Is it normal for a newborn to lose weight after birth?

Why does she weigh less than she did

We asked this properly — why does it happen, and how much is too much — because it's one of the first numbers you're handed and it goes in the wrong direction.

We asked this while Ari was in NICU, when every number felt enormous. Weight was the one number we felt we could follow.

Most of it is fluid

Babies are born with extra fluid on board and shed some of it in the first days. Milk supply is still arriving at the same time, so intake takes a few days to catch up.

Some early loss is expected. It isn't a failure of anything, and it isn't a verdict on how feeding is going. Knowing that doesn't make being handed a smaller number on day three feel any better — everything in you wants that line to go up — but it does stop you reading it as a result.

The shape matters more than the number

Loss over the first few days, a low point, then it turns around. Back to birth weight somewhere around two weeks. Then steady gain along her own line.

The turning point is the bit to watch. Any single weighing is noisy — different scales, different clothes, a full nappy weighs something. We were weighing her every second day and learning to ignore the wobbles between the trend.

We stopped using the internet's percentage

There's a specific figure quoted everywhere for how much loss is too much, and for us it was simply the wrong measure.

Ari was born at 33 weeks, weighing under 2 kg. Her doctor and nurses had their own chart and expectations, and a general number written for full-term babies did not describe her. We spent a while trying to place her on growth lines we did not have before we finally asked the people who did.

If your baby is under specialist care, ask your baby’s doctor or nurse what they expect and what would worry them. Then you know what you are watching for instead of comparing your baby with a stranger’s baby.