طريقة شيتلز
Dr. Landrum Shettles proposed that Y-sperm (male) are faster but shorter-lived, while X-sperm (female) are slower but more resilient.
- للولد: قريب من التبويض.
- للبنت: قبل 2-4 أيام.
طريقة شيتلز.
Dr. Landrum Shettles proposed that Y-sperm (male) are faster but shorter-lived, while X-sperm (female) are slower but more resilient.