard hypothesis (1973) (4)
» Trivers’ trivial assumptions
1)Parental condition associated with offspring condition.
2)Differences in offspring condition will persist into adulthood.
3)Being in condition affects mating success of one sex more than the other.
‘Good condition’ hypothesis or ‘Adaptive’ theory

8. ‘‘Be the boss’Be the boss’
Maternal dominance hypothesis (1996) (7)
Maternal dominance:
serum testosterone
chance of male fetus

9. ‘‘Be the boss’Be the boss’
 Faecal testosterone is elevated in
high-ranking female ibexes (<0.05)
and associated with more male
offspring vs. subordinate females (8M
vs. 5M).(8)
 Ova development in follicular fluid
high in testosterone is more likely to
be fertilised by Y-chromosome-
bearing spermatozoa.(9)
 Recent trial (2010) reported median testosterone levels higher in follicles that
resulted in male embryos (32.12 ng/ml) than female embryos (23.98 ng/ml).(10)
Study N (embryos) Follicular
testosterone:
min–max (nM)
Median follicular
testosterone
of subsequent embryos (nM)
Significance (P)
Male Female
(9) 171 11-977 122.60 90.75 0.032
(10) 140 13–893 111.36 83.13 0.06

10. (11)

11. ConclusionConclusion
 Controversial Debate
 Social implications
 Little scientific evidence
 Shettles Theory, Maternal Condition and Dominance

12. REFERENCESREFERENCES
1) "Current status of abortion in India". Consortium on National Consensus for Medical Abortion in India.
http://www.aiims.ac.in/aiims/events/Gynaewebsite/ma_finalsite/report/1_1_1.htm. Retrieved 2011.17.03.
2) Johansson, S; Nygren, O (1991). "The missing girls of China: a new demographic account". Population and Development Review
(Population Council) 17 (1): 35–51.
3) “The Shettles Method of Sex Selection”. Robin Elise Weiss, LCCE,About.com Guide.
http://pregnancy.about.com/od/genderselection/a/shettlesmethod.htm. Retrieved 2011.17.03.
4) Trivers RL;Willard D (1973).“Natural selection of parental ability to vary the sex ratio of offspring.” Science 179: 90–92.
5) Alexenko AP,:Mao J; Ellersieck MR;Davis AM;Whyte JJ (2007) “The contrasting effects of ad libitum and restricted feeding of a diet
very high in saturated fats on sex ratio and metabolic hormones in mice.” Biology of Reproduction 77:599–604.
6) Cameron EZ;Lemons PR;Bateman PW;Bennett NC (2008) “Experimental alteration of litter sex ratios in a mammal.” Proc Royal Soc
of London. Series B 275 323–327.
7) GrantVJ;Irwin RJ (2005) “Follicular fluid steroid levels and subsequent sex of bovine embryos.” Journ of Experimental Zoology
303A1120–1125.
8) Shargal D;Shore L;Roteri N;Terkel A;ZorovskyY;Shemesh M;SteinbergerY (2008) “Fecal testosterone is elevated in high ranking
female ibexes (Capra nubiana) and associated with increased aggression and a preponderance of male offspring.” Theriogenology 69
673–680.
9) GrantVJ;Irwin RJ;Standley NT;Shelling AN;Chamley LW (2008) “Sex of bovine embryos may be related to mothers’ preovulatory
follicular testosterone.” Biol of Reproduction 78 812–815.
10) Garcia-Herreros M;Bermejo-Alvarez P;Rizos D;Gutierrez-Adan A;Fahey AG;Lonergan P (2010) “Intrafollicular testosterone
concentration and sex ratio in individually cultured bovine embryos.” Reproduction, Fertility, and Development 22 533–538.
11) Dama MS; Singh NM; Rajender S (2011) “High Fat Diet Prevents Over-Crowding Induced Decrease of Sex Ratio in Mice.” PLoS ONE
6(1): e16296.

13. ANY QUESTIONS?ANY QUESTIONS?