Menstrual Disorders And Pregnancy Complications

The menstrual cycle is the monthly fertility cycle in people assigned female at birth (AFAB), and is controlled by chemical messengers in the body known as hormones. Menstrual disorders are difficulties with this cycle that can have a significant impact on quality of life.  Some of the conditions that cause menstrual disorders are associated with a higher chance of pregnancy complications, posing a potential risk to the birthing parent and their baby in some way.  Here, we will look at menstrual disorders and pregnancy problems in more detail.

Menstrual disorders

Some people have regular menstrual cycles and little to no issues every month.  Many, however, experience problems leading up to or during menstruation (their periods).  Before we look at the different types of menstrual disorders, it’s helpful to first look at what the menstrual cycle is.

The menstrual cycle

The menstrual cycle is the monthly fertility cycle in people assigned female at birth (AFAB), and is controlled by chemical messengers in the body known as hormones.  It begins with a 5-8 day period, or the bleeding phase, and lasts on average 28 days.  These durations vary between individuals, and what is “usual” for one may not be “usual” for another.

What types of menstrual disorders are there?

Menstrual disorders can be caused by a variety of conditions and can affect the menstrual cycle in a range of ways. These include premenstrual problems, abnormal variations in the amount of blood lost, differences in the timing of the cycles and painful periods.1

Common types of menstrual disorders

  • Dysmenorrhoea: These are painful periods with features like cramping in your abdomen (tummy).
  • Premenstrual Syndrome: A variety of emotional or physical symptoms occurring before your period.
  • Amenorrhoea: The absence of periods – not having them for a certain amount of time.
  • Menorrhagia/ Heavy menstrual bleeding (HMB): Heavy periods with lots of bleeding.
  • Irregular Periods: If a single gap between periods is less than 21 days or more than 35 days. This is also an umbrella term that covers irregular variations between cycles.

Complications of pregnancy

Although most pregnancies are considered low-risk, some people experience health problems during this time.  This can be due to conditions that were present before becoming pregnant or due to conditions that developed during the pregnancy.

What are some common pregnancy complications?

  • High blood pressure (Hypertension): This is when the arteries, which are the vessels taking blood from the heart around the body, become narrowed, and the force of the blood pushing against them increases.  During pregnancy, if this is severe or not well controlled, it can cause harm to the parent or baby. As your body provides for the developing child, there can be additional strain on your heart and kidneys, leading to disease.2
  • Pre-eclampsia: Usually developing after 20 weeks pregnant, this is a serious disorder affecting different organs that is characterised by high blood pressure and protein in your urine.  It can lead to eclampsia, which affects the brain and causes seizures. Delivering the baby early is one treatment option for pre-eclampsia, as well as medicine to reduce blood pressure.
  • Gestational Diabetes: When someone develops diabetes during pregnancy, it is called gestational diabetes. In diabetes, there is a problem managing the amount of glucose (sugar) in your blood.  Consistently high blood sugar levels can be bad for your health and put your baby at risk of being born larger than normal, increasing the risk of difficult labour and the need for a caesarean section.
  • Miscarriage: Losing the pregnancy before the 20th week is called a miscarriage.  Spotting, bleeding and cramping are signs that a miscarriage may be underway, although not all vaginal bleeding is a guarantee of it occurring. This can be psychologically traumatic for the parents, and you may be offered support in the form of charities, websites and health services.
  • Premature Labour: Going into labour before the 37th week can be caused by many factors, with infections and inflammation often associated.  Delivering a baby at an earlier developmental stage means a greater chance of them having health problems that last into adulthood. 
  • Depression and Anxiety: A common mental health condition, depression is thought to affect around 10-20% of American women during the pregnancy period and sometime after.3  It is linked with other complications such as a low birth weight, preterm birth, and an increased likelihood of the child having impaired social, behavioural and cognitive skills. Although the “baby blues” are very common, perinatal depression is classified as symptoms lasting at least 14 days and impairing your quality of life.3

What is the link between menstrual disorders and pregnancy complications?

