The COVID-19 pandemic has disrupted so many things, so why shouldn’t it disrupt a teenage girl’s menstrual periods? Here’s some of what we have been hearing from patients:

  • A 13-year-old had heavy menstrual periods every two weeks. (Too many!)

  • A 17-year-old had not had her menstrual period for six months (Too few!)

How do we know what’s “just right”? Here’s what you need to know.

When do most girls get their first menstrual period? “Menarche,” the technical term, occurs between ages 10 and 15.

What is the menstrual “cycle?” Each month, hormones from the brain stimulate hormones from the ovaries to thicken the lining of the uterus in preparation for a possible pregnancy. If no pregnancy happens, then the lining begins to break down and it flows through the vagina and is the menstrual period. The “bleeding” usually lasts about five days, and it can be shorter or longer, but more than eight days is too long. Meanwhile, the brain, the ovaries, and the uterus keep hoping for a pregnancy (never ever giving up), so the cycle keeps happening, usually monthly.

What causes the menstrual cycle to be “irregular”? For the first two to three years after menarche, periods may not be monthly, and this is perfectly normal. With age, the timing of the menstrual cycles tends to regulate, and each menstrual cycle starts to look the same.

But the cycle is very sensitive; both emotional and physical changes, such as those that we have seen during the pandemic, can upset it. Here are some examples:

Increased stress: Since the start of the pandemic, mental health emergencies among children have increased. Between March and October 2020, emergency department (ED) visits for children with mental health emergencies increased 24% for children aged 5-11 and 31% for children aged 12-17. There was also a more than 50% increase in ED visits for suicide attempts among girls aged 12-17 from 2019 to early 2021.

Increased obesity: Online school, increased screen time, no after-school activities, and changes to diet have contributed to weight gain for many children during the pandemic. According to a report from the Centers for Disease Control and Prevention (CDC), among a group of more than 400,000 people aged 2-19, the rate of body mass index (BMI) increase doubled during the pandemic. Those who were overweight pre-pandemic and younger school-aged children experienced the largest increases.

Increased eating disorders: A survey in the International Journal of Eating Disorders in July 2020 found that nearly two-thirds of people with anorexia and nearly a third with binge-eating disorder reported a worsening of symptoms during the pandemic.

Increased infections: As of Nov. 11, more than 6.6 million children have tested positive for COVID-19 since the pandemic began.

What about the COVID-19 vaccine? Although some media reports have suggested a connection, there is currently not enough evidence to conclude that changes in menstrual cycles can be linked to COVID-19 vaccination, especially given how common menstrual disorders are in general. The National Institutes of Health (NIH) has recently distributed more than $1 million in grants to investigate this further.

What do the experts say? The North American Society for Pediatric and Gynecology (NASPAG) recommends COVID-19 vaccinations for all eligible children, adolescents, and young adults. They note that irregular menstrual cycles in adolescents are common. Even if the vaccine affects menstrual cycles, it is likely short-term and self-limited. Also, NASPAG states that there are no scientific data that link COVID-19 vaccines and infertility.

Menstrual periods are sometimes a “hush-hush” topic for girls. During the pandemic, health classes may have been suboptimal or skipped entirely, making it even less likely to be a topic that they talk about. In addition, they may have missed their checkups with their health care providers who would have asked them questions about their menstrual periods.

Take-home points:

  • Parents should start the conversation with their teenage daughters about their menstrual periods – what is in the range of normal, and what may cause irregular cycles.

  • Girls should be encouraged to track their menstrual cycles to become familiar with what their “just right” is. There’s an app for this.

  • Schedule your daughter’s checkup so that she can speak with her health care provider about her menstrual period.

Rima Himelstein is an adolescent medicine specialist and Sarah Mumanachit is a third-year pediatric resident at Nemours Children’s Hospital, Delaware.