Invisalign is generally considered safe during pregnancy. The aligners don’t involve medications, and the forces they place on teeth are mild. That said, pregnancy creates real changes in your mouth and body that can make treatment trickier, so there are practical things worth knowing before you start or continue wearing aligners.
What the Aligners Are Made Of
Invisalign’s SmartTrack material is a polyurethane-based plastic marketed as BPA-free. However, lab testing published in The Angle Orthodontist found that SmartTrack does release small amounts of both BPA and BPS, a related compound. Among several aligner brands tested, SmartTrack released the most of both chemicals.
Before that raises alarm bells: the amounts detected were far below the acceptable daily intake levels set by regulatory agencies. You’re exposed to more BPA from handling receipts or eating canned food than from wearing aligners. Still, if minimizing chemical exposure is a priority for you during pregnancy, it’s worth discussing with your orthodontist whether any adjustments make sense.
How Pregnancy Changes Your Mouth
Hormonal shifts during pregnancy increase blood flow to the gums and amplify your body’s inflammatory response to plaque. Up to 75% of pregnant people experience some degree of pregnancy gingivitis, with gums that are puffier, more tender, and more likely to bleed. Wearing aligners over inflamed gums can feel uncomfortable, and the snug fit of the trays makes thorough oral hygiene even more important than usual. Brushing before reinserting your aligners after every meal is essential to keeping bacteria from getting trapped against swollen tissue.
Your body also produces a hormone called relaxin during pregnancy, which loosens ligaments throughout your body. Rat studies have shown relaxin can temporarily increase tooth mobility by as much as 170%, though it doesn’t appear to speed up actual tooth movement. In practical terms, this means your teeth may feel slightly looser or more sensitive to pressure. Orthodontists sometimes adjust the pace of treatment to account for this.
Morning Sickness and Enamel
Frequent vomiting coats your teeth in stomach acid, which softens enamel over time. If you brush immediately after getting sick, you can actually scrub away that softened layer. The better approach is to rinse your mouth with water or a baking soda solution first, wait about 30 minutes, then brush. Remove your aligners before rinsing so you can clean both your teeth and the trays properly before putting them back in.
If morning sickness is severe, you may find yourself removing and reinserting aligners multiple times a day. This can make it harder to hit the recommended 20 to 22 hours of daily wear time. Some people find it easier to pause treatment temporarily during the worst weeks of nausea rather than fighting to keep aligners in.
The Snacking Challenge
Pregnancy often means eating smaller, more frequent meals to manage nausea, heartburn, or simple hunger. Every time you eat, you need to remove your aligners, eat, brush your teeth, and reinsert them. When you’re snacking six or seven times a day instead of three, that routine gets exhausting and cuts into your wear time significantly. Planning your eating into defined windows rather than grazing continuously can help, but be realistic about whether the aligner schedule fits your body’s needs right now.
X-Rays and Treatment Timing
Starting Invisalign typically requires dental X-rays for treatment planning. A standard dental X-ray delivers a radiation dose to the fetus of less than 0.01 milligray, which is thousands of times below the threshold where any effect on a pregnancy has ever been observed. The American Dental Association considers dental X-rays safe during pregnancy and no longer requires lead aprons or thyroid collars for them. That said, many orthodontists prefer to take any needed X-rays before pregnancy or postpone them until after delivery when the imaging isn’t urgent.
If you’re planning to start treatment, the second trimester (weeks 13 through 24) is the most comfortable window for elective dental work. Organ development is complete, nausea has typically eased, and you’re not yet at the stage where sitting still for long appointments becomes physically uncomfortable. The first trimester carries the highest rate of spontaneous miscarriage, so many providers prefer to avoid starting new elective procedures during those weeks. Routine dental care is generally avoided from the middle of the third trimester onward simply because of physical discomfort.
Managing Aligner Discomfort
New aligner trays often cause soreness for the first day or two. Outside of pregnancy, most people reach for ibuprofen. During pregnancy, pain relief decisions are more complicated. The FDA has stated that research on pain relievers during pregnancy is too limited to make firm recommendations, so any medication choice should involve your obstetrician. Non-drug options like cold compresses, dental wax over irritating edges, and switching to a new tray at bedtime (so you sleep through the worst pressure) are all reasonable first steps.
Already in Treatment vs. Starting New
If you’re already wearing Invisalign when you become pregnant, there’s typically no medical reason to stop. Let your orthodontist know so they can monitor your gum health more closely and adjust the treatment pace if needed. Some providers slow down tray changes or build in longer intervals between sets to account for increased tooth mobility and gum sensitivity.
If you’re thinking about starting Invisalign and are pregnant or actively trying to conceive, many orthodontists suggest waiting until after delivery. This isn’t because the aligners themselves are dangerous. It’s because pregnancy introduces so many variables (nausea, snacking patterns, gum inflammation, potential pauses in treatment) that the process becomes less predictable and more frustrating. Starting after delivery, or even after the postpartum period when hormones have stabilized, tends to produce a smoother experience with fewer interruptions.