Serena Williams was ''dying inside'' the day she found out she was pregnant.

The 36-year-old sporting icon discovered she was expecting her first child last year at the Australian Open in Melbourne and although Serena wanted to immediately tell everyone her fantastic news, she had to keep it quiet.

Serena and Internet entrepreneur Alexis Ohanian welcomed their daughter Alexis Olympia Ohanian on September 1 and the pair tied the knot in November.

In addition to a year of personal highs, Serena also had an exciting professional year too as she won the Australian Open when she was nine weeks pregnant.

She shared a number of pictures from 2017 on Instagram and included a message about her highlights.

She wrote: ''This year has been amazing for me. As it comes to its end I want to share 10 personal moments. 1. The day I found out I was pregnant. I had to pretend I everything was normal but I was dying inside. After all I had a grand slam to play. 2. Melbourne 7 weeks pregnant 3. Wow I won the Australian Open. I was 9 weeks by than. No one knew outside of venus and my fiancé Alexis 4. Everyone got me stuffed animals for my bridal shower. 5. 24 weeks. 6. bridal shower by @thevlvgroup 7. still hitting at 7.5 weeks 8. @vanityfair cover of the year for me 9. Just about ready to pop 10. The day before I checked into hospital to have my amazing baby (sic).''

Meanwhile, Serena recently shared her hopes and wishes for her little girl in an open letter to her mother Oracene as she thanked the 65-year-old tennis coach for always being there.

She wrote: ''Dear Mom, You are one of the strongest women I know. I was looking at my daughter (OMG, yes, I have a daughter) and she has my arms and legs! My exact same strong, muscular, powerful, sensational arms and body. I don't know how I would react if she has to go through what I've gone through since I was a 15 year old and even to this day ...

''I've been called man because I appeared outwardly strong. It has been said that that I use drugs (No, I have always had far too much integrity to behave dishonestly in order to gain an advantage). It has been said I don't belong in Women's sports - that I belong in Men's - because I look stronger than many other women do. (No, I just work hard and I was born with this badass body and proud of it) ...

''I am proud we were able to show them what some women look like. We don't all look the same. We are curvy, strong, muscular, tall, small, just to name a few, and all the same: we are women and proud! (sic)''