Prolactin levels in nursing mothers.
Plasma prolactin (hPRL) concentration was measured in four nursing mothers during 24 hour periods. Blood was collected via indwelling catheters and sleep and nursing periods were recorded. Elevated hRPL levels and amenorrhea were seen for as long as 13 months post partum in mothers whose infants nursed frequently. One mother, whose infant nursed less frequently, menstruated and had lower prolactin levels but continued to lactate. Plasma hPRL rose after nursing periods in nine of 18 instances at two months post partum, but in only five of 27 instances at six months post partum. Nighttime release hPRL was higher (five of six) in nursing mothers, just as in normal subjects (five of seven). Therefore it was concluded that prolactin levels in nursing mothers may remain elevated for over one year post partum if frequent nursing continues. Lactation may continue in spite of normal hPRL levels. A consistent rise in hPRL is not seen with nursing episodes occurring after two months post partum. Nursing mothers, like normal women, tend to have higher nighttime release of hPRL.
D000568:Amenorrhea / Q000209:etiology; D001942:Breast Feeding; D005260:Female; D006801:Humans; D011388:Prolactin / Q000097:blood*
D011388:Prolactin