Baby's First Christmas: Matching Pajamas and Keepsake Ideas for New Parents

The short answer

For a first Christmas, buy baby christmas pajamas in the size your baby will be on December 25, not the size they wear today, and pick the print from a family listing so you and your partner can wear the same one. Check the 0-3M size first if your baby is very new or not yet born, because only a handful of PatPat's Christmas prints offer it. Then let safe sleep decide what the baby actually sleeps in on Christmas Eve: back to sleep, a bare crib or bassinet, and no hood. PatPat sells these pajamas, and the sizes and details below were read from our own listings in November 2026.

Your situation	What to do
Baby due in late November or December	Look for 0-3M on the print first; few prints have it, so choose the print around that size
Baby born this fall	Measure now and compare with the chart, then buy the size for late December
Baby 6 months or older	Most family prints cover 6-9M, 9-12M and 12-18M, so choose by print and family sizes
You want a keepsake	Buy the baby's piece and one parent's piece from the same listing, and plan to keep one

What Size Baby Christmas Pajamas to Buy for a December Baby

Buy for the baby you will have on Christmas morning. Today is November 8, so there are about seven weeks to go, and in the first months that is long enough to move a size. A baby who fits 0-3M now may fit 3-6M by Christmas.

PatPat's Christmas family listings sell baby pieces in month ranges. On the listings we read for this guide, almost every print offered 3-6M, 6-9M, 9-12M and 12-18M. The smallest size, 0-3M, was the exception: only a handful of prints carried it, among them the red Fair Isle, the khaki gingerbread, the green Christmas tree and snow globe, the dinosaur onesie and four licensed sets. No listing we read offered a newborn size. One licensed Frosty the Snowman set went up to 18-24M.

Baby's age on December 25	Size to check first	Watch out for
Not yet born, or under 1 month	0-3M	Few prints; a newborn may swim in it for the first weeks, so roll the cuffs for photos
1 to 3 months	0-3M or 3-6M	Measure length; a long baby may already need 3-6M
3 to 6 months	3-6M	Go up if your baby is at the top of the chart now
6 to 9 months	6-9M	The infant garment exception ends at nine months (see below)
9 to 12 months	9-12M	A crawler needs room at the knees
12 months and older	12-18M	Some prints stop here; one licensed print goes to 18-24M

The month label is a starting point. Babies vary, so compare your baby's length and weight with the PatPat size chart, and if you are between sizes on a one-piece, length usually decides. Our guide to newborn vs. 0-3 months sizing covers the first weeks in detail.

If the baby has not arrived yet, two practical points. First, a December due date means you will be ordering for a baby you have not measured, so choose a print that offers both 0-3M and 3-6M; then you can order the second size if the first is wrong. Second, keep the tags on until the baby has tried the piece on. PatPat's refund policy asks for items unworn, with tags, in the original packaging, and an exchange works as a return followed by a new order, so a size you need may sell out in between.

Infant Christmas Pajamas and the US Sleepwear Rules

The rules for infant christmas pajamas change at nine months, and it helps to know where your baby falls before you read a label.

US children's sleepwear has to pass a flammability test, with exceptions for garments made to fit tightly and for qualifying infant garments. The CPSC's page on infant and tight-fitting garments sets out the infant exception. To qualify, a garment must:

• be sized nine months or smaller;
• if one-piece, not exceed 64.8 centimeters (25.75 inches) in length;
• if two-piece, have no piece longer than 40 centimeters (15.75 inches);
• carry a label showing the size in months.

So a 0-3M, 3-6M or 6-9M baby piece may fall under the infant exception, while 9-12M and 12-18M pieces are covered by the full children's sleepwear rules, which allow a flame-resistant route or a snug-fitting route. We do not rank either as safer; they are two ways of meeting the same rule.

For the family listings in this guide, the question mostly answers itself. Most of their descriptions state that the kids' and babies' pieces are flame-resistant, made with a flame-resistant fiber blend. Keep to the care label, which is meant to protect that flame resistance, and read the label inside the baby piece when it arrives. If a listing you are considering does not state either route for the baby piece, ask PatPat before ordering. Our guide to baby pajama fabrics for sensitive skin covers fiber and labels in more depth.

These rules apply to children's sleepwear only. Your own pajamas, and the dog's bandana, are not covered by them.

Safe Sleep on Christmas Eve: What the AAP Recommends

A first Christmas usually means visitors, late nights, a different house and a baby who falls asleep in someone's arms. None of that changes the safe sleep rules. From the AAP's parent's guide to safe sleep:

• Place your baby on their back for all naps and at night.
• Use a firm, flat sleep surface.
• Keep soft objects and loose bedding out of the sleep area, including pillows and blankets.
• Share a room, not a bed, for at least the first six months.
• Dress the baby in only one layer more than you are wearing in the same environment.
• Don't put a hat on your baby indoors.

