Spontaneous Conception

Medically unassisted human conception includes the following steps:

1. Ovulation 

    

   Fourteen days prior to the beginning of a new menstrual cycle, an ovarian follicle releases a microscopic egg. Shortly after ovulation, the egg is captured by one of the Fallopian tubes and brought inside the tube.

    

   

    

2. Fertilization 

    

   Sperm, which can wait in the Fallopian tubes for several days, must fertilize the egg within 12 to 16 hours of ovulation.

    

   

    

3. Early embryonic development

    

   The fertilized egg (embryo) moves through the Fallopian tube and starts to divide the day after fertilization. In two days, it has 4 cells, in three days, 8 cells, and in six days it has over 100 cells.

    

   

    

4. Endometrial lining

    

   The female hormones estradiol (estrogen, E2) and progesterone, produced by the ovulating follicle, prepare the lining of the uterus for implantation.

    

5. Implantation

    

   Five to seven days after ovulation, the embryo hatches out of its egg shell, implants into the lining of the uterus and starts to produce the pregnancy hormone Human Chorionic Gonadotropin (HCG). HCG can be detected with a blood pregnancy test approximately 9 to 10 days after ovulation. A urine pregnancy test will typically need close to two weeks after ovulation to turn positive.

   

If you have any questions regarding the process of conception or to request an appointment, please contact us by phone at 650-322-0500, via email at care@BayIVF.com, or use the Contact Bay IVF Center form on this page.