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How to Adjust Your Mattress Firmness During Pregnancy

By Soft n Comfort Editorial Team Updated April 20, 2026 11 min read

TL;DR

Medium-firm is the ideal mattress firmness for most pregnant women — soft enough to relieve hip and shoulder pressure during side sleeping, firm enough to keep the spine in neutral alignment. If your current mattress is too firm, a 2 to 3-inch gel memory foam or latex topper is the fastest and most affordable fix. If it is too soft, a dense latex topper or plywood board under the mattress adds firmness. Choose toppers with CertiPUR-US or OEKO-TEX certification to minimize off-gassing. Many mattress brands offer 100-night trials, making a full mattress replacement feasible during pregnancy without financial risk.

Key takeaways

Medium-firm (5 to 7 on a 10-point scale) is the target firmness for side-sleeping pregnant women.
A 2 to 3-inch gel memory foam or latex topper fixes a too-firm mattress for $45 to $200, significantly cheaper than a new mattress.
Always air out new foam toppers or mattresses for 48 to 72 hours before sleeping on them during pregnancy.
Add a waterproof mattress protector over the topper to protect both from pregnancy-related fluid exposure.
Many mattress companies now offer 100-night trials — make this work for you if you are considering a full replacement.

At 26 weeks pregnant, you already knew the mattress was getting worse. But at 32 weeks, waking up with a hip that feels like it is on fire, it becomes undeniable: the firm mattress that was fine before pregnancy is now a sleep quality problem. Or the opposite — you are sinking into your pillow-top so deeply that your back hurts by morning and your belly feels like it is pulling toward the mattress. Mattress firmness issues during pregnancy are real and fixable. Most of the time you do not need to buy a new mattress — a properly chosen topper resolves the problem at a fraction of the cost and effort. This guide explains how to diagnose your mattress issue, choose the right topper, use it safely during pregnancy, and know when a topper is not enough. Pair it with our mattress firmness matcher tool for a personalized recommendation, and see our best mattresses for pregnancy guide for a full mattress replacement if that becomes necessary.

Why Mattress Firmness Matters More During Pregnancy

Pre-pregnancy, most people can tolerate a range of mattress firmnesses because they sleep in multiple positions — back, side, stomach — and the body weight is distributed differently. During pregnancy, particularly from the second trimester onward, you are almost exclusively a side sleeper. Side sleeping concentrates body weight at the hip and shoulder — the two bony landmarks with the least natural padding. On a too-firm mattress, these points create pressure against an unyielding surface. On a too-soft mattress, they sink unevenly, pulling the spine out of the neutral alignment that protects the lumbar vertebrae and hip joints through eight hours of sleep.

The situation is further complicated by the belly: in the second and third trimesters, the belly hangs toward the mattress when you lie on your side. This creates a rotational pull on the pelvis and lower back. A properly firm mattress combined with a pregnancy pillow under the belly counters this rotation by providing a stable, supportive surface that the pillow can work against effectively.

How to Diagnose Your Current Mattress

Too Firm

Signs: hip pain and shoulder pain that worsen through the night and peak in the morning; you can feel distinct pressure points at your hip and shoulder when lying on your side; there is a visible gap between your waist and the mattress surface when lying on your side (the mattress is not conforming to your body curve).

Too Soft

Signs: lower back pain that worsens through the night; you feel like you are "in" the mattress rather than "on" it; the mattress has visible permanent indentations in your usual sleeping spot; your hips sink significantly lower than your torso when lying on your side, creating a visible spinal curve.

Appropriate Firmness

Your hip and shoulder sink slightly into the surface (enough to relieve pressure), but your spine remains in a roughly straight line when viewed from behind while lying on your side. No significant gap at the waist. No feeling of sinking uncontrollably. You wake up without localized pain that improves when you get up and move.

Find your ideal mattress firmness

Answer 4 quick questions to see which firmness range and mattress type fits your body and sleep style during pregnancy.

Open the tool →

Adding a Topper to a Too-Firm Mattress

A mattress topper is placed on top of your existing mattress and changes the feel of the sleeping surface without replacing the underlying structure. For a too-firm mattress, you need softening and pressure relief:

Gel Memory Foam Toppers

The most popular option. Gel infusion reduces heat retention compared to traditional memory foam — important during pregnancy. A 2-inch topper adds meaningful softening; a 3-inch topper is more significant. The Lucid 3-Inch Gel Memory Foam Topper ($89–$199) is one of the most-reviewed options and offers CertiPUR-US certification. The LinenSpa 2-Inch Gel Topper ($45–$99) is a budget-friendly entry point.

