Twin's births can occur in about 2% of the pregnancies. The occurrence of twins could be due to:

*	A random throw of the nature’s dice which may result in a conception with more  than one pregnancy.
*	Multiple pregnancy may be due to hereditary factors.
*	Greater usage of fertility drugs in infertile women or elderly women, where   ovulation tends to be erratic.
*	The use of in-vitro fertilization (IVF), a procedure wherein eggs fertilized in   a test-tube are implanted in the uterus and as several ova are involved, there   is increased risk of multiple births.

More than 90% of twin pregnancies, have a happy ending with the mother carrying the babies to term in a healthy condition. This has been mostly due to the advancement and usage of the ultrasound examination, so that there are few complications during pregnancy and delivery. However, there are certain precautions in order to achieve this:

 
Extra medical care: Expert medical monitoring with a possibility of frequent appointments with the doctor, in case of any signs of complications. There is an increased incidence of the discomforts of pregnancy namely morning sickness, indigestion, backache, constipation, haemorrhoids, oedema, varicose veins, shortness of breath, for which you will need to consult the doctor more frequently and seek medical advice.

  

Extra nutrition: Most problems of multiple pregnancy can be solved by excellent nutrition, the importance of which cannot be stressed. A superior diet programmed with an additional protein and whole grain serving, supplemented with additional calcium serving and a good adequate supply of other nutrients such as iron, folic acid, zinc, copper, Vitamin B, Vitamin C and Vitamin D would go a long way in achieving a baby’s weight of 6 lbs (instead of 4-5 lbs) and a healthy mother, strong enough to look after her babies.

  

Extra rest:  As there are two babies you will need that much extra rest, for its efforts needed for baby building. Spend fewer hours at work and stop work when you fatigue out easily. As there is extra weight gain in multiple pregnancy, your obstretician will monitor the weight very intently. This could be anywhere between 30-35 lbs above your prepregnancy weight. This weight gain can further add to your discomforts. As there is an increased incidence of early labour, you need to keep even pre-requisite ready earlier and be prepared to deliver before your due date.