BODY TEMPERATURE AND OVULATION
Medical textbooks say that a woman’s temperature goes up when her ovary releases an egg, and many women who prefer natural methods of birth control use temperature readings as a guide to sexual activity. But a study at the Masters and Johnson Institute in St. Louis has found that the relationship between temperature and ovulation is not nearly so precise as has been thought.
The study compared temperature readings and hormonal levels in ninety-eight women. In a majority of the women, increases in body temperature and peak levels of the hormone associated with ovulation did not coincide. In addition, one of every five women in the study did not have the two-phase temperature pattern—low in the first half of the menstrual cycle, higher during and after ovulation—that is supposed to be the rule.
“Even for women who did show the two-phase pattern, the time of the shift in temperature was not as closely associated with the time of ovulation as was previously believed,” says endocrinologist Joan E. Bauman, who reported on the study in the journal Fertility and Sterility.
“Unfortunately, there’s just no good way, aside from bringing a woman into the laboratory, to pinpoint the day of ovulation.”
VITAMIN B-6 NEEDS DURING NURSING
Women who breast-feed may not be receiving enough vitamin B-6 to meet the needs of their infants, report Purdue University researchers Avanelle Kirksey and Lynn Styslinger. Vitamin B-6 plays an important role in the development of a baby’s central nervous system; a deficiency can cause such problems as extreme irritability and convulsions.
In tests of milk from twenty-four lactating women, Kerseys and Styslinger found that even women who were taking extra vitamin B-6 generally had low levels of it. To ensure an adequate B-6 intake for their babies, most mothers in the study needed to take 20 milligrams a day of the vitamin—eight times the current recommended daily amount.
Women who have used oral contraceptives tend to have very low vitamin 8-6 levels, Kirksey notes. There’s no danger in taking high levels of 8-6, she says. “It has very low toxicity.”