Getting pregnant naturally is a complicated process that involves multiple steps starting with the proper balance between reproductive hormones and production of egg in women and sperms in males. This can be studied under the following headings:

STRUCTURE:

Female reproductive system consists of vagina, cervix, uterus, 2 fallopian tubes and 2 ovaries on either side. Lowest part of the uterus is called as cervix opens into vagina where intercourse occurs. The upper part of uterus on either side opens a narrow tube-like structure called fallopian tube. Distal end of the fallopian tube has finger like projections called fimbriae which catches the egg/ ova released by the ovary and transports it to the uterus. Ovum/ egg is produced in the follicles in the ovaries and every month one follicle will mature to release the egg.

The male reproductive system has two testes stored in scrotal sacs and ducts which open into penis along with the urethra.

FUNCTION:

In men, every 72 days fresh sperms are produced from the age of puberty and this process continues throughout their life. So, at any point, the sperms are not more than 72 days old. However, in women it is different. Every woman is born with a fixed number of eggs after which there is no fresh production of eggs. So, a girl is born with millions of eggs but will have only a few lakhs of eggs at puberty and will have only a few thousands after 35 years. Her age is equal to the age of her eggs and the best eggs are recruited in the early part of reproductive life. So, the remaining eggs will be inferior in quality.

OVULATION:

Every month out of 5 – 6 ovarian follicles, only 1 follicle which is most sensitive to the hormones will grow. This is called as ‘dominant follicle’. Follicles are shell/ outer covering that contains the egg. Once it reaches 20mm, it ruptures to release the egg which is picked up by the fallopian tube. Egg remains viable/alive in the fallopian tube for 24 – 48 hours before which the sperm has to unite with it to form an embryo for pregnancy to occur. Otherwise, it degenerates and is released in the menstrual blood as periods.

During natural intercourse, sperms enter into the uterus through the vagina. The ones with the good motility can pass the cervix and reach the uterus and into the fallopian tube. Only if the sperm is healthy and fast enough, it will be able to fertilise the egg and an embryo is formed. After 3 days, this embryo is taken to the uterus by the pushing movement of cilia and after 5^th or 6^th day of embryo formation, it gets absorbed into the inner lining of the uterus(implantation).

When the embryo is implanting, beta HCG hormone level also increases and when levels are above 1000, a gestational sac can be seen in the uterus through transvaginal ultrasound.

Hope this helps in understanding how natural conception occurs. For further doubts or assistance, contact Fertility Foundation/SISU Hospital at +9194433 00000