Erythema migrans in pregnancy

From 1990 through to 1997, 105 pregnant women with typical EM were investig ated at the Lyme Borreliosis Outpatients' Clinic of the Department of Infec tious Diseases at the University Medical Centre in Ljubljana, Slovenia. Twe nty-five (23.8%) patients acquired borrelial infection during the first tri mester of pregnancy; eight (7.6%) of them had noticed the skin lesion befor e they became pregnant. In 43 (40.6%) patients the EM appeared in the secon d trimester, and in 37 (35%) patients in the third trimester of pregnancy. Two (1.9%) patients received phenoxymethyl penicillin (1 million IU t.i.d.) , three (2.9%) benzyl penicillin (10 million IU b.i.d.), and 100 (95.2%) ce ftriaxone (2 g daily). All patients were treated for 14 days except three ( 2.9%) in whom the treatment with ceftriaxone was discontinued because of mi ld side effects. The outcome of disease was good in all 105 patients. Ninet y-three (88.6%) out of 105 patients had normal pregnancies; the infants wer e delivered at term, were clinically healthy, and subsequently had a normal psychomotor development. In the remaining 12 (11.4%) patients an adverse o utcome was observed. Two (1.9%) pregnancies ended with an abortion (one mis sed abortion at 9 weeks, one spontaneous abortion at 10 weeks), and six (5. 7%) with preterm birth. One of the preterm babies had cardiac abnormalities and two died shortly after birth. Four (3.8%) babies born at term were fou nd to have congenital anomalies: one had syndactyly at birth and three had urologic abnormalities which were registered at the age of 5, 7, and 10 mon ths, respectively. A causal association with borrelial infection was not pr oven in any infant. For at least some unfavourable outcomes a plausible exp lanation not associated with Lyme borreliosis was found.