Whether by choice or by accident, having kids close in age can be a blessing or a major headache.
What is life like with two under two, three under three and four under four?
We asked three mums with multiple little ones for an inside peek at their lives.
Two under two: 'I haven't had more than three hours sleep in a row for two years'
Shelley Walsh, 42, Sydney
Every time I went to the doctor as a single woman in my thirties, I'd be told I should consider freezing my eggs if I wanted to have children. It gave me the perception that it would be difficult to conceive at my age.
I met my husband when I was 37 and I was lucky that I conceived easily a month after I got married. I was 40. My husband and I wanted a second child, and I assumed it would take about 12 months for me to conceive. But I fell pregnant when our son Tom was only five-months-old.
I was breastfeeding him regularly, so getting pregnant came as a real shock. I felt sorry for Tom, because I felt I hadn't given him all the one-on-one time he needed. I weaned him two weeks before I gave birth to Ava because I didn't want to go cold turkey on him while I was in hospital. He wasn't yet walking and I just felt really guilty.
In the beginning, I felt overwhelmed. I wondered how I would ever leave the house.
I started off doing walks around the block, or I'd load up the car and go for a short trip. I didn't tackle shopping for a long time. When I did go out, I'd get comments like, "You must be busy" or "How do you cope?"
Tom was so young when Ava arrived that he just accepted her – there was no jealousy. My husband and I were still in the nappy phase, so there was no mental adjustment there. I've had friends who struggled with a bigger age gap because they felt like they'd forgotten everything.
Ava is now 10-months-old and Tom is two, and I can already see that they're going to be really close. Tom is protective of her and Ava gets so excited when she sees her brother after he's had a sleep. I'm happy that things happened this way. I think there's a lot to be said for getting the baby stuff out of the way.
Sleep has been a disaster though. Ava had reflux and Tom was already a terrible sleeper, but when you've got two under two, they are both going through lots of developmental stuff, and the sleep regressions can hit hard.
I haven't had more than three hours sleep in a row for two years. When they sleep at the same time during the day it's a miracle – and my first priority is a shower or a nap.
Three under three: "I became less stressed as I had more kids"
Natalie Stuart, 35, Melbourne
I was an only child and I always wanted a big family, but it wasn't a conscious decision to have our kids close in age. When my youngest child was born, I had three under three plus a six-year-old. My youngest is now 10-months-old.
When my eldest daughter was little, I was always worrying how I was doing as a parent. Was I was reading enough books to her? Taking her to enough play groups? Should she be transitioning from this to that? How many words should she be saying?
But as I had more kids, I was like, 'Who seriously has time to worry about those things? Just get on with it.' I don't have time to over-think stuff. I actually became less stressed as I had more kids.
I don't entertain my kids very often and I don't have that expectation of myself, as many other parents do. Some mums say to me, 'I can't get anything done because so-and-so wants me to play with them all the time.' That's not my job. I mean, I will sit down and play with them – just yesterday we made a big Lego house. But they don't ask me to play with them often because they entertain each other!
The only way I manage everything is because my husband and I work for ourselves and it's a complete 50:50 split. Our whole family wakes up together and my husband and I come home together at 4.30pm.
People say rude things to me about having lots of little ones. One guy said, "Why the f-- would you have four?" And one of my friend's husbands likes to make the same joke over and over: "Should I be congratulating you? Are you pregnant again?"
Sometimes people think they are being funny but they're not. Anyway, I don't care. We are really happy and my children bring me so much joy.
Four under four: "Harder than being in a war zone"
Tamara Sloper-Harding, 41, Sydney
I was 33 when I had my first child, and we knew we wanted four children. I also had this idea – which was stupid in hindsight – that if I had all my babies close together I could get back to work quicker.
My husband was in the defence force so he was away all the time. I had no idea that it would be harder than being in a war zone.
There are decisions you make because you have four kids that other people can't understand. I couldn't take them to the park or the beach on my own because I couldn't watch them all. I couldn't really go out because of all the different naptimes.
In a way, I would have preferred twins because the sleep times would have been the same. Instead, we did lots of painting and crafts at home, though it was always such a mess at the end of the day. I also hosted craft nights at my house. That really saved my sanity as I got to talk to other mums.
When my husband was around, he would sit with the kids in the food court while I had the treat of grocery shopping on my own. That was the only alone time I ever had.
I had a triple pram with the skateboard attachment on the back. I had a strap on my four-year-old's wrist and people in the street would tell me off, saying a strap was old-fashioned. But if he ran off, I couldn't leave three babies sitting there while I chased him.
Sometimes it was draining. I'd often fall asleep while reading my kids a story at night. I also did some naughty things. Sometimes I'd turn the clock forward and tell them it was bedtime. But when my oldest was four he could read the other clocks in the house so it stopped working.
Bath time was hard. I lived in a three-storey house and I could never carry them all at once. I'd have to leave one in a playpen and one in a high chair, screaming, while I carried the other two up the stairs. I put a baby seat on the floor in the bathroom while I tried to bath the two toddlers. Sometimes I'd be crying.
The blessing was when we decided to move to Sydney from Brisbane, because my parents lived around the corner. My dad would come around at 6am so that I could have a shower.
When I was pregnant with my youngest, I had to carry an ice-cream container at the bottom of the pram and I'd stop stop and vomit every now and again. My oldest would hold my hair back when I threw up. Once, when we were in the supermarket, I had to say, 'Oh no, that's not ice-cream in there...'
There are so many good aspects to having had my kids close together. They all liked the same stuff and now they're teenagers and really close. Nowadays, having the emotional capacity to make sure I've checked in with everyone is hard.
Knowing the ins and outs of the friendship groups is actually more exhausting. I think the best time was when they were in primary school and still went to bed early.