Overview

Sheehan syndrome is defined as the shrinkage or underdevelopment of the pituitary gland following the delivery of a baby.¹ The vast majority of causes are attributed to either severe incidences of lowered blood pressure or the presence of shock following massive hemorrhage (blood loss) during delivery.¹ Such processes result in ‘necrosis’ (death) of this gland in the mother. 

The pituitary gland is a gland located at the base of the brain and is critically important for the control of numerous functions throughout the body. These include the regulation of water retention, thyroid function, lactation and functions of the ovaries or testes amongst many other functions.²

Causes and risk factors of Sheehan Syndrome

As we have briefly discussed, Sheehan Syndrome is precipitated by severe complications that can arise during labor. The two most common complications that can lead to the development of Sheehan Syndrome include major hemorrhage (blood loss) or a severe drop in blood pressure during labor. Both complications result in the same outcome for the health of the pituitary gland. For example, if large volumes of blood are lost during childbirth, or the blood pressure drops massively, then the volume of blood available for use by the pituitary gland is severely reduced. This results in the cells of the pituitary gland being starved of essential nutrients and oxygen, resulting in a process known as ‘necrosis’ (death).³

During pregnancy, the pituitary gland almost doubles in size due to its role in inducing lactation (milk production).⁴ Due to this, the blood supply to the pituitary gland also increases due to higher demands for oxygen and essential nutrients. As such, this ensures the gland is even more susceptible to the necrosis observed following hemorrhage or a severe drop in blood pressure. 

Symptoms of Sheehan Syndrome 

As the pituitary gland is responsible for controlling the vast majority of hormonal functions throughout the body, it is aptly titled the ‘master’ gland.² As such, the symptoms experienced by those with Sheehan Syndrome are specific to the hormones that are depleted through death of the pituitary gland. 

Furthermore, the progression of Sheehan Syndrome is often slow and difficult to detect, meaning the symptoms often do not present until the latter stages of the disease.¹ The following hormones and the symptoms associated with their deficiency through pituitary gland death are listed below: 

• Growth Hormone Deficiency
  • Adult Growth Hormone (AGH) has numerous functions in adulthood. Primarily, it is responsible for the production of protein, the use of fat as an energy source and the raising of blood sugar levels.⁵ As such, the following symptoms are typically associated:⁶
    • Increase in the amount of fat (particularly around the waist) 
    • Decrease in muscle mass
    • Decrease in the ability to exercise as well. Patients may notice a decrease in their strength and/or stamina
    • Patients may notice that their bones fracture more easily (especially in those that are middle-aged and above)
    • Excessive fatigue 
    • The development of anxiety and depression 
    • An overall feeling that there is a decrease in their ‘quality of life’ 
• Prolactin Deficiency
  • Prolactin is responsible for milk production through enhanced production of mammary glands (the glands responsible for this production) within the breasts.⁷ As such, in those assigned female at birth (AFAB), the following symptoms are associated:
    • In those AFAB, the predominant complaint is that of being unable to produce milk following delivery of a child.⁸ 
• Adrenocorticotropin Releasing Hormone (ACTH) Deficiency
  • ACTH is a hormone responsible for stimulating the production of cortisol (the ‘stress hormone’) from the adrenal glands (the glands located above the kidneys).⁹
  • Cortisol acts on almost every organ throughout the body, regulating important processes such as the inflammatory process, the stress response (fight or flight responses) and the production of glucose.¹⁰ As such, the following symptoms are associated with ACTH deficiency in Sheehan Syndrome:¹¹
    • Dizziness
    • Weakness
    • Fatigue 
    • Nausea and vomiting 
    • Diarrhea
    • An urge to drink water due to fluid loss
    • In AFAB, irregular or absent menstrual periods
    • Reduction in appetite
    • Muscle aches 
    • Lowered blood pressure 
• Thyroid Stimulating Hormone (TSH) deficiency
  • TSH is responsible for stimulating the thyroid gland to produce the hormone thyroxine in the body.¹² The thyroid has great influence over metabolism, skin and nail development, weight control and the regulation of our body’s temperature. As such TSH deficiency can result in the following symptoms:¹³
    • Increases sensitivity to colder temperatures 
    • Fatigue and a feeling of being ‘sluggish’ 
    • Heavier and more irregular menstrual periods 
    • Dry and sometimes flaky skin 
    • Thin, brittle and coarse hair with thin and brittle nails 
    • Weight gain 
    • Weakness 
• Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) Deficiency
  • FSH and LH are the hormones responsible for the generalized control of reproductive physiology in AFAB and those assigned male at birth (AMAB).¹⁴ 
  • In AMAB, FSH and LH are responsible for the development of the testes and their production of testosterone. In AFAB, FSH and LH are responsible for driving ovulation.¹⁴ As such, when in the deficiency, the following symptoms can be experienced:⁸
    • Lowered libido (people AFAB and people AMAB) 
    • Fatigue (people AFAB and people AMAB)
    • Infertility (people AFAB and people AMAB)
    • Erectile dysfunction (people AMAB only) 
    • Decreased facial or body hair (people AMAB) 
    • Hot flushes (people AFAB)
    • Irregular or absent periods (people AFAB)
    • Reduced pubic hair (people AFAB) 
• Antidiuretic Hormone (ADH) Deficiency
  • ADH is responsible for the reabsorption of water into the body through the kidneys.¹⁵ As such, in its absence, the following symptoms are experienced:¹⁶
    • Extreme thirst with an uncontrollable urge to drink water
    • Frequent and sometimes uncontrollable urges to urinate
• Oxytocin Deficiency
  • Whilst its main function is to facilitate childbirth, oxytocin is also responsible for the movement of milk from the breasts and the formation of romantic and paternal bonds.¹⁷ As such, when deficient, the following symptoms can occur:⁸
    • Difficulty forming a bond with the baby after its birth 
    • Difficulty interacting and a feeling of social isolation 
    • Issues with breastfeeding 

