Lyme Disease in pregnancy

DISCLAIMER: Caudwell LymeCo charity shares public domain  information, which it believes to be reliable, in good faith. It should never replace the advice of a qualified physician with a license to practise medicine. If you believe any information on this website to be incorrect, you are invited to contact the charity using the Contact page.

What is the effect of Lyme disease in a pregnant woman on the baby?

The NICE Guideline

The UK’s NICE Guideline for Lyme disease makes the following recommendations for treating pregnant women with Lyme disease (in sections 1.3.18 to 1.3.21):

  1. Full treatment of pregnant women is very important. There are antibiotics to treat Lyme disease which are safe for unborn babies. (This will be amoxycillin rather than doxycycline, and in the published research reviewed by the guideline committee the evidence suggested it is just as effective to treat Lyme disease as doxycycline.)
  2. There is not conclusive evidence on the probability of risk to the baby, which means a percentage risk cannotbe calculated, but it is thought that the likelihood of a mother passing Lyme disease to her unborn baby is low.
  3. If the mother notices anything that could give cause for concern about the baby’s health, the new-born baby should be referred to a paediatric infectious diseases consultant to discuss which Lyme disease tests are appropriate.
  4. Babies born to mothers with Lyme disease should be treated for Lyme disease under the care of a specialist, if their Lyme test has a positive result, or if there is any other reason to suspect they may have Lyme disease.

International advice on Lyme disease in pregnancy

The Centers for Disease Control and Prevention (CDC) in America has also addressed the question of Lyme disease in pregnancy, and the possible effects upon the unborn baby. It has the following advice:

“Lyme disease acquired during pregnancy may lead to infection of the placenta and possible stillbirth; however, no negative effects on the fetus have been found when the mother receives appropriate antibiotic treatment.”

Link to source: CDC Lyme FAQ

Its patient advice leaflet for pregnant mothers, here, gives the following information:

“Untreated Lyme disease during pregnancy may lead to infection of the placenta and possible stillbirth. Fortunately, no serious effects on the fetus have been found in cases where the mother receives appropriate antibiotic treatment. In general, treatment for pregnant women with Lyme disease is similar to that of non-pregnant adults, although certain antibiotics, such as doxycycline, are not used because they can affect fetal development. There are no reports of Lyme disease transmission from breast milk. There are no published studies assessing developmental outcomes of children whose mothers acquired Lyme disease during pregnancy.”

Link to source: Pregnancy and Lyme Disease

FAQ on Lyme disease in pregnancy

What evidence is there about the transmission of Lyme disease to unborn babies?

The probability of a pregnant woman’s Lyme disease either infecting or harming her baby is thought to be low. The only evidence available is circumstantial. No researcher would deliberately give pregnant women with Lyme disease no treatment, just to find out what happened. This means our information is written by doctors or scientists describing women whose Lyme disease did seem to harm their baby, and these examples cannot tell us Lyme disease was definitely the cause of their baby’s problems or how often this happens. The guideline errs on the side of caution and states that it is very important for pregnant women to receive full treatment, because the nature of the risk is very serious.

There have been 46 cases of congenital Lyme disease documented in peer-reviewed research papers.

Source: Some of the research papers are listed at the bottom of this page.

These papers are case studies, meaning they report on individual examples of babies born to mothers with Lyme disease. They do not give us information on the outcome for a large group of mothers, which might indicate how likely a mother would be to transmit the disease to her baby. Therefore we do not know if pregnant women with untreated Lyme disease are highly likely to transmit the disease to their baby, or if it happens extremely rarely; we simply know that it can happen.

Do babies born with Lyme disease always die?

The majority of documented cases of gestational Lyme disease focused on babies who died shortly after birth, who were stillborn or miscarried. It has not been established whether these deformities and deaths were actually caused by Lyme disease, or if Lyme disease was just an additional condition in these cases.

The reason the medical research papers focus on dead foetuses and babies is that their organs and tissues could be thoroughly examined at autopsy. Not many mothers want to permit multiple biopsies and blood tests to be performed on their new born baby simply for research, so the same type of research on living and healthy babies – which might balance the picture – has not been carried out.

