In late April, reports of people who menstruate experiencing menstrual cycle changes after receiving the COVID-19 vaccine began circulating. Those reports are still being looked into, and are purely anecdotal at this point—though the response itself does seem to be temporary for those who have experienced it.
Still, the potential of menstrual cycle changes has some parents of prepubescent kids questioning whether or not the vaccine could impact their children’s hormone and cycle development.
What We Know So Far
“There is little data supporting any biologic association of the COVID vaccines to the issue of interfering with a woman’s ovulatory cycle,” Sharon Nachman, MD, Chief of the Division of Pediatric Infectious Diseases at Stony Brook Children’s Hospital, recently explained.
She said that in the clinical trials, there were reports of missed periods, but that this occurred across all vaccines and was not related to any specific one.
While these reports have continued to be submitted through the Vaccine Adverse Event Reporting System (VAERS), she said, “At this point over 80 million doses have been administered, many of these to women of child bearing ages. There has not been any drop in fertility noted with vaccine administration.”
Should Parents of Prepubescent Children Be Concerned?
Board-certified OBGYN Cynthia Flynn, MD, has more than 20 years of experience in women’s health and said definitively that the vaccine will not delay a prepubescent child’s period.
“There is no scientific mechanism of action that could cause this,” she explained.
Nachman agreed, adding that there is no data to support any link between the development of antibodies due to the Covid vaccination and a “hormonal cascade” related to ovulation.
“However, it is well known that stress does play a role in both ovulation and fertility,” Nachman said. “Stress related to Covid concerns and isolation and delays in ovulation would not be surprising.”
She explained that the way the vaccine works, providing a short DNA sequence that merely looks similar to a short DNA sequence that is part of a longer sequence, doesn’t in any way translate into the creation of specific proteins that would be required for hormone and developing cycle disruption.
“It would be akin to having 10 letters and being able to re-create a novel by a popular author,” she said. “Yes, you will be able to make up some of the words, and maybe even a sentence or two, but you will not be able to write a book using only 10 letters.”
Other Questions About Fertility
Nachman said that another thing she’s personally been asked about is whether the vaccine will decrease fertility due to ‘concerns about the placenta.’
“It is very important to understand that the placenta does not see either the vaccine or any antibodies that the mom makes after vaccination,” she explained. “It is made by the fetus and not the mom, and thus behind a ‘wall’ as it were and not subject to antibodies made by mom until the last month of pregnancy.”
Flynn stressed that the current reports are based mostly on social media, and are therefore anecdotal in nature.
“There is no reason to delay the vaccine in younger women,” she said. “Remember that about a quarter of women are going to report menstrual changes in any given month. This includes late, missing or heavy periods.”
In other words: cycle changes happen normally in the general population all the time.
“It has nothing at all to do with the vaccine,” she said.
Remembering The Real Risks
Nachman believes it’s important for parents to remember the very real and known complications of contracting Covid-19 for both children and adults.
“There are now increasing concerns about post Covid illness across the different age groups,” she said. “We have not seen any long haul Covid illness post vaccination, and several researchers are using the vaccine as part of long haul Covid treatment, with good success.”
The vaccine works. And it helps protect children and adults alike.
“At this point we continue to aim to herd immunity,” Nachman said. “Recognizing that children account for 23 percent of our population, we are at risk of making young girls second class citizens by not vaccinating them.”
She encourages parents to continuing having an ongoing dialogue with their children’s primary care provider about any concerns they may have—to include this.
“Only through that connection can questions be asked and answered, using best available data and not hearsay on social media reports.”