Pregnancy Updates for Muggles (fetal development, Harry Potter edition)

It’s Harry Potter’s birthday today (July 31)! And in honor of this occasion, I’m thrilled to welcome to the blog today Emily Martin – a PhD candidate in English at Oxford University, my very dear friend, and a dedicated Harry Potter fan.

Emily created this amazing first post in a new series I will be running on fetal development, helping us conceptualize the size and incredible growth of a baby at different points in pregnancy. While these comparisons may not be exactly reflective of any one particular baby, they give us a sense of the incredible growth that humans experience during the first nine months of their development.

With that, and a lot of gratitude for bringing the magic to this new series, I’ll turn it over to Emily.

Dear Fellow Potter Fans,

Image courtesy of Emily

I first read the Harry Potter series when I was 16, after completing my freshman year of high school. At school, I was one of the only students who hadn’t ever read the series, and I felt out of the loop in my friend group as the only one who didn’t understand all the cool Harry Potter references and jokes. I watched the first movie with a friend that summer, but still wasn’t totally on board. I knew I had to read all of the books before I could make up my mind. So I bought the complete Harry Potter paperback box set, knowing that if I only bought one book at a time, I might bow out and not finish the whole series. From the first chapter of Harry Potter and the Sorcerer’s Stone, I was hooked. I was enthralled with the magic, the social commentary, and especially the humor! 

If you’re a fellow Potter fan and want to follow along with your or a friend’s pregnancy, here’s a handy guide to fetal development for Muggles!

Fetal Development: Harry Potter edition

Up through week 9: Baby is growing to the size of a Bertie Bot’s Every Flavor Bean.

Week 10: Baby is almost as long as Hermione’s Time Turner (1.4 inches in diameter)

Week 11: Baby weighs as much as a Felix felicis vial, full of the potion (1.5 ounces)

Week 12: Baby grows as long as a Golden Snitch (1.9 x 1.84 x 1.4 inches)

Week 13: Baby grows to be the size of a wizard chess piece (2-4 inches tall)

Week 14: Baby becomes as long as the Sorcerer’s Stone (15cm)

Week 15: Baby’s now the length of Mad Eye Moody’s hip flask (17cm)

Week 16: Baby weighs as much as a Chocolate Frog (5.3 ounces)

Week 17: Baby gets as big as Hermione’s purse (20cm deep)

Week 18: Baby grows from the size of a Quaffle (8.5 inches in diameter) to the size of the Golden Egg Harry has to steal in the Triwizard Tournament (about 9 inches)

Week 19: Baby is as long as Fleur Delacour’s wand and Minerva McGonagall’s wand (each about 9 ½ inches) 

Week 20: Baby is almost as long as Remus Lupin’s wand (at 10 ¼ inches), as tall as the Triwizard Cup (25.5cm), or as tall as Slughorn’s hourglass (10 inches)

Week 21: Baby grows to be almost as long as Hermione Granger’s wand (10 ¾ inches long) 

Week 22: Baby is just longer than Harry Potter’s wand (11 inches long)

Week 23: Baby is as long as Cedric Diggory’s wand or the Monster Book of Monsters textbook (just over 12 inches)

Week 24: Baby is as long as Bellatrix Lestrange’s wand, which Hermione used for a time (12 ¾ inches) 

Week 25: Baby weighs as much as an Invisibility Cloak (about 898 grams) 

Week 26: Baby gets as tall as a folded up Daily Prophet newspaper (almost 14 inches)

Week 27: Baby is as long as Ron Weasley’s second wand (the one he got just before his third year at Hogwarts, just over 14 inches long) 

Week 28: Baby is the length of the Elder Wand (15 inches long) 

Week 29: Baby is now as long as the Marauder’s Map is tall (15.5 inches)

Week 30: Baby grows as long as Hagrid’s wand or as long as the largest dragon egg (about 16 inches long)

Week 31: Baby weighs as much as a full wizard chess set (3.75 pounds) or a small cauldron (almost 4 lbs)

Week 32: Baby weighs about as much as Hedwig (between 4 and 5 lbs) 

Week 33: Baby weighs the same as a small tent, such as the one the Weasley’s took to the Quidditch World Cup or Harry, Ron, and Hermione used to camp out in the Deathly Hallows (4 pounds, 13 ounces)

Week 34: Baby is as long as a Hogwarts trunk is deep (about 17 inches)

Week 35: Baby weighs as much as the Order of the Phoenix Illustrated Edition, the longest book in the Harry Potter series (5.6 pounds)

Week 36: Baby grows as long as Dolores Umbridge’s wand (8 inches) AND Draco Malfoy’s Wand (10 inches) lined up next to each other (18 inches) 

Week 37: Baby weighs the same as the complete Harry Potter paperback box set (6.6 pounds)

Week 38: Baby is about as long as a Hogwarts house tie hanging down a person’s chest (tied around a collar; about 19-20 inches) 

Week 39: Baby is the heavy as a replica of the Gryffindor Sword (3,500 grams)

Week 40: Baby gets as long as the Sorting Hat is tall (23 inches)

Week 41: Baby is the same weight as a full grown female cat, like Hermione’s cat Crookshanks or Professor McGonagall in her cat form (8 pounds)

Image courtesy of Emily

Want a handy printout version of this post to put up on your fridge? Download it below!

Emily Martin is a doctorate student at Oxford studying English. Her research interests include theology and culture, religious aesthetics, feminism, and Renaissance literature. Her doctorate focuses on Edmund Spenser’s poetry and how it responds to reformed debates over the role of religious images in worship. She is a FemCatholic contributor and has written about secular prolife organizations, pastoral care for post-abortive women, and maternity leave. She grew up in Southern California, where she learned to love going to the beach and eating Mexican food. 

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