The medical evidence, therefore, should not cause undue fear among expectant mothers suffering from Lyme disease. It does not necessarily mean that a mother with untreated Lyme disease will lose her baby.

Is there evidence of more positive outcomes?

The CDC patient advice states that no life-threatening effects on the baby have been found in mothers who are given suitable antibiotic treatment for their Lyme disease during pregnancy.

There are some doctors in the USA who have treated numbers of patients with Lyme disease who have offered additional anecdotal evidence. They agree that mothers given adequate antibiotic treatment for Lyme disease during pregnancy are unlikely to give birth to a child infected with, or affected by, Lyme disease.

What if the mother receives no antibiotic treatment?

We have heard anecdotal reports from some doctors who treat large numbers of patients with Lyme disease. Some of them report that around two-thirds of mothers with Lyme disease who were not treated with antibiotics gave birth to babies with congenital Lyme disease. However, they say, very rarely does this result in the death of the baby or the severe, life-threatening symptoms and deformations reported in the peer-reviewed medical research. These doctors have claimed that one third of the babies were born without Lyme disease or any health problems, even when the mother had no antibiotic treatment during pregnancy.

Please note, that this is an anecdotal observation and has not been verified or proven in objective research projects. It is offered merely as the opinion of a few observers.

What other advice do doctors offer?

One doctor, Dr. Joseph Burrascano, writes his own set of Lyme disease and co-infection treatment guidelines. These are not “official” guidelines, but rather, a summary of his own advice based on clinical experience and research papers.

Link to source: Burrrascano treatment guidelines

He mentions the antibiotics he personally recommends to treat women with Lyme disease during pregnancy, to minimise the likelihood of transmission of the disease to the child.

“It is well known that B. burgdorferi can cross the placenta and infect the fetus. In addition, breast milk from infected mothers has been shown to harbor spirochetes that can be detected by PCR and grown in culture.

The Lyme Disease Foundation in Hartford, CT had kept a pregnancy registry for eleven years beginning in the late 1980s. They found that if patients were maintained on adequate doses of antibiotic therapy during gestation, then no babies were born with Lyme. My own experience over the last twenty years agrees with this.

The options for treating the mother include oral, intramuscular, and intravenous therapy as outlined above [refers to standard adult treatment protocols in the document found here]. It is vital that peak and trough antibiotic levels be measured if possible at the start of gestation and at least once more during treatment.

During pregnancy, symptoms generally are mild as the hormonal changes seem to mask many symptoms. However, post-partum, mothers have a rough time, with a sudden return of all their Lyme symptoms including profound fatigue. Post partum depression can be particularly severe. I always advise help in the home for at least the first month, so adequate rest and time for needed treatments are assured.

I also advise against breast feeding for obvious reasons as mentioned above.”

Is breastfeeding safe when the mother has Lyme disease?

The UK does not have official advice on this topic, that we are aware of. The CDC offers the following advice:

“There are no reports of Lyme disease being spread to infants through breast milk. If you are diagnosed with Lyme disease and are also breastfeeding, make sure that your doctor knows this so that he or she can prescribe an antibiotic that’s safe for use when breastfeeding.”

Link to source: CDC Lyme Disease FAQ

We are aware that some doctors advise mothers against breastfeeding when they have Lyme disease.


A summary of some published research papers

The following is a bullet-point summary of some of the published research papers on Lyme disease in pregnancy. It is not the result of a systematic evidence review and should not be read as such. It should not be taken as a statement of Caudwell LymeCo’s position on this topic and should definitely not be taken as medical advice.

The first reported case of congenital Lyme was documented in 1985.

