title: Congenital toxoplasmosis in twins: a report of fourteen consecutive cases and a comparison with published data.
abstract: BACKGROUND
  The combined influence of congenital toxoplasmosis and twin pregnancy on the duration of gestation has not been previously examined. Similarly little is known about the influence of genetic factors on the clinical course of this disease. The present study addresses these issues.
  
  
  METHODS
  Fourteen consecutive twin pairs born of mothers with Toxoplasma seroconversion during pregnancy were monitored after birth and during childhood, and the relevant data were compared with those already documented for similar cases.
  
  
  RESULTS
  The presumed time of gestation at which women became infected was earlier in noninfected than in infected twins (P = 0.007). Congenital infection did not influence the duration of pregnancy either in our own cases [36.2 +/- 4.3 weeks for noninfected children and 37.4 +/- 1.8 weeks for infected ones (P = 0.45)] or in previously published ones [35.4 +/- 3.6 weeks (P = 0.69)]. The infection status was identical for monozygotic twins (with one exception) but different for dizygotic ones (19 of 20 vs.35 of 45 cases). The clinical course through childhood corresponded more closely for monozygotic twins than for dizygotic ones [17 of 20 vs.20 of 45 cases (P = 0.007)].
  
  
  CONCLUSIONS
  Twin pregnancy is not a risk factor either for premature birth or for Toxoplasma infection in contaminated twins. The closely corresponding infection status between monozygotic twins highlights the crucial role played by the placenta in disease transmission. However, the substantial proportion of discrepant clinical courses suggests that other, as yet unknown, factors may be involved.
authors.affiliation: Service de Parasitologie, Hôpital de la Croix-Rousse, 103 Grande Rue de la Croix-Rousse, 69004 Lyon, France. francois.peyron@chu-lyon.fr
authors.forename: Francois
authors.initials: F
authors.lastname: Peyron
authors.forename: Athanase B
authors.initials: AB
authors.lastname: Ateba
authors.forename: Martine
authors.initials: M
authors.lastname: Wallon
authors.forename: Laurent
authors.initials: L
authors.lastname: Kodjikian
authors.forename: Christine
authors.initials: C
authors.lastname: Binquet
authors.forename: Jacques
authors.initials: J
authors.lastname: Fleury
authors.forename: Justus G
authors.initials: JG
authors.lastname: Garweg
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D011336:Probability; D012307:Risk Factors; D012494:Sampling Studies; D013557:Switzerland / Q000453:epidemiology; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis* / Q000453:epidemiology*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic