Physiological and Psychological Changes in the Third Trimester
Pregnant woman in the third trimester
The third trimester of pregnancy, typically spanning weeks 28 to 40, is a remarkable period of transformation as the body prepares for childbirth. This phase is characterised by significant physiological and psychological changes that are essential for the baby’s development and the mother’s readiness for labour. Understanding these changes can help expectant mothers navigate the challenges and celebrate the incredible process that their body is going through.
Physiological Changes
1. Hormonal Shifts
The third trimester sees an increase in key hormones, including:
Relaxin: This hormone softens ligaments and joints, particularly in the pelvis, to prepare for delivery. However, it can also lead to joint pain or instability. If you already suffer from issues with your joints it is worthwhile investing a good pregnancy support band for the final trimester. It could also be beneficial to speak to your healthcare provider about alternative therapies like reflexology, osteopathy or acupuncture.
Oxytocin: Known as the “love hormone”, oxytocin prepares the uterus for contractions and promotes bonding after birth.
Progesterone and Oestrogen: These hormones reach peak levels, supporting fetal development and contributing to physical changes such as breast enlargement and milk production.
2. Physical Adjustments
Weight Gain: Most women gain about 5-9 kilograms during the third trimester, accounting for the baby, amniotic fluid, and increased blood volume.
Back Pain and Pelvic Pressure: As the uterus expands, it places pressure on the lower back and pelvis, often causing discomfort. Investing in a good pregnancy support band and pregnancy pillow can be key if you are experiencing any of these systems. If pain is becoming too much speak to your healthcare provider about pain management and alternative therapies like: Acupuncture, osteopathy, pregnancy massage and reflexology are all possible
Shortness of Breath: The growing uterus can compress the diaphragm, leading to a sensation of breathlessness. This is a great opportunity to practice breath work and focus on strengthening those lungs for labour!
Swelling (Oedema): Many women experience swelling in their feet, ankles, and hands due to fluid retention and increased pressure on blood vessels. If you experience any of these symptoms it is important to flag them to your healthcare provider.
Braxton Hicks Contractions: Often called “practice contractions”, these are irregular and usually painless contractions that help prepare the uterus for labour. They will not develop a pattern or progress.
3. Fetal Development
By the third trimester, the baby’s organs are nearly fully developed. The brain, lungs, and fat stores continue to mature in preparation for life outside the womb.
Myth: fetal movements should not decrease as you progress in your pregnancy. It is a common myth that due to limited space, movements should change or decrease. If you experience a drop in fetal movements, call your maternity triage immediately.
Psychological Changes
1. Heightened Emotions
Nesting Instinct: Many women feel an overwhelming urge to clean, organise, or prepare the home for the baby’s arrival. This behaviour is thought to be influenced by hormonal changes.
Anxiety: Concerns about labour, delivery, and parenting are common. Hormonal fluctuations and the anticipation of a life-changing event can heighten these feelings. This is great opportunity to practice communication about your feelings with your support network. Pregnancy circles and antenatal support groups/classes are a great way to share your concerns and feelings.
Mood Swings: The combination of physical discomfort and hormonal changes can lead to irritability or emotional sensitivity.
2. Cognitive Changes
Pregnancy Brain: Some women report forgetfulness or difficulty concentrating. While anecdotal, this phenomenon may result from disrupted sleep, hormonal shifts, and the mental load of preparing for motherhood.
3. Social and Relational Changes
Increased Dependency: The physical challenges of the third trimester may lead some women to rely more on their partners or support networks.
Bonding with Baby: As birth approaches, many women report stronger emotional connections to their unborn child, often facilitated by feeling movements and preparing for birth.
Tips for Managing the Third Trimester
Stay Active: Gentle exercises, such as prenatal yoga or walking, can alleviate back pain, improve circulation, and boost mood.
Prioritise Rest: Invest in comfortable pillows and practice relaxation techniques to improve sleep quality.
Hydration and Nutrition: Maintain a balanced diet rich in protein, iron, and calcium. Drink plenty of water to reduce swelling and support overall health.
Educate Yourself: Attend antenatal classes and learn about labour and breastfeeding to feel more prepared.
Seek Support: Share concerns with your partner, friends, or healthcare provider. Emotional and practical support can ease anxiety.
Conclusion
The third trimester is a time of profound change as both the mother and baby prepare for the journey of childbirth. By understanding the physiological and psychological changes that occur, expectant mothers can embrace this phase with confidence and care. With the right support, education, and self-care, the third trimester can be a fulfilling chapter in the incredible journey of motherhood.
