Week 20

During pregnancy, higher levels of oestrogen cause hair to grow longer and thicker. This is because increased levels of oestrogen lengthen the hair growth cycle.² Amazingly, both environmental and biological chemicals are absorbed into the hair during growth, and so scientists have found that hair samples can help identify biological markers for different pregnancy disorders. In fact, certain key biomarkers found in hair samples taken specifically in the second trimester were associated with women who delivered smaller-than-gestational age babies!³

• Headaches
• Heartburn and indigestion
• Dizziness
• Leg cramps
• Oedema (swelling, specifically hands or ankles)
• Bleeding gums
• Pelvic girdle pain and back ache
• Foetal movement

Head to rump (buttocks), your baby should now measure approximately 16.5 cm and weigh around 280 g.¹

Week 20 is also a significant week for your baby’s hair growth too. Hair follicles start to mature from the surface of the skin and allowing hair to form. Sweat glands are also developing and maturing, which will also help support temperature regulation.⁴

• Consistently taking folic acid is recommended,⁵ or if you haven’t already, consider taking a prenatal supplement that has the recommended amounts of vitamin A and D, iron and calcium,⁶ which will also help support your oral health⁷
• Book your routine dental check up to help support your oral health during pregnancy⁷
• Staying active and keeping a healthy weight can help support overall health⁸
• Try to avoid alcohol consumption and smoking – both are known as risk factors for miscarriage^9,10
• 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 tea¹¹
• Limit caffeine consumption to no more than 200 mg per day¹²  
  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
• You should be expecting your 20-week appointment with your healthcare provider¹³

Around 20 weeks, you should have another ultrasound scan. This appointment is to assess foetal growth, heart function, and movement. They may also be able to distinguish the gender, if you want to know.

During this period, you may also be offered genetic testing to look for genetic conditions, such as spina bifida and Down’s syndrome. You can discuss this testing with your healthcare provider.

Your antenatal appointment around 20 weeks should also include blood tests. These tests are important to check iron levels and check for gestational diabetes. They will also confirm your rhesus status, which is whether you carry rhesus antibodies on your blood cells. If you are rhesus negative, your healthcare provider will need to confirm whether any rhesus antibodies are present as these could attack the red blood cells of the baby if their blood type is rhesus positive.