John Legend and Chrissy Teigen
John Legend and Chrissy Teigen struggled to have a baby for years Mike Windle/Getty Images for A E Network

Sports Illustrated model Chrissy Teigen and wife of singer John Legend has found herself defending her admission that she was able to choose the sex of her unborn child while undergoing IVF treatment after facing fierce scrutiny from fans.

After some followers claim that the move was selfish, she hit back at the criticism, saying her critics were "reaching for outrage" and that there were more important things that warranted the indignation.

In a string of messages, she told her 1.3m Twitter followers that she refused to feel bad about her decision to have a daughter.

"What year is this!? And for the record, I am always happy and open to speak on infertility. The more casual, the better! I don't mind.

"I also picked the embryo with a taste for bacon, a knack for magic and size 7 feet so she can always find shoes.

"What is that difference though? I've already created embryos with a doctor. Only after must it be random?"

When a follower claimed that she should have considered adoption as infertility meant she was not supposed to have children, she fired back that whether her child was natural or the result of IVF "my daughter will never speak to another human like this, @baby_c_69".

In October 2015, the Teigen used Instagram to reveal that the happy couple were expecting their first child, writing: "John and I are so happy to announce that we are pregnant :)" she captioned the image on Instagram. "As many of you know, we've been trying to have a baby for a while now.

The baby news come weeks after she opened up about their fertility struggles during an episode of her new show, FABLife. "I will say honestly John and I were having trouble. We would have had kids five, six years ago if it happened. But my gosh it's been a process," Teigen said at the time. "We've seen fertility doctors and once you open up about those things to other people you learn that a lot of other people in your life are seeing these people and they have this shame about it."

The social media-savvy beauty tied the knot with Grammy Award-winning musician on Lake Como, Italy after four years of dating.