Here is how that applies to Christmas pajamas specifically:

Hoods come off for sleep. Some family onesies have hoods. Since the AAP advises no hats indoors, we would treat a hood the same way: fine for an awake photo, not for sleep. For a sleeping baby we would choose a hoodless romper.

The romper is the layer, not an extra one. If the room is warm and the adults are in one layer, the baby in a long-sleeve romper plus a diaper is likely enough. Feel the back of the neck: sweaty means too warm. If you use a wearable blanket, count it as a layer.

The sofa is the riskiest place in the house. The AAP says the risk of sleep-related infant death is up to 67 times higher when infants sleep with someone on a couch, soft armchair or cushion. On a long Christmas Eve, decide in advance who moves the baby to the crib or bassinet the moment they fall asleep, and do it even if it wakes them.

Visiting relatives? Bring or borrow a safe sleep space, such as a portable crib with a firm, flat mattress and nothing else in it. A guest bed with pillows is not a safe substitute. Our holiday travel packing list covers what to bring for a baby.

Socks and props. Many family sets come with a pair of buffalo plaid socks. Keep any extras out of the crib or bassinet, along with gift tags, ribbon and bows; the sleep space should hold the baby and nothing else.

Christmas Onesie Pajamas, Rompers and Two-Pieces: What the Baby Piece Is

On most PatPat family listings, the baby version is a one-piece romper, even when the adults' version is a two-piece top and pants. The descriptions say this directly: each size comes with one set of pajamas, or one romper, or one pet bandana. So "matching" means the same print and colors in a shape that works for a baby, not a shrunk-down adult set.

The christmas onesie pajamas work the other way round: the adults and kids wear one-piece hooded onesies too, and the whole family is in one-pieces. The dinosaur print set is one of these, with baby sizes from 0-3M. Its listing describes a front zipper and a hood with a 3D detail. It does not spell out how the baby version closes, so look at the baby photos on the listing before ordering if closures matter to you. Take the hood down when the baby sleeps.

Closures are where listings say the least. Of the listings we read for this guide, only the Christmas tree and car print mentions "shoulder and bottom snaps." Others describe the baby piece simply as a romper. If you have a strong preference, our guide to zippers vs. snaps on baby rompers explains the trade-offs for night changes, and it is worth checking the listing photos for the closure before you buy.

For a first Christmas specifically, three practical points:

• Diaper changes on the day. You will change the baby several times between the morning photos and dinner. A romper that opens at the legs makes that quicker than one you have to take off over the head.
• Dress after the last feed, before the photo. Spit-up on a light print is hard to hide. Put the romper on last, and keep a bib handy for the photo session.
• Buy two if it is the only outfit for the day. A second romper in the same print, or the same romper one size up, covers a blowout and gives you a backup if the first size runs short.

Matching Pajamas with Mom and Dad: Why the Same Print Matters in Year One

A baby will not remember their first Christmas. The photos are for the rest of the family, and a shared print is what makes a baby in a parent's arms read as part of the picture, not a separate subject. That is the case for buying the baby's piece and the parents' pieces from one listing. Each member's size is added to the cart separately, but it is the same print, the same colors and the same trim.

Two things are particular to the first year:

Babies are held in most photos. Your torso is the background behind your baby's face. A print that is busy on both of you can blur together, so a print with clear spacing or a two-tone design, such as the gingerbread and milk print on ice blue or the red Fair Isle, tends to read better than an all-over pattern at close range. That is our photo judgment, not a rule.

The size range has to cover everyone in the family photo. If grandparents, older cousins or a parent who needs a larger size will be in the picture, check those sizes on the same listing before you commit. The blue mug and gingerbread listing ran from baby 3-6M to adult 4XL when we read it, which is rare; on most prints the adult range stops at 2XL or 3XL. Our guide to National Family PJ Day has a plan for getting the photo done early.

If the family photo is the priority, browse cute christmas pjs by print first, then filter out anything that lacks your baby's size. The pet piece on these listings is a bandana, not a full set of pajamas, so the dog can be in the photo too.

Licensed character sets are another option for families who already have a favorite. PatPat's Frosty the Snowman and Harry Potter family sets offered baby sizes from 0-3M when we read them; their listings describe them as officially licensed Warner Brothers merchandise. The Frosty fleece set in light blue is one of the few listings that went up to 18-24M.

Baby's First Christmas Keepsake Ideas That Use the Pajamas You Already Bought

The best keepsakes from a first Christmas are the ones you can repeat. None of the ideas below needs anything extra from a store; they work with the pajamas, a phone and a notebook.

