Congenital Lyme Disease


Whilst patients and some researchers suspect various ways in which the Borrelia bacteria can be transmitted, so far the only proven methods are through tick bites, congenitally and, probably, via blood transfusions.

In this guest blog post, the published evidence is summarised.


There is some confusion surrounding the issue of congenital Lyme disease, as some patients and even medical practitioners are unaware that the disease is proven to be transmissible this way.

There have been 46 cases of congenital Lyme disease documented in peer-reviewed research papers and, in total to date, 161 cases confirmed by microscopy, antibody testing and/or culture of live Borrelia from fetal samples, recorded by doctors who specialise in treating patients with Lyme disease.

One of the reasons for the confusion is that the majority of the earlier documented cases, which span the last 32 years, focused on babies who died shortly after birth, who were stillborn or miscarried. These fetuses could be thoroughly examined at autopsy in a way which living newborn babies cannot, but this resulted in a misconception that babies with congenital Lyme disease would always be stillborn. There are plenty of documented cases, however, which make it clear that this is not always the case.



The medical evidence concentrates on the most severe cases of gestational Lyme disease and this should not cause undue fear among expectant mothers suffering from the disease.

Pediatrician Dr. Charles Ray Jones and Dr. Richard Horowitz both report that out of the hundreds of patients they have seen, around two-thirds of mothers with Lyme disease who were not treated with antibiotics give birth to babies with congenital Lyme disease (and sometimes co-infections). However, 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.

Even more encouragingly, practitioners with clinical experience of treating mothers with Lyme disease, and the American Centers for Disease Control, 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.

If you have Lyme disease and are pregnant, you can make contact with some other women who have gone through Lyme disease pregnancies via the online patient support group Lyme Disease UK.


The public guidelines

Public Health England has no comment on this topic in its guidelines.

The Centers for Disease Control in America 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.”

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

“Untreated, Lyme disease can be dangerous to your unborn child. Lyme disease that goes untreated can also cause you to have brain, nerve, spinal cord, and heart problems. With early treatment, these complications can be prevented. No life-threatening effects on the fetus have been found in cases where the mother receives appropriate antibiotic treatment for her Lyme disease. In general, treatment for pregnant women is similar to that of non-pregnant adults, although certain antibiotics, such as doxycycline, are not used because they can affect fetal development.”
The ILADS treatment guidelines do not refer to Lyme disease in pregnancy.

Dr. Joseph Burrascano, who wrote Lyme disease and co-infection treatment guidelines, which summarises hundreds of peer-reviewed research papers, mentions the antibiotics recommended 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.”

Dr. Richard Horowitz states the following:

  • “I have had women who have had multiple miscarriages secondary to Lyme, where both the placenta and fetus showed evidence of infection…
  • Other tick-borne infections, such as the relapsing fever spirochete, as well as Babesia and Bartonella can also be transmitted to the fetus….
  • There are many scientific articles proving that Lyme can both harm and kill a developing fetus.”

The summary of outcomes in documented cases of congenital Lyme disease is as follows:

  • In mothers with active Lyme Disease,
    • Treated: 14.6% of the pregnancies involved symptoms in fetus (including fatality)
    • Untreated: 66.7% of the pregnancies involved symptoms in fetus (including fatality)
    • Unknown as to treatment: 30.3% involved symptoms in fetus (including fatality)
  • Specific adverse outcomes included:
    • cardiac 22.7%,
    • neurological 15.2%,
    • orthopedic 12.1%,
    • ophthalmic 4.5%,
    • genitourinary 10.6%,
    • miscellaneous anomalies 12.1%,
    • 2nd trimester miscarriage 12.1%.
  • Highest rate of adverse outcome (72.7%) in women with infection acquired prior to or during first trimester.

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 glaring 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 is flawed because there is no autopsy data on the 12 miscarriages. In the 11 seronegative mothers who miscarried, Lyme disease may have been present and may have caused defective fetuses.

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 major flaw in this research is the assumption that babies born with congenital Lyme disease are seropositive. This has been disproved by Dr. Alan MacDonald. 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.
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  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
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  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.
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