f. Diaphragm. This method involves the use of a mechanical block in
conjunction with spermicide. Specifically, a mechanical device is inserted in the vagina.
A spermicidal product is applied around the diaphragm. Theoretically, this
mechanical/chemical block should prevent pregnancy. Actually, approximately five of
100 couples who use this method find the female pregnant. The advantage of this
method is that no hormone is used. The disadvantages of this method are that the
diaphragm must be fitted (requires a prescription) and there is some difficulty in
inserting the diaphragm.
g. Intrauterine Device (IUD). This method involves the use of a mechanical
device (like a coil or loop) placed within the uterus. The IUD is believed to prevent the
implantation of the fertilized ovum. There are various types of these intrauterine
devices available. Some intrauterine devices contain chemicals (like copper or
progesterone). Approximately five of 100 couples who use this method find the female
becomes pregnant. The advantage of this method is that no chemicals are used
(except in the two types that contain chemicals). Disadvantages associated with
intrauterine devices are that they are not always inserted properly by the females and
they can move and irritate tissue. Further, the intrauterine device can present problems
to the female and fetus if the female becomes pregnant while the IUD is in place, if the
IUD is removed there is a high likelihood of a miscarriage.
h. Surgical Techniques. A vasectomy is a surgical procedure that blocks the
flow of sperm from the epididymis. This procedure is very effective. A tubal ligation is a
surgical procedure that blocks the movement of ovum in the female. Both methods are
extremely effective in making the individual sterile. The advantage of these surgical
methods is that they are both effective and permanent. A disadvantage is that they are
permanent, although some success has been achieved in surgically reversing the
i. Oral Contraceptives.
Mechanism of action. Oral contraceptives act by three methods:
(a) Increase an estrogen level that inhibits ovulation by feedback action
on the hypothalamus and subsequent suppression of the follicle-stimulating hormone
(FSH) and lutinizing hormone (LH).
(b) Increases progesterone levels prior to ovulation, which inhibit the
implantation of the ovum within the uterus.
(c) Affect the quality of the mucous in the vagina (the mucous
becomes thick, scanty, and cellular) in order to hamper the movement of sperm.