There is no magic number

We spent real effort trying to pin down when the forty days started — from her birthday, or from her due date, since she arrived early. We did the arithmetic several times.

The forty days is custom rather than medicine. It's a reasonable instinct dressed up as a deadline, and the arithmetic doesn't produce an answer because there wasn't one to find. What it points at is true — a newborn's immune system is still developing, and a baby born early is more vulnerable for longer. Plus once her 40 days were up we entered flu season which again messed up our calculations.

How we said it

A flight is not the same as a walk outside. Hundreds of people, shared air for hours, and every surface touched by everyone.

Most respiratory infections declare themselves within a few days of being caught, which is why a few days of distance between a flight and a newborn is the common-sense version of the advice. The honest position is that this is reasonable rather than precisely calibrated — nobody is going to hand you the correct number.

This was the hard part. Telling someone who has flown to meet your baby to wait a few days is a difficult message, and the way we found to do it was to give a date rather than a rule. Papa had to fly for work and come back, and whilst the help was really needed, he wore a mask, and for the first two days didn’t get close to little Ari.

"Let's not do it now — come over on Thursday and stay a while" works. "We're not having visitors until forty days after her due date" invites a negotiation about the number. A date is warm and specific.

What mattered in the house

Once someone is in the house, the mechanics are more important than the waiting period.

Hands washed with soap and water before picking her up — every time, not once on arrival. We had an argument about sanitiser versus washing at one point, and the honest answer is that washing properly is better and that doing either reliably beats doing the better one occasionally. Nobody unwell holds her, and "just a cold" is not a small thing for a newborn.

Call your doctor immediately if

Blue or grey, a pause or struggle to breathe, or a floppy baby you cannot wake — call your local emergency number now.

  • She's under three months with a temperature of 38°C or above
  • Laboured breathing — ribs pulling in, nostrils flaring, grunting
  • Pauses in her breathing, or she goes pale, grey or blue
  • She's floppy, very hard to wake, or her cry has changed