GuidePeriodontics

Gum Disease and Pregnancy Complications: What the Research Shows

Research has identified an association between gum disease (periodontitis) during pregnancy and adverse outcomes including preterm birth and low birth weight. While the evidence does not prove that gum disease directly causes these complications, the link is strong enough that dental and medical organizations recommend maintaining good periodontal health before and during pregnancy.

6 min readMedically reviewed contentLast updated March 20, 2026

Key Takeaways

Multiple studies have found that pregnant women with periodontitis have a higher risk of preterm birth (before 37 weeks) and low birth weight babies compared to women with healthy gums.
The association is well-documented, but researchers have not proven that gum disease directly causes pregnancy complications. The relationship may involve shared risk factors or inflammatory pathways.
Two biological mechanisms have been proposed: bacterial translocation (oral bacteria entering the bloodstream and reaching the placenta) and the inflammatory mediator pathway (gum disease triggering systemic inflammation that affects pregnancy).
Dental cleanings and scaling and root planing are considered safe during pregnancy, including during the second trimester. The ADA and ACOG both support necessary dental treatment during pregnancy.
Pregnancy itself can worsen existing gum disease due to hormonal changes that increase gum inflammation, a condition known as pregnancy gingivitis.
The best time to address periodontal problems is before becoming pregnant. If gum disease is identified during pregnancy, treatment should not be delayed.

The Link Between Gum Disease and Pregnancy Outcomes

Researchers have studied the relationship between periodontal disease and pregnancy complications for over two decades. The initial landmark study, published in 1996 in the Journal of Periodontology, found that pregnant women with periodontitis were more than seven times as likely to deliver a preterm, low birth weight baby compared to women with healthy gums.^[1] Since then, numerous studies and systematic reviews have examined this association.

The current scientific consensus recognizes a statistical association between periodontitis and adverse pregnancy outcomes, particularly preterm birth (delivery before 37 weeks of gestation) and low birth weight (below 2,500 grams). However, researchers are careful to distinguish between association and causation. Many factors influence pregnancy outcomes, and gum disease may be one contributing factor rather than a direct cause.

Understanding what the evidence does and does not show can help you make informed decisions about dental care during pregnancy. The good news is that periodontal treatment during pregnancy is safe and may reduce the risk of complications.

How Gum Disease May Affect Pregnancy: Two Proposed Pathways

Scientists have proposed two primary biological mechanisms to explain how gum disease in the mouth could influence pregnancy outcomes in the uterus. Both pathways involve the spread of bacteria or inflammatory signals from the infected gums to other parts of the body.

Bacterial Translocation Hypothesis

Periodontitis creates deep pockets between the teeth and gums where bacteria thrive. These pockets have a rich blood supply, and everyday activities like chewing and brushing can push bacteria from the infected gum tissue into the bloodstream. This process is called bacteremia.

The bacterial translocation hypothesis proposes that oral bacteria, particularly species like Fusobacterium nucleatum and Porphyromonas gingivalis, travel through the bloodstream and colonize the placenta or amniotic fluid. Studies have detected these oral bacteria in placental tissue and amniotic fluid of women who experienced preterm birth.^[2] If these bacteria trigger an immune response in the uterine environment, they could contribute to premature labor.

Inflammatory Mediator Pathway

The inflammatory mediator pathway suggests that the chronic inflammation caused by gum disease raises the levels of inflammatory chemicals (cytokines and prostaglandins) throughout the body, not just in the mouth. Prostaglandin E2, for example, is one of the chemical signals that triggers labor contractions.

In this model, the ongoing periodontal infection keeps the body in a state of low-grade systemic inflammation. Elevated levels of inflammatory mediators like interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) have been measured in pregnant women with periodontitis.^[3] If these levels rise high enough, they may contribute to premature cervical ripening and early labor.

What the Evidence Actually Shows

The evidence on gum disease and pregnancy complications is mixed in an important way. Observational studies consistently find an association. Intervention studies, which test whether treating gum disease during pregnancy reduces adverse outcomes, have produced less clear results.

A 2013 Cochrane systematic review examined randomized controlled trials that treated periodontal disease during pregnancy and measured birth outcomes. The review concluded that while periodontal treatment reduced gingivitis and periodontitis, there was insufficient evidence to determine whether treatment reduced the rates of preterm birth or low birth weight.^[4] A subsequent large multicenter trial (the OPT study) similarly found that treating periodontitis in pregnant women did not significantly reduce preterm birth rates.^[5]

This does not mean that gum disease is unrelated to pregnancy complications. It may mean that treatment during pregnancy comes too late to reverse the systemic effects that developed earlier. It may also mean that gum disease is a marker for other risk factors (such as smoking, socioeconomic status, or chronic stress) that independently contribute to adverse outcomes.

What the evidence does support is that untreated periodontitis during pregnancy is associated with higher risk, and that treating gum disease is safe during pregnancy and beneficial for the mother's oral health regardless of the pregnancy outcome effect.

