New Project: How big is the baby?

New Project: How big is the baby?

We are expecting our first baby soon and like most first-time parents, we signed up for a bunch of pregnancy tracking apps that tell you how big your baby is each week. You know like, "this week your baby is as big as an eggplant".

As informational as they were, I didn't like a few things about them.

  1. I wanted to get daily updates, instead of just weekly updates.
  2. I wanted the updates to be a bit more fun and lively than the boring fruit and vegetable comparisons most apps provide.
  3. Most importantly, I wanted to receive them as SMS text message instead of another app notification.

If only there was a service I could use to sign up for these text updates for me, and my wife.

I couldn't find a service that would do these things. So, I built one for the both of us using Twilio and Airtable.

My wife and I have been using it last couple months, and we love it. It's cute and fun. It's become a part of our morning routine - waking up, and then one of us asking - how big is the baby today? We just glance at the message, and smile. It's a great way to start our day!

What's next?

Next, I plan to open this up to other soon-to-be parents, who would like to use it. I am keeping it invite only for now, while I work out the self-serve onboarding. In the mean time, I am looking for enthusiastic testers. So, if you would like to get early access, I have set up a waitlist on Please drop your deets here, and I will add you to the system.

Does it cost anything?

No. And I would like to keep it that way as long as I can sustain the monthly bill. It costs about 0.25c per user/per month to send the messages, plus $5/month for server cost. As long as I can keep this bill to under $20/month, I will keep the service free. Beyond that, I may have to add small one-time fee for new users.

Why SMS? Why not an app?

  • 👉🏽 Apps get lost in the noise: An average smartphone user has 41 apps installed. No one wants another app.
  • 👉🏽 SMS text messages cut through the noise. It's more intimate and personal. Most people (at least in North America) check their texts frequently.
  • 👉🏽 Easy sign up for partner/family members using their phone numbers. No need for them to download apps.

How did I collect the data?

I essentially scraped the internet for as much data I could find on this. I then searched for relevant pictures for each of them on Unsplash/Google Images. Given that most people keep the first three months pretty close to their chest, and may not be interested in receiving these updates, I collected the data starting the second trimester - that's week 13 to week 40.

How does it work

It's a pretty straightforward service that uses Airtable as the database, and Twilio to send the text messages. I have carefully collected the data for 190 days (week 13 - week 40) sitting in Airtable. A Python script picks up the daily update, and the relevant image URL from Airtable, and sends it as a multimedia message using Twilio.