Cristina Carrasco Romero

Menstrual cycles were synchronised with lunar cycles until 2010, but according to research published in Science Advances, after this date, this synchrony is only found in January, when lunar gravity is at its strongest. The team analysed the menstrual records of 176 women and attributes the loss of synchrony to the increasing use of smartphones and LED night lights, which became widespread from 2010 onwards.

A team in the United States has analysed how exposure to environmental chemicals in previous generations influences the onset of the first menstruation. The researchers used data from the California Child Health and Development Study (CHDS) and analysed blood samples taken from 250 pairs from the 1960s. The results, presented at the annual meeting of the Endocrine Society in San Francisco (USA), show that although the average age of first menstruation remained stable between grandmothers and their daughters, it decreased by one year between daughters and granddaughters. Certain chemicals present in the blood of the mother and father were linked to the onset of puberty in their descendants, with stronger effects in granddaughters, according to the study, and with greater weight of male exposure.

Artemisinins, plant-based antimalarials, may serve as a treatment for polycystic ovary syndrome - which affects millions of women worldwide and can lead to infertility - according to a new study published in Science. The compounds suppressed ovarian androgen production in rodents, as well as in a small cohort of 19 human patients for 12 weeks, leading to more regular menstrual cycles without side effects. 

Research published in JAMA Network Open indicates that women with premenstrual disorders diagnosed before the age of 25 have a higher risk of all-cause mortality and death by suicide. For death by suicide, the risk increased regardless of age at diagnosis. However, in general, women with premenstrual disorders do not have an increased risk of premature death from natural and unnatural causes. The study compares over several years a group of more than 67,000 women in Sweden with a diagnosed disorder with a group of more than 338,000 women without such a diagnosis. 

The ovarian cycle is regulated by internal circadian rhythms rather than external processes, says a study published in Science Advances. Using menstrual cycle data from some 3,000 women in Europe and North America, the authors add that the influence of the lunar cycle on women's menstrual cycle is weak, but significant.

Results from a survey of more than 39,000 menstruating individuals reveal that 42% experienced heavier bleeding after SARS-CoV-2 vaccination. Among the most likely groups were pre-menopausal women, Hispanic or Latina women, those who had been pregnant, and those with conditions such as endometriosis and polycystic ovary syndrome.