Hormones and Body Changes During Pregnancy

During pregnancy, there are a number of profound physical and emotional changes, largely driven by a complex interplay of hormones. Understanding these hormones and their functions can help you navigate your pregnancy journey more comfortably. This guide will cover the main pregnancy hormones, their roles, and tips for managing these changes.

What are the key hormone changes in pregnancy?

Several hormones play crucial roles in supporting the development of the fetus and preparing the mother's body for childbirth and lactation. These include:

• Follicle-Stimulating Hormone (FSH) - Stimulates the growth of ovarian follicles before the release of an egg.
• Luteinizing Hormone (LH)- Triggers ovulation and supports the initial stages of pregnancy.
• Human Chorionic Gonadotropin (hCG) – This hormone is produced by the placenta shortly after the embryo attaches to the uterine lining. It rises rapidly, doubling every 48 hours or so. HCG is crucial for maintaining the corpus luteum, which in turn produces progesterone during early pregnancy.
• Oestrogen – This hormone plays multiple roles, including regulating the growth of the uterus, and supports the baby until the placenta takes over.
• Progesterone – This essential hormone maintains the uterine lining for a fertilised egg to implant, and helps prevent premature labour by relaxing the uterine muscles.
• Relaxin - Helps relax the ligaments in the pelvis and soften the cervix in preparation for childbirth. Relaxin is also thought to be the cause of reflux and heartburn during pregnancy as it relaxes the stomach muscles
• Oxytocin – This is also known as the "love hormone". It stimulates uterine contractions during labour and milk ejection during breastfeeding.
• Prolactin – This is essential for milk supply as it promotes milk production in the breasts after birth. Prolactin levels start to increase during the second trimester when colostrum is being formed.

What week do hormones peak in pregnancy?

Hormone levels fluctuate throughout pregnancy, each peaking at different times:

• HCG peaks around 10 weeks, often coinciding with early pregnancy symptoms like nausea.
• Oestrogen and Progesterone gradually rise throughout pregnancy, peaking in the third trimester.
• Relaxin peaks in the first trimester and again in the last weeks of pregnancy to prepare for childbirth.

Emotional changes can begin as early as the first few weeks of pregnancy due to these hormonal fluctuations. Nausea and fatigue during early pregnancy can contribute to feelings of tearfulness, but for most people, this is just temporary.

Oestrogen

Oestrogen is a group of hormones responsible for the development of female secondary sexual characteristics and the regulation of the menstrual cycle. During pregnancy, oestrogen helps to stimulate uterine growth, enhance blood flow between the uterus and placenta. It is also thought to help the development of the baby's organs and promote the healthy function of the placenta.

Oestrogen promotes the growth and development of milk ducts in the breasts in preparation for breastfeeding. Oestrogen levels start to rise after conception and continue to increase throughout pregnancy, supporting various physiological changes needed for a healthy pregnancy and fetal development.

Progesterone

Progesterone is a hormone produced by the ovaries and the placenta during pregnancy. In early pregnancy, progesterone is essential for maintaining the uterine lining for implantation, inhibiting contractions to prevent early labour, and supporting the development of the placenta. Progesterone levels increase significantly after ovulation and continue to rise during pregnancy, peaking in the third trimester to ensure the pregnancy is maintained.

Oestrogen vs. Progesterone

Both oestrogen and progesterone levels need to be optimal as they work hand in hand to create an optimal environment for pregnancy. Many of the functions of progesterone require oestrogen to be effective. Together they help prepare the uterus for implantation, maintain the pregnancy, support fetal growth and development, prepare the body for childbirth and breastfeeding.

Top tips on navigating pregnancy hormones

Your mood may be impacted by pregnancy hormones, particularly during the first three months. One moment you could be pleased and excited, and the next you might be anxious or sad. While occasional highs and lows are normal, it's important to talk to your doctor or midwife if you are constantly feeling low. It’s important to know that if you experience any of these feelings, you are not alone.

Additionally, the physical changes brought on by pregnancy can have an impact on your emotional state. Some people who are giving birth feel confident and strong in their pregnant bodies. Some people don't like being pregnant or how it makes them feel or look. Your mood may also be affected by health issues, such as nausea, general life stresses like money worries, or difficulty sleeping. There are some things you can do to help navigate the emotional changes that may occur as a result of pregnancy hormones:

1. Healthy Diet - Balanced nutrition supports hormone regulation.
2. Exercise - Regular, moderate exercise can help manage mood swings.
3. Rest - Adequate sleep is crucial for hormonal balance.
4. Stay Hydrated - Proper hydration will help support your overall health and wellbeing.
5. Seek Support - Don’t hesitate to talk to healthcare providers about any concerns.

The hormonal changes during pregnancy can be significant and it’s no wonder so many women and birthing people experience dramatic emotional and physical changes during this time. Understanding these changes and knowing that they are a normal part of pregnancy can help you feel more at ease. Embracing the journey with knowledge and support can make the transition smoother and more manageable.