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Congenital Lyme Disease

US CDC Guidance

Congenital transmission of Lyme disease was first acknowledged by the US Centers for Disease Control in a communication from 1985 where they stated "Transplacental transmission of B. burgdorferi has been documented in a pregnant woman with Lyme disease who did not receive antimicrobial therapy”:

Current Trends Update: Lyme Disease and Cases Occurring during Pregnancy -- United States. MMWR Weekly, June 28, 1985. 34(25);376-8,383-4.

In it, they reference research by Schlesinger et al:

Schlesinger PA, Duray PH, Burke BA, Steere AC, Stillman MT. Maternal-fetal transmission of the Lyme disease spirochete, Borrelia burgdorferi. Ann Intern Med. 1985;103(1):67-8.


In January 2020, the CDC altered their guidance to indicate that there could be vertical transmission with negative consequences for the fetus, stating "Lyme disease acquired during pregnancy may lead to infection of the placenta and possible stillbirth. Therefore, early diagnosis and treatment of Lyme disease is important during pregnancy. However, no negative effects on the fetus have been found when the mother receives appropriate antibiotic treatment."
LYME DISEASE: What you need to know. US Department of Health and Human Services, Centers for Disease Control and Prevention.


A number of other CDC documents now include information accepting that Lyme disease can be transmitted from mother to child during childbirth.

They state 'Untreated Lyme disease during pregnancy can lead to infection of the placenta. Spread from mother to fetus is possible but rare. Fortunately, with appropriate antibiotic treatment, there is no increased risk of adverse birth outcomes *. There are no published studies assessing developmental outcomes of children whose mothers acquired Lyme disease during pregnancy.'

* Silver HM. Lyme disease during pregnancy . Infect Dis Clin North Am. 1997 Mar;11(1):93-7.

The change of guidance followed a systematic review of the subject:
Waddell LA, Greig J, Lindsay LR, Hinckley AF, Ogden NH. A systematic review on the impact of gestational Lyme disease in humans on the fetus and newborn. PLoS One. 2018 Nov 12;13(11):e0207067.

Although the review stated "Only one case (in Germany) described the full range of expected observations (clinical manifestations in the mother, negative outcome for the child, and laboratory detection of B. burgdorferi in the child) that would give confidence that vertical transmission of B. burgdorferi, with negative consequences for the fetus, occurs”, as the review was co-authored by the CDC and the CDC guidance was changed shortly after its publication, it was clearly enough to persuade them to change their opinion.


The specific studies quoted in the review are:

  • Weber K, Bratzke HJ, Neubert U, Wilske B, Duray PH. Borrelia burgdorferi in a newborn despite oral penicillin for Lyme borreliosis during pregnancy. The Pediatric Infectious Disease Journal. 1988;7(4):286-9.

  • Weber K, Neubert U. Clinical features of early erythema migrans disease and related disorders. Zentralbl Bakteriol Mikrobiol Hyg A. 1986;263(1-2):209‐228.

In May 2021 a complaint was made to IDSA about a document on their website which contained an inaccurate statement that “Lyme disease is caused by bacteria called Borrelia burgdorferi that is only transmitted to humans when they are bitten by an infected tick”. In response, IDSA removed the publication from its website in June 2021.


NICE Guidance

In the NICE guidelines on Lyme disease, they state "The committee acknowledged that mother-to-baby transmission of Lyme disease is possible in theory. There was an absence of evidence, but the risk appears to be very low."

However, NICE reviewed congenital transmission only through observational studies that report an incidence or prevalence estimate of Lyme disease through vertical transmission.

No use was made of: in-vitro or animal studies; studies published in languages other than English; studies published after 3 July 2017; studies from non-OECD countries; or any case studies. In doing so, they reviewed only a very limited set of evidence involving only 12 documents. NICE’s literature search did not identify the study by Weber and Neubert above and by specifically excluding case studies they excluded the research by Schlesinger and Neubert et al. As a result, they did not review any of the research which has persuaded the CDC to change their guidance.

Further Information

An overview of congenital Lyme provides a very useful summary with further references supporting congenital transmission. The Research section of this site provides other useful references.

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