The effects of low-frequency magnetic fields (MFs) on early pregnancy
were studied in CBA/S mice. The magnetic field was a 20 kHz, 15 mu T s
awtooth. Pregnant females were divided into four groups, two control g
roups and two exposed groups. One group was exposed to MFs continuousl
y from day 1 postconception (pc) until day 5.5 pc, and the other group
was exposed continuously until day 7 pc. All animals were sacrificed
on day 19 pc, the day before partus, and their uterine contents were a
nalyzed. No significant increase in the resorption (early fetal death)
rate was found in the exposed animals compared to the sham controls.
In the group exposed during days 1.0-5.5 pc, the body weight and lengt
h of the living fetuses were significantly decreased. Except on day 3
pc (progesterone) and day 13 pc (calcium) in the treated groups, there
were no significant differences in progesterone and calcium levels in
peripheral blood. Implantation occurred on the same day in ME-treated
and control animals. (C) 1995 Wiley-Liss, Inc.