The Myth: In India it is believed that during an eclipse one must not wander out, since it is believed that the Sun is swallowed up by the demon. Pregnant women, specifically, must stay indoors in order to ensure that their babies are not born with any deformities. In fact, pregnant women are often stopped from sewing or cutting vegetables during an eclipse. Some families avoid cooking and eating altogether during an eclipse.
Traditional reason: This ancient myth has been traced back to the Aztecs. They believed that an eclipse was a bite on the face of the moon. If a mother watched it, the same thing would happen to her baby.
Mythological Reason: Going by ancient astrological beliefs, Rahu and Ketu are malefic planets. Legend has it that once there was a strife between Rahu and the Devtas (Gods ) both wanting to claim nectar for immortality. When Vishnu dressed as Mohini seduced Rahu by the charm and stole the nectar from him, Rahu decided to trick the Devtas and get it back. So, he disguised himself as a Devta and waited for his turn to get a drop of ‘Amrit’ .He managed to get some into his body,but to his disappointment Surya and Chandra recognized him. Vishnu chopped Rahu’s head but he survived that and his body got split into two parts. However to take a revenge against Surya and Chandra , Rahu decided to cast a shadow on both , which is what we know as Surya and Chandra Grahan (Solar and Lunar Eclipse respectively). It is this legend that gives rise to the traditional belief that ‘Grahan Kaal’ is an inauspicious period during which evil forces are active , especially harmful for pregnant woman .
Scientific reason: However, the reason behind some of these superstitions can be scientific.
For example, one should actually avoid going out during an eclipse in order to keep away from the harmful UV rays. So basically this holds true not only for pregnant women but also any other person.
There is a belief that vegetables shouldn’t be cut during an eclipse, because the sun’s rays are blocked due to which the presence of microbes and germs in the atmosphere increases due to a cooler temperature.
So this is the history on the superstitions about eclipses.