Safe Dental Treatment During Pregnancy

Both the American Dental Association (ADA) and the American College of Obstetricians and Gynecologists (ACOG) affirm that dental treatment during pregnancy is safe and should not be postponed when needed.^[6] Delaying necessary treatment can allow infections to worsen, which poses a greater risk than the treatment itself.

The second trimester (weeks 14 to 27) is generally considered the most comfortable time for dental procedures, but urgent treatment can be performed during any trimester. Routine cleanings, scaling and root planing (deep cleaning), cavity fillings, and extractions when necessary are all considered safe.

Procedures Considered Safe During Pregnancy

Routine dental cleanings (prophylaxis) and periodontal maintenance visits.
Scaling and root planing for active gum disease. Local anesthesia (lidocaine with epinephrine) is considered safe at standard dental doses.
Dental X-rays when clinically necessary, with proper shielding. The radiation dose from dental X-rays is extremely low.
Cavity fillings and crown placement.
Emergency extractions and treatment of dental infections.

Precautions and Considerations

Inform your periodontist and dental team that you are pregnant. They may adjust the timing of elective procedures and select medications that are safest during pregnancy. Acetaminophen is preferred over ibuprofen for pain management during pregnancy. Certain antibiotics, such as amoxicillin, are considered safe, while others, such as tetracyclines, are avoided.

If you have a high-risk pregnancy or medical complications, your periodontist may coordinate with your obstetrician before scheduling treatment. This coordination ensures that both your dental and pregnancy care teams are aligned.

Pregnancy Gingivitis: Why Gum Problems Increase During Pregnancy

Hormonal changes during pregnancy, particularly increased progesterone levels, make the gums more sensitive to the bacteria in dental plaque. This leads to a condition known as pregnancy gingivitis, which affects an estimated 60% to 75% of pregnant women.^[7]

Pregnancy gingivitis typically appears in the second or third month of pregnancy and may worsen through the third trimester. Symptoms include gums that are red, swollen, tender, and bleed easily during brushing or flossing. In most cases, pregnancy gingivitis resolves after delivery as hormone levels return to normal.

However, if you have pre-existing periodontitis, pregnancy can accelerate the disease. The hormonal changes do not cause periodontitis on their own, but they amplify the inflammatory response to bacteria that are already present. This is one reason why addressing gum disease before pregnancy is ideal.

When to See a Periodontist During or Before Pregnancy

A periodontist is a dental specialist with advanced training in the prevention, diagnosis, and treatment of gum disease. If you are planning a pregnancy and have a history of gum problems, seeing a periodontist before conception allows you to address any active disease and establish a maintenance plan.

During pregnancy, see a periodontist if you notice bleeding gums that do not improve with better brushing and flossing, gums that are significantly swollen or painful, loose teeth, or persistent bad breath. Your general dentist can also refer you if they identify signs of periodontitis during a routine visit. Learn more about [periodontal care](/specialties/periodontics) and how a periodontist can help protect both your oral and overall health.

Find a Periodontist Near You

Every periodontist on My Specialty Dentist has verified specialty credentials. Search by location to find board-certified periodontists in your area who can evaluate your gum health and provide safe treatment during pregnancy.

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Frequently Asked Questions

Can gum disease cause a miscarriage?

Some studies have found an association between severe periodontitis and increased miscarriage risk, but the evidence is limited and a direct causal link has not been established. Many factors contribute to miscarriage risk. If you have gum disease and are pregnant or planning to become pregnant, treating it is recommended for your overall health.

Is it safe to get a deep cleaning while pregnant?

Yes. Both the ADA and ACOG support scaling and root planing during pregnancy when clinically indicated. The local anesthesia used (typically lidocaine with epinephrine) is considered safe at standard dental doses. Leaving active gum disease untreated poses a greater risk than the treatment itself.

Does treating gum disease during pregnancy prevent preterm birth?

The evidence is inconclusive. While some studies have shown a reduction in preterm birth rates after periodontal treatment, large randomized controlled trials and systematic reviews have not found a statistically significant effect. Treating gum disease during pregnancy is still recommended because it improves the mother's oral health and may reduce systemic inflammation.

When is the best time to see a dentist during pregnancy?

Dental visits are safe throughout pregnancy. The second trimester (weeks 14 to 27) is often the most comfortable for longer procedures. However, urgent dental treatment should not be delayed regardless of the trimester. Routine cleanings can be scheduled at any time during pregnancy.

Does pregnancy make gum disease worse?

Pregnancy does not cause gum disease, but the hormonal changes (particularly increased progesterone) amplify the gum tissue's inflammatory response to bacteria. This can worsen existing gingivitis or periodontitis. An estimated 60% to 75% of pregnant women experience some degree of pregnancy gingivitis, which typically resolves after delivery.

Should I see a periodontist before getting pregnant?

If you have a history of gum disease, bleeding gums, or deep periodontal pockets, seeing a periodontist before conception is a good idea. Treating active disease before pregnancy gives you a healthier starting point and reduces the chance that hormonal changes will worsen your condition during pregnancy. Your periodontist can also set up a maintenance schedule to follow throughout the pregnancy.