Week 18

During the second trimester, your body is making increasing amounts of a hormone called relaxin. Relaxin helps to loosen the ligaments associated with the spine and pelvis to facilitate childbirth. However, consequently, around 50% of women and birthing people experience lower back and or pelvic pain (also referred to as pelvic girdle pain).²

If you are experiencing any significant back or pelvic pain, speak with your healthcare provider. They should be able to refer you to a physiotherapist that can support you using strengthening exercises to help reduce the pain.³ You can also take paracetamol if you are in pain or discomfort, but ibuprofen is not recommended during pregnancy.⁴

• Bloating and gas
• Leg cramps
• Bleeding gums
• Round ligament pain and stretch marks
• Pelvic girdle pain and back ache
• Foetal movement
• Skin changes (such as stretch marks and redder or darker palms and soles)
• Heartburn and indigestion

By now, your baby should now measure approximately 14 cm and weigh around 140 - 180 g.¹

All the structures of the ear have now formed, and your baby can hear,^1,5 and importantly, can begin to recognise your voice.¹

Week 18 of pregnancy is an important stage for your baby’s immune development. During this week specific cells called reticulum cells, start to form the main structure of the spleen. Specialised white blood cells, T and B lymphocytes then fill this structure and will continue to mature as your baby develops.⁵

• Consistently taking folic acid is recommended,⁶ or if you haven’t already, consider taking a prenatal supplement that has the recommended amounts of vitamin A and D, iron and calcium,⁷ which will also help support your oral health⁸
• Book your routine dental check up to help support your oral health during pregnancy⁸
• Staying active and keeping a healthy weight can help support overall health⁹
• Try to avoid alcohol consumption and smoking – both are known as risk factors for miscarriage^10,11
• Nourish your body with pregnancy-safe foods. Try to avoid foods high in mercury, such as mackerel and tuna, raw seafood, undercooked meat, poultry and eggs, unpasteurised foods and cheese with a mould rind such as brie, unwashed fruits and vegetables, and any type of herbal tea¹²
• Limit caffeine consumption to no more than 200 mg per day¹³ 
  As a guide: 
  1 mug of coffee contains 100 mg of caffeine  
  1 mug of tea contains 75 mg of caffeine  
  1 can of cola contains up to 40 mg of caffeine  
  1 bar of chocolate contains up to 50 mg of caffeine
• If you do not have a 20-week appointment scheduled with your healthcare provider, now is a good time to confirm¹⁴