Diaphragm are dome-shaped rubber plastic covers that have to be fitted on the cervix in the female's vagina to check the entry of sperms into the uterus.
Oral pills are the hormonal tablets are taken orally. These pills contain a combination of synthetic hormones like progesterone and estrogen. These hormones inhibit ovulation and implantation by inhibiting the secretion of FSH and LH from the pituitary gland.
IUDs (Intrauterine Devices) are made of plastic, metal, or a combination of the two and are inserted into the uterus to prevent conception.
IUDs increase phagocytosis of sperms within the uterus and the hormone releasing IUDs make the uterus unsuitable for implantation and the cervix hostile to the sperms.
Lactational amenorrhea is also a natural method of birth control where there is no menstrual cycle and therefore ovulation does not occur during intense lactation following parturition.