Increased pregnancy weight gain in women with latent toxoplasmosis and RhD-positivity protection against this effect

Parasitology. 2010 Oct;137(12):1773-9. doi: 10.1017/S0031182010000661. Epub 2010 Jul 6.


Objective: RhD-positive subjects are protected against toxoplasmosis-associated impairment of psychomotor performance. Here we searched for RhD-positivity-associated maternal protection against the effects of toxoplasmosis.

Methods: In the present retrospective cohort study, we analysed data from 785 (139 RhD-negative) Toxoplasma-free and 194 (27 RhD-negative) Toxoplasma-infected pregnant women. We searched for effects of toxoplasmosis and Rhd-phenotype on maternal weight before pregnancy, pregnancy weight gain, fetal ultrasound data (biparietal diameter, abdominal circumference, femur length) and on birth length and weight.

Results: At pregnancy week 16, the RhD-negative mothers with toxoplasmosis gained more weight than others (P < 0.001). The difference of about 1600 g remained approximately constant from pregnancy week 16 until the end of pregnancy. Neither toxoplasmosis nor RhD phenotype had any effect on fetal bioparameter data or birth length and weight.

Conclusion: The most parsimonious explanation for the observed data is that the RhD-positive phenotype might protect infected subjects against a broad spectrum of detrimental effects of latent toxoplasmosis, including excessive gestational weight gain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Birth Weight
  • Body Weight
  • Female
  • Humans
  • Infant, Newborn
  • Pregnancy
  • Pregnancy Complications, Parasitic / blood
  • Pregnancy Complications, Parasitic / parasitology
  • Pregnancy Complications, Parasitic / physiopathology*
  • Rh-Hr Blood-Group System / blood*
  • Rh-Hr Blood-Group System / immunology
  • Toxoplasma
  • Toxoplasmosis / blood
  • Toxoplasmosis / parasitology
  • Toxoplasmosis / physiopathology*
  • Ultrasonography, Prenatal
  • Weight Gain*
  • Young Adult


  • Rh-Hr Blood-Group System
  • Rho(D) antigen