In women, the risk of developing enlarged veins during pregnancy is high because as the uterus grows, there is additional pressure on their major veins. In turn, this causes additional pressure within the leg veins.
Additionally, the increased progesterone levels in pregnant women, coupled with the increased amount of blood in their body, adds even more strain on their leg veins.
During pregnancy, it is common for women to develop large bulging veins. Within one year after child birth their veins usually return to their normal size.
Women have a higher chance of developing permanent veins if they have gone through more than one pregnancy.