Best Budget-Friendly Topper

Lucid

Lucid 3-Inch Gel Memory Foam Mattress Topper

★★★★★ 4.5 · 75000+ reviews

Ventilated gel memory foam for airflow
3-inch thickness adds plush cushioning
CertiPUR-US certified foam

$89-$199 Check Price on Amazon →

Latex Toppers

Natural latex offers pressure relief similar to memory foam but with more responsiveness — it bounces back quickly when you move rather than slowly recovering. It also off-gasses less than synthetic foam, which is relevant during pregnancy. OEKO-TEX or GOLS-certified latex toppers are the cleanest chemical option. The Pure Green 100% Natural Latex Topper ($199–$349) is a popular choice for pregnant women sensitive to chemical smells.

Pillow-Top Toppers

Down-alternative or fiber-fill pillow-top toppers add plushness and cushioning but provide less targeted pressure relief than foam or latex. Good for a moderately firm mattress that needs softening but not significant pressure point relief. The ViscoSoft 4-Inch Pillow Top Topper ($199–$329) combines a foam base with a fiber top for both support and plushness.

Dual-Layer Support

ViscoSoft

ViscoSoft 4-Inch Pillow Top Memory Foam Topper

★★★★☆ 4.4 · 18000+ reviews

2-inch gel memory foam + 2-inch fiber pillow top
Removable cover with corner straps
CertiPUR-US certified

$199-$329 Check Price on Amazon →

Adding Firmness to a Too-Soft Mattress

Fewer options exist for firming up a soft mattress. High-density foam or natural latex toppers rated at medium-firm or firm can add some resistance to a moderately soft surface. A plywood board (3/4 inch thick, cut to the mattress size) placed between the mattress and box spring or platform is a low-cost way to add firmness to a too-soft mattress. It is temporary and somewhat inelegant, but it works. If the mattress is severely soft with permanent body impressions deeper than 1 to 1.5 inches, a topper will not provide sufficient structural correction — replacement is the better path.

Safe Topper Selection During Pregnancy: Certifications

New foam products release VOCs initially. During pregnancy, chemical sensitivity is often elevated and you are spending 7 to 9 hours in close contact with the material. Look for:

CertiPUR-US: US standard limiting specific VOC emissions and excluding certain toxic substances from polyurethane foam.
OEKO-TEX Standard 100: Broader textile certification limiting a wider range of harmful substances.
GOLS (Global Organic Latex Standard): For latex toppers made from certified organic rubber.
GREENGUARD Gold: Stricter VOC limit certification appropriate for products used by chemically sensitive individuals and children.

Regardless of certification, unbox and air out any new topper in a well-ventilated space for 48 to 72 hours before sleeping on it. See our common pregnancy pillow mistakes article for more context on off-gassing during pregnancy.

When to Replace the Mattress Entirely

A topper cannot fix a structurally compromised mattress — one with coils that have lost tension, foam that has permanently collapsed, or permanent body impressions deeper than 1 to 1.5 inches. If you have tried a quality topper and still wake with pain that resolves when you get off the mattress, the mattress needs replacing. Many mattress companies now offer 100-night trials. Starting a trial at 20 to 24 weeks gives you time to evaluate the mattress during the most demanding period of pregnancy. If you replace the mattress, see our best mattresses for pregnant women guide for options that have performed well for side-sleeping pregnant women across different price points.

Using a Protector with Your Topper

Add a waterproof mattress protector over the topper and under your sheets. Pregnancy increases the risk of fluid-related mattress or topper staining — from sweat, amniotic fluid leaks in late pregnancy, or postpartum fluid. The SafeRest Premium Mattress Protector ($35–$65) has a breathable cotton terry surface that avoids the uncomfortable crinkle of cheaper plastic-backed protectors, and it is OEKO-TEX certified. The Utopia Bedding Waterproof Protector ($20–$40) is a budget option with similar functional properties.

Not medical advice. Always consult your OB-GYN about pregnancy-related health decisions, including back and hip pain management.

Frequently Asked Questions

What mattress firmness is best during pregnancy?