1. Same spot, every year. Choose one place that will still be there next year: the bottom stair, the front door, a particular armchair. Take the baby's photo there in their Christmas pajamas this year and every December after. Mark the spot with a small piece of tape on the floor under a rug so the angle stays the same.
2. The parent's sleeve shot. Lay the baby's hand on your forearm, both in the same print, and photograph just the hand and the two sleeves. It shows scale better than any measurement and repeats well each year.
3. Keep the first romper. Wash it once after Christmas, let it dry fully, and store it in a breathable cotton bag or acid-free tissue in a box, not a sealed plastic bag. Pin a note to it with the date, the size, and what the baby weighed.
4. Keep one parent piece too. If you plan to buy new pajamas next year, set aside one adult top with the baby's romper. Years later, the two side by side tell the story better than either alone.
5. Photograph the size label. A close-up of the "0-3M" or "3-6M" label next to the adult "L" is a small, funny record of how far the family has to grow.
6. A letter on Christmas Eve. Write one page to your baby about the day: who held them, what they wore, what woke them up. Fold it into the box with the romper.
7. The growth line. Lay the baby on their back on a plain blanket beside a tape measure in their Christmas pajamas, and photograph from directly above. Next year, do the same with the next size.
8. Everyone's hands. In the family photo, ask everyone to put one hand on the baby's romper. Matching sleeves from shoulder to wrist make an easy, close-cropped picture.

A note on photo sessions: keep them short, take them when the baby is fed and awake, and never prop a baby on a high surface. If the baby falls asleep during the session, stop and move them to their crib on their back.

Shop the look

For a keepsake family photo with a baby in arms, the whole family wears the gingerbread and milk print on ice blue, or the blue mug and gingerbread print if someone needs a size up to 4XL: one listing, choose each member and size.

Want to compare fabric weights before you choose? Our guide to Christmas pajama fabrics by climate compares fleece, cotton, bamboo viscose and satin.

A First-Christmas Pajama Timeline for New Parents

New parents are short on time, so here is the whole job laid out from today, November 8, to Christmas morning. Thanksgiving falls on November 26 this year and Christmas Day is a Friday.

When	Job	Why then
This week	Measure the baby's length and weight; pick a print that has the baby's size and every adult's size	0-3M and the largest adult sizes are the first gaps you will hit
Before Thanksgiving week	Order the baby's piece and the parents' pieces from the same listing, each size added separately	The shipping policy estimates 1–3 days of processing plus 2–5 business days in the contiguous US, and peak season can be slower
The day it arrives	Try the romper on with the tags still attached; read the label inside the baby piece	Returns need tags on, and a replacement means a new order
First week of December	Wash, then take the family photo while the size still fits	Babies grow fast, and an early photo leaves time for cards
December 23	Set up the sleep space at wherever you will spend Christmas Eve	A portable crib is easier to set up in daylight than at midnight
Christmas Eve	Romper on after the last feed, hood down, baby on their back in a bare crib	Safe sleep rules apply to festive nights too
December 26	Do the keepsake photo, then wash and store the romper with a dated note	The romper may not fit by New Year's

If the baby arrives early or late and the size is wrong, do not force it. A romper that pulls at the shoulders or bunches at the feet will not look right in photos either. Use the second size you planned for, or roll the cuffs on a slightly large one for the photo and keep it for January.

Frequently asked questions

What size Christmas pajamas should I buy for a newborn? Look for 0-3M, which only a few PatPat Christmas prints offer, and compare your baby's length with the size chart. No listing we read offered a separate newborn size.

Do baby Christmas pajamas need to be flame-resistant? In the US, garments sized nine months or smaller may qualify for an infant garment exception; larger sizes must be flame-resistant or snug-fitting. Most of the family listings here state that their baby pieces are flame-resistant.

Can my baby sleep in a hooded Christmas onesie? We would take the hood down or choose a hoodless romper for sleep, since the AAP advises against hats on babies indoors.

Is the baby piece the same as the adults' set? Usually it is a one-piece romper in the same print and colors, while adults wear a two-piece set.

Should I size up baby Christmas pajamas? Buy for your baby's size on December 25, which may already be one size up from today. If you are between sizes on a one-piece, length usually decides.

Can a baby sleep in Christmas pajamas on Christmas Eve? Yes, on their back, on a firm flat surface with no blankets, dressed in only one layer more than you are wearing.

How do I keep my baby's first Christmas pajamas? Wash once, dry fully, and store the romper in a breathable bag or acid-free tissue with a dated note.

Baby sizes go first: each size on a print sells out on its own, and 0-3M is offered on only a few prints, so check your baby's size before choosing the print for everyone else.

About this article

Written and fact-checked by the PatPat Editorial Team. How we research, source and review what we publish is set out on our editorial standards page.

Method. Baby sizes, baby piece types, closures and flame-resistance statements were read from PatPat product pages in November 2026. PatPat is the seller of these pajamas, and we did not wear-test any of them. The size-by-age table, the photo advice and the keepsake ideas are editorial suggestions. Safe sleep and regulatory points come from the AAP and CPSC pages listed below; this article is not medical advice.

Sources. Infant garment exception: CPSC, Infant and Tight-Fitting Garments. Children's sleepwear: CPSC, Children's Sleepwear. Safe sleep: AAP, A Parent's Guide to Safe Sleep.

Last updated 8 November 2026 · Next review November 2027