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Can Babies Be Born With Lyme Disease? Pregnancy Risks

Can Lyme disease be passed from mother to baby?
What research says about congenital Lyme disease
Why prompt diagnosis and treatment during pregnancy matter

Can babies be born with Lyme disease? Transmission of Lyme disease from an infected mother to her baby may be possible, but congenital Lyme disease remains incompletely understood. Published case reports and observational studies have identified possible transmission in some pregnancies, but the overall frequency, clinical significance, and long-term effects remain uncertain.

Researchers continue to investigate whether Lyme disease during pregnancy is associated with complications affecting the mother, pregnancy, newborn, or child. Available evidence suggests that prompt recognition and appropriate antibiotic treatment during pregnancy may reduce certain risks, although large prospective studies are still needed.

To explore these questions, investigators conducted an international cross-sectional survey comparing pregnancy and childhood outcomes among women with diagnosed Lyme disease, suspected Lyme disease, and no evidence of Lyme disease.

Participants were recruited primarily through Lyme disease-focused organizations, although eligibility was open to anyone over 18 years of age who had been pregnant. The study included women diagnosed before or during pregnancy, women whose symptoms were not diagnosed or treated until years later, and women who developed Lyme disease after pregnancy.

Investigators classified pregnancies according to whether there was probable treated Lyme disease, probable untreated Lyme disease, possible untreated Lyme disease, no evidence of Lyme disease, or insufficient information to determine Lyme disease status.

Only 45% of participants with diagnosed Lyme disease and 61% of those with suspected Lyme disease recalled a tick bite, while fewer than 40% remembered an erythema migrans (EM) rash, the authors reported.

Women considered likely to have had Lyme disease during pregnancy were more likely to report extreme fatigue, joint pain, fever of unknown origin, and postpartum depression than participants whose pregnancies showed no evidence of Lyme disease. However, the investigators could not determine whether these complications were related to Lyme disease, pregnancy itself, or other factors.

Children born following pregnancies classified as probably or possibly affected by Lyme disease did not differ significantly in gestational age at delivery, rates of intrauterine growth restriction, congenital anomalies, or hyperbilirubinemia compared with children born following pregnancies without evidence of Lyme disease.

However, the investigators reported associations with a broad range of childhood health conditions involving the musculoskeletal, gastrointestinal, cardiovascular, respiratory, neurologic, sensory, vision, skin, and sleep systems. Concentration difficulties and unexplained fevers were also reported more often in some Lyme disease-affected groups.

The authors emphasized that this observational study could not establish that Lyme disease during pregnancy caused these childhood conditions. Other explanations could include genetic factors, illnesses acquired after birth, differences between participant groups, or recall and selection bias.

The study had several important limitations. Participants were recruited primarily through North American Lyme disease advocacy organizations, creating the potential for selection bias. Many pregnancies occurred 10 to 70 years before the survey, increasing the possibility of recall bias. The children also differed in age across the study groups, which made comparisons of long-term health outcomes more difficult.

In addition, fetal, placental, cord blood, or other newborn tissues were reportedly tested for evidence of Borrelia burgdorferi following only 3% of pregnancies considered at risk for transmission. This limited the investigators’ ability to confirm whether congenital transmission had occurred.

Because this was a cross-sectional survey, it could identify associations but could not establish cause and effect. The findings should therefore be considered hypothesis-generating rather than proof that Lyme disease caused the reported pregnancy or childhood outcomes.

Despite these limitations, the investigators concluded, “This survey provides an important foundation upon which hypotheses can be generated for many overdue projects focused on Lyme disease in pregnancy.”

The authors also reported that treatment before or during pregnancy was associated with lower rates of certain neonatal findings, including rash, hypotonia, and respiratory distress. They wrote that their results supported the hypothesis that treatment “can attenuate severe pathology in neonates/children but does not eliminate poor outcomes entirely.”

