Pregnancy and Lyme disease

If a woman is bitten by a deer tick or contracts Lyme disease while pregnant, it’s important that she immediately alert her treating physician. There have been poor outcomes described for newborns whose mothers contracted Lyme disease during pregnancy.

If a woman is bitten by a deer tick while pregnant, it’s important that she immediately alert her treating physician.

Studies have found that stillbirths occurred when the disease was contracted during the first trimester.[1-3] Gestational Lyme borreliosis has been described in 5 of 19 pregnancies (26%) resulting in “syndactyly, cortical blindness, intrauterine fetal death, prematurity, and rash.”[1]

Another report attributes an infant’s death, at one week old, to a vertical transmission of Bb from the mother, after the autopsy showed evidence of spirochetes in the spleen, kidneys, and bone marrow.[2] Another newborn died, at 39 hours of life, with a left-sided hypoplastic heart and the presence of spirochetes consistent with Bb “in the spleen, kidneys, and bone marrow.”[2] Bb has also been cultured from fetal liver tissue in 4 stillborn infants.[4]

MacDonald et al. has described Lyme disease newborns with “hydrocephalus, cardiovascular anomalies, neonatal respiratory distress, hyperbilirubinemia, intrauterine growth retardation, cortical blindness, sudden infant death syndrome, and maternal toxemia of pregnancy.”[5] And, Bb was described in a newborn despite oral penicillin for Lyme borreliosis during pregnancy.[6]

There is insufficient evidence to determine the risk to the child if the mother contracted Lyme disease before pregnancy.[7] A study of 2,000 women with a history of Lyme disease did not demonstrate an increased risk of fetal death, decreased birth weight, or length of gestation at delivery.[8] In the same study of 2,000 women, a history of a tick bite within 3 years of conception was associated with congenital defects. [8]

A subsequent study of 5,000 women demonstrated a significantly higher incidence of cardiac malformations but not a higher total incidence of congenital malformations.[9] A follow-up case control study of 796 children via a mail survey did not show an association between maternal Lyme disease and birth defects.[10]

Choosing an antibiotic regimen for pregnant women with Lyme disease can be a complex challenge. Amoxicillin, cefuroxime, azithromycin, and IV ceftriaxone have been prescribed for pregnant women.[11,12]

Breastfeeding

There is insufficient data to determine if breastfeeding can transmit Bb to the child. Certain antibiotic classes, such as the tetracyclines, should not be used in women being treated for Lyme disease who are breastfeeding to avoid the risk of side effects, such as teeth discoloration. The child’s clinician can help guide treatment options for a breastfeeding mother.