Mum who lost her baby to whooping cough reveals how difficult it was to have her third baby.

It’s an unimaginable anguish. The happiness and joy at a pregnancy, but the despair that it comes when it’s after the loss of another baby.

That’s exactly what Catherine Hughes – the Perth mother who lost her baby son Riley to whooping cough – has revealed.

In an emotional post, Mrs Hughes, who recently gave birth to Lucy in August, expressed the torment and delight, the happiness and grief she went through in giving birth to her “rainbow baby”.

In March 2015, Catherine and Greg Hughes’ world changed when they lost their four-week-old baby boy Riley to whooping cough.

Just days after he started coughing, Riley died, devastating the small family and waking many Australians up to the importance of getting a whooping cough vaccine during pregnancy.

In August, they announced the birth of baby Lucy writing: “We are delighted to announce the safe arrival of Riley’s sister - our precious rainbow baby. Both mum and bub are doing very well considering the emotional challenges faced after the loss of our brave boy.”

Now Catherine Hughes has shared a little of just what those challenges were, in a post that will speak to thousands of other families who’ve lost a baby.

“Today I thought I'd share my experience of what it has been like having a 'rainbow' baby (that is, a baby born after the loss of a child),” she said on her Facebook page, Light for Riley.

“The day we found out Lucy was a girl, I was hit with a huge wave of different feelings,”

“More grief, knowing that I will probably never have a son again. Relief, thinking it would be easier for me to hold a baby girl after the loss of a boy. Excitement, thinking of our beautiful daughter Olivia being able to play with her baby sister. And lastly, I felt worried. Worried that I would lose her. Worried that something would be wrong with her. And to be frank, I was worried about how I would cope having a newborn again. Would I be a wreck?”

She says the pregnancy was busy and she was exhausted.

“I couldn't wait to give birth, put my feet up and enjoy some quiet time with our new baby!”

Mrs Hughes and her husband Greg agreed to allowed cameras from Channel Seven to be a part of her birth in order to promote her drive to boost vaccination rates in Australia.

She says having the cameras there was strange but that she did it for Riley.

“I find myself agreeing to all sorts of weird things that I am not particularly comfortable with, feeling I owe it to Riley. I think deep down I feel so guilty that he died and hopeful that if I work my butt off, trying to prevent this from happening to others, that maybe one day I will feel less guilt.”

She says that the first few weeks were hard.

“I remember feeling that everyone expected me to be happy now, that I had Lucy and could move on with my life. I was happy in a way, but those first few weeks were HARD. I think I had over-romanticised what it was like to have a newborn baby, I thought it was going to be so easy, but it was difficult.

"I kept dressing her in pink and focused on the fact she was a girl, telling people 'she looks so different to Riley', trying to convince myself that looking at her didn't make me think about him. But it wasn't true really... she still had ten tiny fingers, ten tiny toes, soft skin and big blue eyes. She still made me think about him so much, especially in those quiet moments at 2am when it was just her, me and the darkness.”

She then explains how her most difficult time came when Lucy was 32 days old, the same age as Riley was when he died.

“When Lucy turned 32 days old, I was a bit of a mess. Riley was 32 days when he passed away and I kept thinking about the day he died. How he was so real one minute and gone the next. I don't think I put Lucy down that day.”

It’s still hard, she explains, but the parenting side is getting easier.

“Lucy is 3 months old tomorrow and I think I've started to get the hang of her! She is starting to chill out a bit more and has become a great sleeper at night time - what more could I ask for!”

“Her big blue eyes still remind me of her brother but she really is developing her own little personality. One day I will have to explain to her all about her 'big little' brother Riley.”

“I know that her existence doesn't magically heal us from losing Riley, but she is a blessing. Her name means 'light' (a completely unintentional coincidence!) and she has certainly given us light in a time when things have been tough for our little family.”