Plasma osmolality and electrolytes during the post partum months in Ghanaian women.

Plasma osmolality and electrolytes levels were determined in lactating women during the period of 7th week to the 18th month post partum and compared with the levels seen in a control group of non-pregnant non-lactating women of the same age group (18-30 years). On the whole, plasma sodium, chloride and osmolality levels in the lactating women were found to be slightly but significantly elevated, while the plasma potassium levels were lowered. We suggest that these are due to the effects of increased ACTH secretion that occurs during lactation.