contraception 1

The ideal form of contraception would be 100% effective, completely reversible, totally acceptable & absolutely free of side effects.
No such method exists.
Assessment of effectiveness by Pearl index: is the number of unwanted pregnancies which occur in 100 women using that method for a year.
1-Methods not requiring medical consultation:
A-Coitus interrupts:
Withdrawal of penis at the moment before ejaculation. It causes psychological symptoms in both couples. Failure rate is high, pearl index is 18. Failure occurs from delay in withdrawal or because the pre-ejaculatory fluid may contain some spermatozoa
B-Condom:
It has the advantages: that is readily available in most societies, does not need medical supervision & provides protection against sexually transmitted diseases. Pearl index is 5.Occasional failures occur because the sheath is defective, or because it is not worn in the earlier phases of coitus.Recently female condom is polyurethane sheath inside the vagina, protect against sexual transmitted disease.
C-Safe period (rhythm or calendar method):
The method is based on the assumption that the ovum is capable of being fertilized for only 24 hours after its release, & that the sperm can fertilize the ovum for only 72 hours after they are deposited in the vagina. If ovulation occurs between days 12-16 of a 28 day cycle; the fertile period during which coitus should be avoided between day 9= (12-3) & day 17= (16+1) of the cycle.
Calendar method; relies on an analysis of the women’s menstrual data over the preceding 12 months. So the range of the beginning & end of her fertile period is to deduce 18 days from the shortest cycle & 11 days from her longest cycle.
This method of contraception is not suitable for women with very irregular periods.
An attempt may be made to predict the time of ovulation by recording the basal body temperature first thing in the morning, coitus is avoided for 72 hours after the rise in temperature has occur.