Medium-firm is the most commonly recommended firmness for pregnant women — typically a 5 to 7 on a 1 to 10 firmness scale. This level provides enough give to cradle the hip and shoulder (critical for side sleepers, which most pregnant women become) while maintaining enough support to keep the spine in neutral alignment. Very soft mattresses allow too much hip sinkage, which bends the lumbar spine. Very firm mattresses create pressure points at the hip and shoulder, causing pain and frequent repositioning. Your current weight and build also affect how a given firmness feels.

Can a mattress topper help with pregnancy back pain?

Yes, if the source of back pain is mattress firmness. If your mattress is too firm, a 2 to 3-inch gel memory foam or latex topper can relieve the hip and shoulder pressure that indirectly pulls the lumbar spine out of alignment when side sleeping. If your mattress is already appropriate in firmness and your back pain persists, the issue may be pillow support (use a full-body pregnancy pillow), pregnancy weight distribution, or a musculoskeletal condition that would benefit from physical therapy. Consult your OB-GYN or a prenatal physical therapist if back pain is significant.

Is memory foam safe during pregnancy?

Memory foam made with CertiPUR-US certified foam meets standards that limit VOC emissions (volatile organic compounds) to levels considered acceptable for indoor use. New memory foam does off-gas initially — most of the odor dissipates within 24 to 72 hours of unpacking in a well-ventilated room. During pregnancy, when smell sensitivity is heightened, it is worth unboxing a new memory foam topper or mattress and airing it out for 48 to 72 hours in a separate room before sleeping on it. Certified organic latex toppers (GOLS certified) off-gas less than memory foam and are another option for chemically sensitive pregnant women.

When during pregnancy should I adjust my mattress?

Most women notice their mattress becoming problematic between 20 and 28 weeks, when the belly is large enough that side sleeping creates significant hip pressure on a too-firm surface. If you are planning to buy a topper, do it by week 20 so you have it in place before discomfort peaks at 30 to 36 weeks. If you are considering a new mattress, many brands offer 100-night trials — starting the trial at 20 to 24 weeks gives you time to assess whether it works before committing, and allows you to keep it for the postpartum period when sleep quality also matters enormously.

How thick should a mattress topper be for pregnancy?

2 to 3 inches is the sweet spot for most pregnant women adding a topper to a too-firm mattress. A 2-inch topper adds meaningful softening for side sleepers without creating excessive sinkage. A 3-inch topper is appropriate if the underlying mattress is very firm (8 or above on a 10-point scale) or if you are carrying twins and need more pressure relief at the hip. Toppers thicker than 3 inches (4 inch and above) can create too much sinkage for back alignment unless the underlying mattress is medium-firm to firm as a structural base.

Is it safe to sleep on a new mattress or topper during pregnancy?

Yes, with a short off-gassing precaution. New foam products release VOCs most heavily in the first 24 to 72 hours. During pregnancy, when smell sensitivity is high and you are spending many hours in close contact with the sleeping surface, it is worth unpacking the product in a well-ventilated room or outside, letting it air out for 48 to 72 hours, and ensuring good bedroom ventilation for the first week of use. CertiPUR-US and GREENGUARD Gold certified products have lower VOC emission profiles than uncertified products. Certified organic latex is the lowest-emission option.

Can a too-soft mattress cause problems during pregnancy?

Yes. A mattress that is too soft allows the heavier parts of the body — hips and torso during pregnancy — to sink further than the lighter parts, creating a banana-like curve in the spine rather than a neutral line. This misalignment causes lower back pain that worsens through the night and is noticeable in the morning. The fix for a too-soft mattress is more limited than a too-firm one: a dense latex or high-density foam topper can add firmness, or a plywood board under the mattress can increase base firmness. Both are temporary measures; a structurally compromised soft mattress often needs replacement rather than modification.

Does the mattress matter as much as the pregnancy pillow for sleep comfort?

Both matter, but they work at different scales. The mattress determines the foundational support and pressure distribution for your entire body. The pregnancy pillow fine-tunes alignment — belly lift, back support, knee separation — within the environment the mattress creates. A great pillow on a terrible mattress will not fully compensate for the mattress; an appropriate mattress firmness with a good pillow is the optimal combination. If budget is limited, prioritize the pregnancy pillow first (lower cost, higher immediate impact), then address the mattress if discomfort persists.