Relvay makes a pregnancy pillow. We also tell you below when you should not buy one.
The short answer
Pick a U if you switch sides often and have the bed space. Pick a C if you mostly sleep on one side, want an open side, or share a smaller bed.
- U: support on both sides, but it takes about half a queen.
- C: smaller and open on one side, but turning means flipping it.
- Decider: how often you switch sides.
Why switching sides decides between a C and a U
A C pillow supports one side of you, so when you turn over, the support is in the wrong place. A U pillow has support on both sides, so you can turn inside it. Everything else follows from that.
2:05 a.m.
Andrea was 29 weeks with a C pillow she loved for the first hour. Then her left hip ached and she turned to the right. Now the curve of the C was behind her, her bump had nothing under it, and the knee part was out of reach. So she sat up in the dark, dragged the whole C over to the other side, and lay back down. Ben woke up both times she did it.
"U shape or C shape is best?"YouTube comment on a pregnancy pillow video
"I don't flip my C shape. I just switch sides."YouTube comment on a pregnancy pillow video
Some people never turn, and a C is perfect for them. Others turn all night, and a C turns every switch into a small project.
C-shaped vs. U-shaped pregnancy pillow at a glance
Here is what each shape does for your head, your bump, your back and your way out of bed, before and after you switch sides.
| C-shaped | U-shaped | |
|---|---|---|
| Head | Top curve can be your head pillow | Top curve under your head |
| Bump, first side | Supported by the long side | Supported by one arm |
| Back, first side | Open, nothing behind you | Supported by the other arm |
| After you switch sides | Curve ends up behind you; flip it or go without bump support | Arms swap roles, no moving |
| Open side for getting out | Yes, the open side | No, climb out the end or over an arm |
| Partner can lie close | On the open side | Hard, there is a pillow wall |
| Bed width | Less than a U | About 28 to 31 in, half a queen |
| Airflow | One side open | Surrounded |
A C pillow fits a body that stays on one side. A U pillow fits a body that keeps switching, if the bed can afford it.
What is good and bad about a C-shaped pregnancy pillow?
A C pillow gives you head, bump and knee support on one side in a smaller footprint than a U. The catch is everything behind you, and every switch of sides.
Good:
- Takes less of the bed than a U, which matters on a full or queen.
- One side stays open, so getting up and cuddling are easier.
- The top curve can double as your head pillow.
Harder:
- Switching sides means flipping it or giving up bump support.
- No support behind your back unless you add a pillow there.
- If you are petite or tall, the head and knee parts may land in the wrong places. Our size guide shows how to check.
What is good and bad about a U-shaped pregnancy pillow?
A U pillow surrounds you, so both sides are covered and you can turn without moving it. The catch is size and the feeling of being enclosed.
Good:
- Bump and back are supported on either side.
- Turning over needs no rearranging.
- Head, back, bump and knees in one piece.
Harder:
- A typical U is about 59 to 63 inches long and 28 to 31 inches wide, close to your whole half of a queen.
- Getting out to pee means climbing out of the end or over an arm.
- Some people feel boxed in, and a pillow on both sides holds more warmth.
"Get swallowed up in, hard a hard time turning."Amazon review of a pregnancy pillow
"My husband can still cuddle me while I'm using the pillows and that I don't feel trapped inside the pillows."Customer review of a compact pregnancy pillow
Which one fits the way you sleep?
Count how often you switch sides and how much bed you have. Those two answers usually decide it.
- I mostly stay on one side all night: C.
- I switch sides several times a night: U.
- I share a full or queen bed: C, or something smaller.
- I get up to pee more than twice: C, for the open side.
- I want my partner able to lie close: C, on the open side.
- I have a king bed to myself: U.
If you ticked U for turning but C for the bed and the bathroom trips, neither letter fits you well. That is where smaller setups come in. For bed width in detail, see pregnancy pillow for a small bed.
Pain that keeps you awake is worth raising with your midwife, OB-GYN or a pelvic health physical therapist. A pillow is a comfort aid, not a treatment.
What Andrea did when neither shape fit
She needed support on both sides, like a U, and an open side and room for Ben, like a C. So she stopped choosing between the letters.
Andrea kept the C on the couch for reading. In bed she moved to two small wedges joined by a strap, one under her bump and one behind her back, with her own head pillow and a regular pillow between her knees. When she switched sides at 2 a.m., she lifted her bump onto the other wedge instead of dragging a whole C across the bed. On Saturday morning Ben was still asleep beside her, close enough to steal half her blanket.
Frequently asked questions
Is a C-shaped or U-shaped pregnancy pillow better?
It depends on how often you switch sides. A U supports both sides so you can turn without moving it, but it is large. A C is smaller and leaves one side open, but you flip it when you turn.
Do you have to flip a C-shaped pregnancy pillow when you turn over?
To keep bump support, yes. If you turn without flipping it, the curve ends up behind your back and your bump has nothing under it. Some people accept that and just switch sides.
Is a U-shaped pregnancy pillow too big for a queen bed?
It takes about your whole half. A typical U is 28 to 31 inches wide and half a queen is 30 inches. Your partner keeps his side, but there is little room for both of you to lie close.
Which pregnancy pillow shape is easier to get out of bed with?
A C, because one side is open. With a U you climb out of the end or over an arm, which matters if you get up several times a night.
Is a C or U pillow cooler to sleep with?
A C leaves one side of your body open to the air, so many people find it less warm than a U that surrounds them. The cover fabric matters as much as the shape.
Where the Relvay 3-Piece pillow fits in
To be clear, Relvay does not make a C or a U pillow. If you have decided on one of those shapes, buy that shape. The Relvay 3-Piece is for people like Andrea who need support on both sides but also want an open side and room for a partner.
Two wedges for bump and back, joined by a flat strap, about as wide as your torso. Keep a regular pillow between your knees. $79.99, 90-day returns.
Probably not for you if
- You want a C or a U. This is neither.
- You want one pillow that also holds your head and knees.
- You sleep alone in a big bed and love being surrounded.
Made for you if
- You switch sides often but a U is too big for your bed.
- You like a C's open side but not flipping it.
- You are fine keeping your own head pillow and a pillow between your knees.
Andrea's story is a composite based on real reviews and public posts from pregnant side sleepers. Names and details are changed.