Maternal-fetal Transmission of the Lyme Disease Spirochete, Borrelia Burgdorferi, Annals of Internal Medicine 103:67-69, 1985, P.A. Schlesinger et al

  • Woman in Wisconsin, USA was bitten during her first trimester and developed EM and typical Lyme disease symptoms
  • Did not receive medical treatment
  • Gave birth to a baby boy at 35 weeks
  • Baby died 39 hours later from congestive heart failure
  • At autopsy there were several major defects of the heart
  • Lyme disease spirochetes were found in the baby’s spleen, kidneys, bone marrow and heart at autopsy.
  • The mother tested positive for Lyme disease after pregnancy

In 1986, a case was reported by Weber.

Weber, K, Bratzke, HJ, Neubert, U, Wilske, B, Duray, PH. Borrelia burgdorferi in a newborn despite oral penicillin for Lyme borreliosis during pregnancy. Pediatr Infect Dis J 1988; 7:286–289.

  • Mother bitten by multiple ticks during her first trimester
  • Developed EM rash several weeks later
  • Treated with a “standard” course of oral penicillin for seven days, three times a day
  • Baby delivered at term and appeared normal
  • During the next 23 hours the baby developed breathing problems and died
  • Autopsy showed brain hemorrhages
  • Spirochetes compatible with Borrelia burgdorferi in the brain and the liver
  • Mother’s blood initially tested negative for antibodies to the Lyme spirochete; at a later date her frozen blood tested positive for IgM antibodies using the ELISA test.

Another case was reported in 1987 in Utah.

Stillbirth following maternal Lyme disease, MacDonald AB, Benach JL, Burgdorfer W., N Y State J Med. 1987 Nov;87(11):615-6

  • Woman infected in her first trimester of pregnancy, but not diagnosed or treated
  • Had EM rash and joint swelling
  • Went into labour at full term
  • Baby’s heartbeat already undetectable, baby dead at birth
  • Autopsy revealed a hole in the wall of the heart which separates the two main pumping chambers
  • Lyme bacterium cultured from the baby’s liver, brain, heart, adrenal gland and placenta
  • Mother was tested for Lyme antibodies at three different laboratories and the result was positive from two of them. She tested negative for syphilis.

The medical report stated:

“Transmission of the spirochete Borrelia Burgdorferi from mother to fetus during the first trimester of pregnancy was followed by overwhelming spirochetosis in the fetus.”

Markowitz published a study of Lyme and pregnancy in 1986.

Markowitz LE, Steere AC, Benach JL, et al. Lyme disease during pregnancy. JAMA.(1986); 255(24), 3394-6

  • Nineteen patients infected during pregnancy
  • Five had adverse outcomes (one fetal death at 20 weeks, high bilirubin level in a four-week premature baby, webbed toes, blindness and developmental delay, and a newborn rash)
  • Thirteen of the nineteen had received antibiotics
  • Authors concluded that there was no proof that Lyme disease was responsible for the adverse outcomes since all of them were dissimilar
  • Consensus that this was an abnormally high frequency of adverse outcomes, and that pregnant women with diagnosed Lyme disease should be treated immediately with penicillin.

Williams and colleagues conducted a study in a Lyme-endemic area in New York of umbilical cord blood.

Williams, CL, Strobino, B, Weinstein, A, Spierling, P, Medici, F. Maternal Lyme disease and congenital malformations: a cord blood serosurvey in endemic and control areas. Paediatr Perinat Epidemiol 1995; 9:320–330

  • Of 255 infants tested, 10.2% had detectable antibody to the Lyme disease spirochete; Of 166 infants born in a non-endemic area, 2.4% had detectable antibodies
  • Birth defects did not differ significantly between the two groups
  • First group tended to be lower birth weight and smaller, with more jaundice
  • Authors concluded that these differences were not significant

A strange flaw in this study is that it only included live births. Since miscarriages, stillbirth and perinatal infant deaths were not included, the possibility of congenital defects possibly associated with Lyme and incompatible with life are not included.

Dr. Andrea Dlesk, of the Marshfield clinic in Wisconsin, studied 143 healthy pregnant women.

  • Lyme disease serologic tests were obtained on initial and postpartum visits
  • 116 women had completed their pregnancies and 12 had miscarried, one of whom tested positive
  • Of the 104 women who did not miscarry, 13 women tested positive for Lyme disease
  • Conclusion: healthy women who test positive for Lyme disease are at no increased risk for miscarriage

This study gives no autopsy data on the 12 miscarriages.

