Pesky Hormones Responsible for Mood Swings

*Embarking on the incredible journey of pregnancy is a profound and transformative experience, marked by a series of physical and emotional changes. Amongst these are the first-trimester ‘mood swings’. You might often find yourself feeling tearful and easily irritated without an obvious reason. Often the culprit for this emotional rollercoaster is your hormones, as they fluctuate to support you and your baby.*

## Mood Swings

The first two hormones to step into action once you a pregnant are progesterone and oestrogen. These hormones also fluctuate, to a lesser degree, during your menstrual cycle, and increases in progesterone between days 15-28 of menstruation is associated with those mood swings also.

### Progesterone

Progesterone is expected to remain heightened during pregnancy, but particularly so during the first trimester. Its function is to prepare the uterus lining for the egg to implant and to act as a muscle relaxant, preventing your uterus from contracting until the onset of labour [1].

Progesterone is known to affect mood in many ways, these include its appearance within the brain and its conversion into cortisol [2].

Progesterone can pass through the blood-brain barrier easily meaning its concentration within some areas of the brain may be higher than within the bloodstream itself. These areas of the brain, notably the amygdala and hypothalamus, are associated with emotional regulation. Secondly, progesterone can be converted into cortisol leading to heightened levels of stress.

### Oestrogen

Oestrogen also plays a crucial role in mood regulation. This hormone helps regulate progesterone, whilst also playing an important role maintaining the endometrial lining vital to baby’s development [3]. Over time, oestrogen will help reduce the fluctuation of progesterone within the body, which for many women will lessen their mood swings.

Mood swings are commonly felt from week 6 to week 10 of pregnancy [4]. As the placenta starts to support the baby’s endocrine system more, these hormones can begin to decrease slightly, and your body becomes used to this new ‘normal’ level, reducing the mood swings intensity. This means that mood swings are especially true in the first trimester. However, they can be experienced throughout the pregnancy due to hormonal reasons, as well as the day-to-day preparation for life with a baby and the transition.

## Pregnancy Sickness

The increased production of progesterone and oestrogen which prevented you from coming on your period may have triggered you to take a pregnancy test. However, the hormone detected within the test is human chorionic gonadotropin (Hcg) [5].

Around week 5, you may be beginning to feel nauseas, and between weeks 8 and 11 you may be experiencing the dreaded ‘pregnancy sickness’ [6]. Hcg is the hormonal culprit here, however little is understood as to how this hormone can increase nausea, instead relying on evidence that pinpoints heightened nausea with heightened Hcg [7]. This nausea and vomiting can increase anxiety, which can contribute towards fluctuating mood swings [8]

Pregnancy sickness affects each woman differently. Some don’t experience much of it at all, whilst others may have bouts of nausea and sickness within each trimester. If you are worried about nausea and sickness it is always best to book an appointment with your doctor, who may be able to prescribe you anti-sickness medication.

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> Mood swings impact each woman differently and are most likely caused by the fluctuation in your hormones as they help prepare your body for pregnancy. Although an entirely normal part of your pregnancy journey, they can be upsetting and difficult to understand. Creating an accepting culture from the people around you by developing an awareness of the hormonal factors can be an important step in understanding and regulating your emotions.

It can be difficult for both you and your support system, as everyone attempts to navigate the emotional minefield. Recognizing which hormones are causing these mood swings can help you, and the people supporting you, through the early stages of your pregnancy journey, creating a positive and understanding atmosphere for you to thrive.