The nanoparticles (NP) are defined as particles whose size is no greater than 100 nanometers. However, their impact on health remains little evaluated.

Placental transfer of NP has been proven in many studies in vitro and in vivo in animals, and toxicity in the fetus has been studied in many animals. The investigators seem interesting at first to establish the mineralogical load in the amniotic fluid in humans.

The first objective of this study is to determine the mineralogical NP load, quantity and composition, in the amniotic fluid in pregnant women.

The analysis will be done on 100 amniotic fluid samples and 100 blood samples. Particle size analysis will be performed by a technique of dynamic light scattering, which permits the distribution by volume or by number of NP according to their size. Parallel to the different chemical species present in the sample must be measured by atomic emission spectrometry with inductively coupled plasma.

The results of this study will be useful for further studies on the fetal toxicity of NP in humans.

Inclusion Criteria:

• Patient major
• Patient to receive an amniocentesis for medical reasons other than study (serum marker of the first quarter with an increased risk of trisomy 21 greater than 1/250, amniodrainage, sonographic sign of call)
• Patient who have given their free, informed and signed

Exclusion Criteria:

• Inability to make withdrawals

Pregnant women who receive an amniocentesis for medical reasons other than study