Ramanodge Unmathallegadoo, 51, burst into the home of eight months pregnant Sana Muhammad and fired an arrow into her stomach as she fled upstairs.
Mrs Muhammad, 35, formerly known as Devi Unmathallegadoo, suffered catastrophic internal injuries and died at her home in Ilford, East London.
Her unborn son - her sixth child - was delivered by Caesarean section and miraculously survived.
A jury rejected the defendant's claim it was an accident and found him guilty of murder after four hours of deliberations last week.
On Friday, Judge Mark Lucraft QC sentenced him to life with a minimum term of 33 years.
He described the killing of Mrs Muhammad as a "brutal and evil attack", saying if it was not for the presence of her children he would have shot her new husband Imtiaz too.
He told the defendant: "You have carefully planned this attack. You had two loaded crossbows and I'm entirely satisfied you intended an attack on Sana and then on Imtiaz.
"One can only assume that you were jealous of their life together and the fact that they had formed a loving bond between themselves and with your children. The judge said the crossbows and bolts the defendant acquired do not require a licence and can be bought online."
He said: "As is shown by events that followed, they can be used to devastating effect to kill.
"Many I am sure will find the ease with which some items are available deeply concerning - it is for others to consider whether these items should be controlled and require a license for ownership."
The court heard how the victim was just 16 when she entered into an arranged marriage with the defendant, then aged 30, in Mauritius.