Anne Lynch reflects on the ups and downs of adding a third child to her family.

"Congratulations. Um, er, I think. I mean, it wasn't an accident was it?" Not unless you consider grabbing your husband's hand, running down the passage to the main bedroom giggling like teenagers, flopping down on the bed and staring up into his eyes, before nodding that yes, a third child would be a brilliant idea, to be accidental.

My optimism was soon shattered by everyone's reaction. I thought they would be thrilled but instead, we received a lukewarm response. I realised then that people had no idea how to react to the news. Most of them were like stunned mullets, offering up platitudes like great... super... fantastic, just to fill the void. I could tell that people were questioning why I would consider having a third. I had a boy and a girl already. What was the point?  Nobody had a third anymore.

A third is different from a first or a second. Everyone considers a first baby to be the most precious of all. And no sooner has the excitement about the first settled than people begin to question when you are going to have a second. You can't possibly just consider having one.

During your second pregnancy, concerns abound as to how you will cope with two. Everyone seems less tolerant of your second pregnancy, as you have been there before. The most popular comment is, "You are going to have your hands full". Then you produce a girl, so you have a pigeon pair and there's no reason to continue on to number three. Or so it seems. A friend who has two boys has been subjected to constant questioning about when she was going to try to have a girl. Apparently she is not meant to be happy with her 'lot' in life.

Society is obsessed with twos. It makes perfect sense. The number two has a certain resonance. Two is the first prime number and the only even one. There are the famous pairings: Holmes and Watson, David and Goliath, Hansel and Gretel, Romulus and Remus; food pairs: bacon and eggs, salt and pepper, bangers and mash; pairs in philosophy: nature versus nurture, good and evil, yin and yang. And let's not forget that two was the designated number of each animal taken on board the ark.

Three, however, has been overlooked. It too is a prime number - the first odd prime number and the only triangular prime number. There are three stars in Orion's belt and Earth is the third planet in the Solar System. There are three types of volcano, three basic rock formations, three primary colours, and three is approximately the value of pi. Plato split the soul into three parts. Three is a hat-trick. Three strikes and you're out.

There is nothing spontaneous about a third. Everything is planned - it has to be. Your schedule dictates your obstetric appointments. Your ultrasounds are not meant to be exciting. Even when you get that happy surge lying on the radiographer's bed, seeing the little life growing, you are not meant to be overwhelmed. How could you be? You've done this twice before.

Another thing that pegs you as 'odd' is that you don't want to know the sex. You want it to be a surprise. You don't particularly care if the nursery is blue or pink. What matters is that you have a healthy bundle. A little surprise. But you forget, you are no longer entitled to be excited. This is, after all, your third.

It is then that you start questioning your motives. Was it a mistake? Did we really think it through?  Is this really what we want? The unrelenting commentary does not cease for one instant. You are constantly told that you are either "carrying very small" or you are "all baby". Gloom sets in. Your optimism is slowly being eroded by the overwhelming negativity surrounding you. Then one day when you are at your lowest, your son says, "Do you need a rub on your back, Mummy? Is the baby making it sore?" And suddenly you realise that you have been under everyone else's influence for too long. You have allowed the negativity to creep into your pregnancy like an uninvited guest.

A surge of optimism returns. You begin to realise that these people will not be at your disposal when you need them in the early hours of the morning. It is your little family that will rally around you, making you endless cups of tea, feeding you biscuits and marvelling at the little life that you have created. Their excitement is tangible, and remarkably, once again, so is yours.