With many different types of menstrual disorders, it’s best to look out for any potential problems that may arise when trying to conceive and during and after the pregnancy.  This section will present the evidence linking conditions that cause menstrual disorders with higher risks of pregnancy complications.

Dysmenorrhoea and pregnancy complications

Dysmenorrhoea can be classed as primary or secondary, depending on whether there is the presence of a problem in the pelvis. One study in Japan investigated a large group of people with different types of dysmenorrhoea for complications during pregnancy and found an increased likelihood of preterm birth before 37 weeks for those suffering from “severe” dysmenorrhoea but no difference in preterm birth before 34 weeks.4

Endometriosis and adenomyosis (growth of uterine lining outside of the uterus) are both common causes of dysmenorrhea, irregular periods and HMB.  They have been associated with problems with fertility, preterm birth, pre-eclampsia, miscarriage and placental pathology (where there’s an issue with the placenta), among others.  Endometriosis is also a risk factor for an ectopic pregnancy, which is a non-viable pregnancy caused by a fertilised egg implanting itself somewhere other than the uterus.5,6

Premenstrual syndrome and pregnancy complications

Premenstrual syndrome has been associated with both antenatal (before birth)7 and postnatal (after birth) depression.8

Amenorrhoea and pregnancy complications

Many conditions can cause amenorrhoea, including pregnancy itself.  Amenorrhoea is classified as either primary or secondary. Primary amenorrhoea is when you haven’t had a period by age 15, whereas secondary amenorrhoea is when you have had periods but you haven’t had one for at least 3 months.  

The two most common causes of secondary amenorrhoea are polycystic ovary syndrome (PCOS) and functional hypothalamic amenorrhoea (FHA).9 However, there are also a variety of other conditions that can lead to it, including type 1 diabetes and issues with the thyroid gland.

Since this is such a diverse group of problems, the pregnancy complications associated with them can vary.

Most PCOS patients experience ovulation problems, which leads to subfertility (failure to conceive after at least a year of unprotected sex) or infertility. Once pregnant, those with PCOS are at a higher risk of gestational diabetes, having a small gestational age infant and a preterm delivery.10

Given that most cases of FHA are caused by an imbalance between energy intake and energy usage in the body, the risks usually come from the mother being underweight. This should ideally be addressed before conceiving as there is a higher risk of pregnancy loss, preterm labour, low birth weight and the need for a caesarean section.11 Stress is also a contributing factor.

Pregnancy and HMB

This type of abnormal uterine bleeding is when there is heavy or prolonged menstrual bleeding.  It can be a struggle to live with, interfering often with daily life, and may be caused by a few things.

The most common causes are:

  • Hormonal imbalances
  • Not releasing an egg (ovulating) every month
  • Having things in the uterus that shouldn’t be there, like polyps and fibroids
  • Having excessive bleeding in the body, whether through disease or medication

Like amenorrhoea, because of the varied nature of conditions that can cause HMB, there is a range of pregnancy complications that are linked to each condition.

Uterine abnormalities, such as polyps and fibroids, are associated with subfertility and recurrent pregnancy loss.12,13,14 Fibroids can also undergo a process called “degeneration” where they stop receiving an adequate blood supply, causing pain. 

HMB can also be indicative of problems with the amount of platelets (things that help clot the blood), which can lead to a more risky delivery and epidural administration.15

Ectopic pregnancies, as well as miscarriages, can cause HMB.

PCOS is another possible cause of HMB, as are endometriosis and adenomyosis.

Do irregular periods lead to pregnancy complications?

Again, this depends on underlying conditions.  People with PCOS, thyroid issues, endometriosis, fibroids or adenomyosis may experience irregular periods and have the complications mentioned above. Another potential cause is pelvic inflammatory disease (PID), which can affect fertility and make ectopic pregnancies more likely.