In 1988, Carlomango studied 49 women who had either a 1st or 2nd trimester spontaneous abortion.

Carlomagno G; Luksa V; Candussi G; Rizzi GM; Trevisan G Acta Eur Fertil 1988 Sep-Oct;19(5):279-81 Dept. of Obstetrics and Gynecology, University of Trieste School of Medicine. Lyme Borrelia positive serology associated with spontaneous abortion in an endemic Italian area.

  • Six (6) of them (12.2%) tested positive for Lyme disease
  • 3 of 49 women who delivered at term tested positive
  • Authors concluded that there was no statistical significance between the two groups.

In 1988, Nadal surveyed 1,416 women and their 1,434 infants at delivery for presence of antibodies to the Lyme disease spirochete.

Nadal, D, Hunziker, UA, Bucher, HU, Hitzig, WH, Duc, G. Infants born to mothers with antibodies against Borrelia burgdorferi at delivery. Eur J Pediatr 1989; 148:426–427.

  • Twelve women tested positive
  • Six had a history of pre-existing Lyme disease
  • Five had unremarkable histories
  • Of these twelve women, seven had remarkable outcomes:
    • Two had elevated bilirubinemia
    • One had muscle hypotonia (laxness)
    • One was post-term, small for age, and evidenced chronic placental insufficiency
    • One had transient macrocephaly (large head)
    • One had transient supraventricular extrasystoles (“skipped heart beats”)
    • The infant born of the mother with EM had a VSD-hole in the heart connecting the two main pumping chambers.
  • None of these babies had positive blood tests for antibodies to Lyme disease
  • Conclusion was that the adverse outcomes were not due to Lyme disease

A possible flaw in this research is the assumption that babies born with congenital Lyme disease are seropositive. In comparison, there is also seronegativity in babies with congenital syphilis.

In 1989, Dr. Alan MacDonald reported his findings in autopsies performed following perinatal deaths at Southampton Hospital between 1978 and 1988.

MacDonald, AB, Benach, JL, Burgdorfer, W. Stillbirth following maternal Lyme disease. NY State J Med 1987; 87:615–616

  • Routine pathology studies on tissues will not demonstrate the Lyme disease spirochete
  • Four cases where there was live birth and spirochetes were demonstrated in the placentas
  • No history or evidence of Lyme disease in the mothers, blood tests were negative in all but but one case
  • Spirochetes compatible with Borrelia burgdorferi were identified in the vital organs
  • Numerous developmental defects were observed.
  • Tissue inflammation not seen in fetuses with transplacentally acquired infection with the Lyme disease spirochete.
  • Lyme disease acquired in utero may result in fetal death in utero, fetal death at term or infant death after birth.
  • Babies may survive in spite of the bacteria being isolated in the placenta
  • In all but one case, where the Lyme disease organism was identified in the placenta or the fetal tissues, the maternal blood had no evidence of antibodies to the Lyme disease bacteria.

