Related Experiment Video
Updated: Feb 12, 2026

Population Replacement Strategies for Controlling Vector Populations and the Use of Wolbachia pipientis for Genetic Drive
Published on: July 4, 2007
Natural sex selection for safe motherhood and as a solution for population control
1Department of Obstetrics and Gynaecology, Batra Hospital and Medical Research Centre, 1 Tughlakabad Institutional Area Mehrauli-V Badarpur Road, New Delhi 110 062 India.
Abstract:
For Safe Motherhood wanted children should be of desired sex. As Y sperm have a shorter life span and migrate faster, if coitus occurs before ovulation, sperm must wait in the tube for the ovum to arrive. By the time the ovum arrives, Y sperm have died and X sperm fertilize the ovum, resulting in a baby girl. If coitus takes place after ovulation when the ovum is waiting in the tube, the faster migrating Y sperm fertilize the ovum resulting in a baby boy. Eighty women wishing to test this hypothesis by basal body temperature and ultrasound were recruited. Correct results have so far been obtained in 97%. This theory can be used for Safe Motherhood, for population control and to eliminate sex-linked genetic disorders. It can also prevent both female feticide and infanticide in some cultures.
Related Concept Videos
What is Natural Selection?
Natural Selection and Adaptation
Beyond physical adaptations,...
Limits to Natural Selection
Natural Selection and Mating Preferences
Females, due to their biological roles in conception, pregnancy, and nursing,...
Frequency-dependent Selection
Sex-linked Disorders