Overall, the symptoms of Sheehan Syndrome can be numerous due to the large number of hormonal functions controlled by the pituitary. 

How is Sheehan Syndrome diagnosed? 

The most common symptom patients will encounter is the inability to lactate following delivery.¹⁸ However, before making a diagnosis, the doctor may first ask you a series of questions to better get an understanding of the symptoms you may be suffering from. You may be suffering from any number of the symptoms listed above and so they may ask you to further elaborate on each of these for greater clarity. This is what is known as the ‘medical history’ of a patient. If suspicion of Sheehan Syndrome is raised, doctors may then order the following tests: 

• Blood tests
  • These blood tests will allow the doctors and other healthcare professionals to evaluate the levels of pituitary-associated hormones within the blood. This will give a clearer indication of the presence of Sheehan Syndrome
  • The levels of sodium and glucose in the blood may also be evaluated. This is because these are often lowered in cases of Sheehan Syndrome¹⁸
• Imaging
  • In some cases, doctors may also order an MRI scan to check the area of the brain where the pituitary may sit. In the instance of an absent pituitary gland, Sheehan Syndrome is likely¹⁸

How is Sheehan Syndrome treated? 

Treatment of Sheehan Syndrome focuses mostly on the replacement of the deficient hormones. This is important for not only correction of these hormones, but is also important for improving both the quality of life and mortality of patients suffering with the syndrome¹. As such, the following hormone replacements are often initiated: 

• Levothyroxine or liothyronine for the replacement of the hormones produced by the thyroid¹⁸
• Prednisolone or hydrocortisone for the replacement of cortisol¹⁸ 
• Oestrogen is used for the replacement of FSH and LH if the patient has had their uterus removed. In the presence of a uterus, estrogen and progesterone are used¹⁸
• Growth hormone replacement therapy
• Oxytocin replacement to address depleted levels of oxytocin

All treatments used in the treatment of Sheehan Syndrome are aimed at reducing the impact of the symptoms associated with these deficient hormones. In doing so, it is the aim of healthcare providers to ensure that the quality of life of patients suffering with this syndrome is greatly improved. 

Summary 

Sheehan Syndrome is a condition caused by the death of the pituitary gland following insufficient blood supply to the gland. This is caused by severe complications that can occur during labor, namely severe hemorrhage or a severe drop in blood pressure. Following death of the gland, patients can expect to experience a large decrease in the hormones produced by the pituitary. Due to this, a number of crucial functions are impacted which can result in abnormal or irregular menstrual periods, dry skin, lowered libido and mood, an increase in weight and the development of muscle aches. Sheehan Syndrome is most commonly diagnosed through a combination of a medical history and subsequent blood tests to confirm the diagnosis. In some cases, imaging tests such as MRI scans can be used to assess the presence of the gland. Treatment is aimed entirely at the replacement of the deficient hormones, thereby improving patients’ quality of life.