A large U.S. surveillance study by investigators from the Centers for Disease Control and Prevention (CDC) provides additional context. Researchers reviewed 698,876 reported Lyme disease cases from 1992 through 2019 and identified 643 cases reported during pregnancy.

Among reported Lyme disease cases, pregnant women were more likely than non-pregnant women of reproductive age to have early localized disease presenting only with an erythema migrans rash. The authors suggested that this pattern could reflect earlier detection because pregnant women have more frequent contact with healthcare professionals or may seek evaluation sooner.

Because the study relied on surveillance reports, the finding that pregnancy-associated cases were uncommon does not establish the true frequency of Lyme disease during pregnancy. Cases that were not diagnosed, not reported, or lacked documented pregnancy status would not have been fully captured.

The CDC investigators concluded that prompt antimicrobial treatment is critical for preventing severe Lyme disease and reducing the risk of adverse pregnancy or birth outcomes.

Together, these studies highlight the importance of early recognition and appropriate treatment during pregnancy while underscoring the need for prospective research to better define the frequency and clinical significance of congenital Lyme disease.

Frequently Asked Questions

Can Lyme disease be passed from mother to baby?

Transmission of Borrelia burgdorferi from an infected mother to her baby may occur in some pregnancies. However, congenital Lyme disease remains an area of ongoing research, and its overall frequency and clinical significance have not been clearly established.

Can babies be born with Lyme disease?

Published case reports have described evidence of Borrelia burgdorferi in placental or fetal tissues, suggesting that transmission may be biologically possible. However, tissue testing has rarely been performed consistently, and researchers have not identified a well-defined syndrome that occurs in every affected baby.

Does treating Lyme disease during pregnancy reduce the risk?

Observational studies, CDC surveillance data, and systematic reviews suggest that appropriate antibiotic treatment during pregnancy is associated with better outcomes than untreated Lyme disease. In the international survey, treatment was associated with lower reported rates of certain neonatal findings, including rash, hypotonia, and respiratory distress. Additional prospective studies are needed.

Does every pregnant woman with Lyme disease have an affected baby?

No. Many women with Lyme disease during pregnancy deliver healthy infants. The available studies do not show that every maternal infection results in transmission or adverse pregnancy outcomes.

What should a pregnant woman do if Lyme disease is suspected?

A pregnant woman with a tick bite, erythema migrans rash, facial weakness, unexplained neurologic symptoms, joint swelling, heart symptoms, or other signs of Lyme disease should seek prompt medical evaluation. Treatment decisions should be individualized based on the clinical presentation, pregnancy, medication safety, and other relevant medical factors.

Clinical Takeaway

Whether Lyme disease can be transmitted during pregnancy remains an area of active investigation. The available evidence comes primarily from observational studies, surveillance data, systematic reviews, and case reports, each with important strengths and limitations.

The international survey found associations between pregnancies considered affected by Lyme disease and several maternal, neonatal, and childhood health findings. However, its retrospective design, participant recruitment, differences between study groups, and limited testing of fetal or newborn tissues prevent it from establishing causation or confirming congenital infection in most cases.

U.S. surveillance data show that reported Lyme disease cases during pregnancy more commonly involved early manifestations, which may reflect earlier recognition and treatment. However, determining the true frequency of Lyme disease during pregnancy or possible congenital transmission remains challenging. Surveillance depends on cases being recognized, accurately diagnosed, and reported, while early Lyme disease testing may be negative and confirmatory testing of placental, fetal, or newborn tissues is performed infrequently.

Although congenital Lyme disease remains incompletely understood, early diagnosis and appropriate antibiotic treatment during pregnancy remain the best-supported strategies for reducing potential risks to both mother and baby while additional prospective studies are conducted.

Related Articles

Case series: No complications with Lyme disease and pregnancy
Can Lyme disease impact pregnancy outcomes?
Mother describes challenges in getting treatment for newborn with Lyme disease

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention