[Altitude and pregnancy. Apropos of an experimental study on the pregnant rat].
Pregnancies that occur at high altitude are bedevilled by many complications and particularly those due to pressure disorders. Although there are many maternal and placental mechanisms that are brought to bear to "blunt" the effects of hypoxia in the fetus, these pregnancies are characterised by low birth weights. This work has been carried out to find out the effects of hypoxia during part only of the pregnancy. The study was carried out on three groups of ten pregnant Wistar Rats: a control group with normal oxygenation (N); a group exposed to hypobaric hypoxia during the 4th to the 12th day of pregnancy (480 mmHg, equivalent to altitude of 5200 m) (HP); and a group exposed to the same levels of hypoxia between the 12th and 20th days of pregnancy (HT). The litters were the same size in each group. Mortality of the little rats respectively were 0%, 8.1% and 30.6% in groups N, HP and HT (p < 0.001). With hypoxia the rats eat less at whichever stage of pregnancy. Weight gain in pregnancy overall was less in the groups exposed to hypoxia. The weight gain in the compression chamber was particularly low in the early exposed group (HP). The mean weight of the small rats was lowered most in group HT (p 0.001). In conclusion, exposure to hypoxia is particularly damaging if it occurs in the second half of pregnancy but if hypoxia occurs only in the first half of pregnancy there are disturbances. Exposure to hypoxia goes up mainly as an increase in neonatal mortality with low birth weights.(ABSTRACT TRUNCATED AT 250 WORDS)
Guyard
B
B
Laboratoire de Physiologie, UFR de Médecine, Bobigny.
Richalet
J P
JP
Kacimi
R
R
Berrou
J P
JP
Madelenat
P
P
D000531:Altitude; D000818:Animals; D001274:Atmospheric Pressure; D001724:Birth Weight; D005247:Feeding Behavior; D005260:Female; D005313:Fetal Death; D005865:Gestational Age; D000860:Hypoxia / Q000150:complications / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain
D010100:Oxygen
Altitude et grossesse. A propos d'un travail expérimental sur la rate gestante.