Studying menstruation as a window to pregnancy & reproductive health

A group of Hudson Institute and Monash University researchers is among the few in the world studying how menstruation – when it starts, its frequency and reliability, and whether it is painful, heavy or light – affects a woman’s likelihood of developing complications in pregnancy. 

It’s a rare venture into the potential link between a woman’s periods and her ongoing reproductive health.

Associate Professor Miranda Davies-Tuck from the Ritchie Centre, says: “There’s been a real blind spot when it comes to menstruation. When it comes to pregnancy preparation or care, virtually the only thing you’re asked is when your last period was; we think there’s way more information in your menstruation history than that.”

Links between menstruation & pregnancy outcomes

Together with PhD student, Kirsten Tindal, and Professors Beverley Vollenhoven and Caroline Gargett, A/Prof Davies-Tuck is currently running the Your Period Your Pregnancy study, investigating the association between menstruation and pregnancy outcomes in Australia, including stillbirth, preterm birth, preeclampsia and fetal growth restriction – with the aim of identifying menstrual characteristics which could act as a pregnancy risk assessment tool, and also provide more information about why these complications occur. 

“For example, we know that globally girls are starting menstruation younger and younger with around 12 per cent of Australian girls getting their period between the ages of 8 and 11,” she said. “Early onset of menstruation has been linked to developing preeclampsia, yet this is not part of current screening tools for preeclampsia risk prediction and subsequent aspirin treatment.”

Most stillbirths, and approximately two-thirds of preterm births, occur in the absence of evident risk factors. “Placental dysfunction is a major contributor to stillbirth, particularly preterm stillbirth and studying the endometrial environment may shed light on factors that influence placental development and the trajectory of a pregnancy,” she said. 

“Menstrual symptoms such as abnormal uterine bleeding can indicate undiagnosed endometrial disorders, which are associated with infertility and adverse pregnancy outcomes. However, no one has looked at whether heavy or light bleeding, cycle length, spotting or intermenstrual bleeding is associated with pregnancy outcomes in the absence of a diagnosed endometrial pathology.

Each of these symptoms, however, provides information on endometrial response to hormones, levels of inflammation, thickness and blood clotting pathways.”

Menstruation study recruiting pregnant Victorians

The study has already recruited around 800 pregnant Victorian women, with the aim to recruit 300 more. The women are aged between 18 and 45 and are in early pregnancy when they join the study, and without any diagnosed endometrial issue like endometriosis.

They complete a menstrual history survey to capture menstrual cycle length, regularity, level of pain, heaviness of flow and other menstrual symptoms in the three months before becoming pregnant. This information is then linked with their pregnancy and birth outcome information, where patterns or combinations of symptoms will be identified that predict different pregnancy outcomes.

Participants will also be invited to complete an optional fetal movements survey at 28–32 and 36+ weeks’ gestation, and consent for placental collection at the time of birth will be sought.

Connections between menstrual health and stillbirth?

In another study, the Endometrial Origins of Stillbirth (EOS) study, Associate Professor Davies-Tuck is asking Victorian women who have experienced a pregnancy loss or other adverse pregnancy outcome (preterm birth, preeclampsia or fetal growth restriction) to donate their menstrual fluid.

The study is investigating whether we can identify differences in menstrual fluid that are associated with adverse pregnancy outcomes, to uncover new mechanisms and biomarkers to improve pregnancy planning and care. 

“My hope with this work is that we will see the potential of menstruation and menstrual fluid realised and added to the clinician’s toolkit alongside other samples or clinical history taking,” A/Prof Davies-Tuck said.

If you are interested in helping shape the use of menstrual fluid research | https://hudson.org.au/cycles-for-science-study/