Addressing menstrual disorders during pregnancy and managing complications

Since menstrual disorders can be present because of an underlying condition, talking with a healthcare professional before trying to conceive would give you a better chance of managing your condition throughout your pregnancy, particularly as some treatments may be harmful to the baby.  It would be worthwhile to find out how your condition can affect pregnancy, and vice versa, and whether it is a “high-risk” pregnancy that requires closer monitoring.

Most pregnancies progress without complications, and often, whatever is causing the menstrual disorder only slightly increases the risk. If you do experience a complication, it is important to inform a healthcare professional.


We have explored the relationship between menstrual disorders and pregnancy complications and seen how different conditions can be associated with more than one disorder. Understanding these connections means you can be informed before and during your pregnancy and aim to have as healthy a pregnancy as possible.


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  4. Murata T, Endo Y, Fukuda T, Kyozuka H, Yasuda S, Yamaguchi A, et al. Association of preconception dysmenorrhea with obstetric complications: the Japan Environment and Children’s Study. BMC Pregnancy Childbirth. 2022 Feb 15;22(1):125.
  5. Breintoft K, Pinnerup R, Henriksen TB, Rytter D, Uldbjerg N, Forman A, et al. Endometriosis and risk of adverse pregnancy outcome: a systematic review and meta-analysis. J Clin Med. 2021 Feb 9;10(4):667.
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  7. Roomruangwong C, Kanchanatawan B, Sirivichayakul S, Maes M. Antenatal depression and hematocrit levels as predictors of postpartum depression and anxiety symptoms. Psychiatry Res. 2016 Apr 30;238:211–7.
  8. Saleh ES, El-Bahei W, Del El-Hadidy MA, Zayed A. Predictors of postpartum depression in a sample of Egyptian women. Neuropsychiatr Dis Treat. 2013;9:15–24.
  9. Phylactou M, Clarke SA, Patel B, Baggaley C, Jayasena CN, Kelsey TW, et al. Clinical and biochemical discriminants between functional hypothalamic amenorrhoea (Fha) and polycystic ovary syndrome (Pcos). Clin Endocrinol (Oxf). 2021 Aug;95(2):239–52.
  10. de Wilde MA, Lamain-de Ruiter M, Veltman-Verhulst SM, Kwee A, Laven JS, Lambalk CB, et al. Increased rates of complications in singleton pregnancies of women previously diagnosed with polycystic ovary syndrome predominantly in the hyperandrogenic phenotype. Fertil Steril. 2017 Aug;108(2):333–40.
  11. Roberts RE, Farahani L, Webber L, Jayasena C. Current understanding of hypothalamic amenorrhoea. Ther Adv Endocrinol Metab. 2020;11:2042018820945854.
  12. Carbonnel M, Pirtea P, de Ziegler D, Ayoubi JM. Uterine factors in recurrent pregnancy losses. Fertil Steril. 2021 Mar;115(3):538–45.
  13. Al Chami A, Saridogan E. Endometrial polyps and subfertility. J Obstet Gynaecol India. 2017 Feb;67(1):9–14.
  14. Pier BD, Bates GW. Potential causes of subfertility in patients with intramural fibroids. Fertil Res Pract. 2015;1:12.
  15. Pishko AM, Marshall AL. Thrombocytopenia in pregnancy. Hematology Am Soc Hematol Educ Program. 2022 Dec 9;2022(1):303–11.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Christopher Burke

MBBS, GKT School of Medical Education, King's College London

Chris is a tutor who holds a degree in medicine from King's College London. He enjoys writing informative yet easy to read articles relating to health and disease with the aim of educating people about various conditions. During his time at university, he continually worked on his writing and presentation skills, and was awarded the highest mark of his cohort for a literature review. He has helped many students from primary school to university level achieve their goals and is particularly interested in immunology research. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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