Método Shettles
Dr. Landrum Shettles proposed that Y-sperm (male) are faster but shorter-lived, while X-sperm (female) are slower but more resilient.
- Menino: Perto da ovulação.
- Menina: Antes da ovulação.
Método Shettles.
Dr. Landrum Shettles proposed that Y-sperm (male) are faster but shorter-lived, while X-sperm (female) are slower but more resilient.