Termination of pregnancy is usually recommended to pregnant women who
have infection with Toxoplasma gondii before 26 weeks of pregnancy if
the fetus is infected. No prospective studies are available on the out
come if such pregnancies are allowed to continue with anti-parasitic t
reatment. We prospectively studied 163 mothers with acute toxoplasma i
nfection before 28 weeks of amenorrhoea. All received anti-parasitic t
reatment with 9 million IU spiramycin orally. 23 also received pyrimet
hamine and sulphadiazine. All had cordocentesis and regular obstetric
ultrasound examinations. The 162 liveborn infants were followed up for
15 to 71 months. 3 fetuses died in utero. 27 of 162 liveborn infants
had proven congenital toxoplasmosis: 10 had one or more clinical signs
of congenital toxoplasmosis; 5 had isolated or multiple intracranial
calcifications; 7 had peripheral chorioretinitis; and 2 had moderate v
entricular dilations. All 27 are free from symptoms and have normal ne
urological development at 15 to 71 months of age. We conclude that in
first and second trimester pregnancies with acute fetal toxoplasma inf
ection, the pregnancy need not be interrupted if repeated fetal ultras
ound is normal, and antiparasitic treatment is given.