List of research papers

  1. MacDonald A. Gestational Lyme borreliosis. Implications for the fetus. Rheum Dis Clin North Am. 1989 Nov;15(4):657-77
  2. MacDonald AB, Benach JL, Burgdorfer W. Stillbirth following maternal Lyme disease. N Y State J Med. 1987Nov;87(11):615-6
  3. MacDonald A. Human fetal borreliosis, toxemia of pregnancy, and fetal death. Zentralbl Bakteriol Mikrobiol Hyg A.1986 Dec;263(1-2):189-200
  4. Markowitz LE, Steere AC, Benach JL, et al. Lyme disease during pregnancy. JAMA.(1986); 255(24), 3394-6
  5. Lavoie PE, Lattner BP, Duray PH, Barbour AG, Johnson HC. Culture positive seronegative transplacental Lyme borreliosis infant mortality. (1987) Arthritis Rheum, 30(4), 3(Suppl):S50
  6. Mikkelsen AL, Palle C. Lyme disease during pregnancy. (1987) Acta Obstet Gynecol Scand 66(5), 477-8
  7. Bale, J. F., Jr. and J. R. Murph (1992). “Congenital infections and the nervous system.” Pediatr Clin North Am 39(4): 669-90.
  8. Brzostek, T. (2004). “[Human granulocytic ehrlichiosis co-incident with Lyme borreliosis in pregnant woman—a case study].” Przegl Epidemiol 58(2): 289-94.
  9. Carlomagno G; Luksa V; Candussi G; Rizzi GM; Trevisan G Acta Eur Fertil 1988 Sep-Oct;19(5):279-81 Dept. of Obstetrics and Gynecology, University of Trieste School of Medicine. Lyme Borrelia positive serology associated with spontaneous abortion in an endemic Italian area.
  10. Gardner, T. (1995). Lyme disease. Infectious diseases of the fetus and newborn infant.J. S. Remington and J. 0. Klein. Philadelphia, Saunders. Chap. 11: 447-528.
  11. Goldenberg, R. L and C. Thompson (2003). “The infectious origins of stillbirth.” Am J Obstet Gynecol 189(3): 861-73.
  12. Gustafson, J. M., E. C. Burgess, et al. (1993). “Intrauterine transmission of Borrelia burgdorferi in dogs.” Am J Vet Res 54(6): 882-90. (dog study)
  13. Hercogova J, Vanousova D. (2008). Syphilis and borreliosis during pregnancy. Dermatol Ther. 2008 May-Jun;21(3):205-9.
  14. Lavoie PE;Lattner BP;Duray PH; Barbour AG; Johnson HC. Arthritis Rheum 1987; Culture positive seronegative transplacental Lyme borreliosis infant mortality. Volume 30, Number 4, 3(Suppl):S50.
  15. MacDonald, A. B. (1989). “Gestational Lyme borreliosis. Implications for the fetus.” Rheum Dis Clin North Am 15(4): 657-77.
  16. MacDonald, A. B. (1986). “Human fetal borreliosis, toxemia of pregnancy, and fetal death.”Zentralbl Bakteriol Mikrobiol Hyg [A] 263(1-2): 189-200.
  17. MacDonald, A. B., J. L. Benach, et al. (1987). “Stillbirth following maternal Lyme disease.” NYState J Med 87(11): 615-6.
  18. Maraspin, V., J. Cimperman, et al. (1999). “Erythema migrans in pregnancy.” Wien Klin Wochenschr 111(22 23): 933-40.
  19. Markowitz, L. E., A. C. Steere, et al. (1986). “Lyme disease during pregnancy.” Jama 255(24): 3394-6. Because the etiologic agent of Lyme disease is a spirochete, there has been concern about the effect of maternal Lyme disease on pregnancy outcome.
  20. Schlesinger, P. A., P. H. Duray, et al. (1985). “Maternal-fetal transmission of the Lyme disease spirochete, Borrelia burgdorferi.” Ann Intern Med 103(1): 67-8.
  21. Strobino BA, Abid S, Gewitz M (1999) Maternal Lyme disease and congenital heart disease: A case-control study in an endemic area. Am. J. Obstet. Gyn., 180 :711-716.
  22. Strobino BA, Williams CL, Abid S, Chalson R, Spierling P (1993) Lyme disease and pregnancy outcome: A prospective study of 2,000 prenatal patients. Amer J Ob Gyn, 169:367‑
  23. Walsh CA, Mayer EW, Baxi LV. (2007). Lyme disease in pregnancy: case report and review of the literature. Obstet Gynecol Surv. 2007 Jan;62(1):41-50.
  24. Williams CL, Strobino BA, Lee A, Curran A, Benach JL, Inamdar S and Cristofaro (1990) Lyme disease in childhood: Clinical and epidemiologic features of ninety cases. Pediatr. Infect. Dis., 9: 10‑
  25. Williams CL and Strobino BA (1990) Lyme disease and pregnancy ‑ A review of the literature. Contemporary Ob/Gyn, 35:48