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Week 28 of Pregnancy

Written by Amina Hatia RM
Medically reviewed by Marley Hall BA RM Diphe
February 14, 2022

And just like that, you are now in the third trimester of your pregnancy – a mere 3 months away from your due date and maybe even less (or a week or two more!) in meeting your baby.

This week you will have a routine 28-week appointment with your midwife to check your blood pressure, your urine, monitor your baby’s growth and listen to your little one’s heart rate. You’ll also have routine antenatal blood tests taken – a full blood count (FBC) and a Group & Screen (G+S) to ensure all is well with you and you’re ready for the birth of your baby.

Listening into your baby’s heart is always lovely and your midwife will discuss with you what they can hear and what it means. During routine antenatal care your midwife will first palpate (feel) your bump to work out where baby is lying, then measure it to monitor baby’s growth and then work out depending on how your baby is lying where to listen.

They will first use a tool called a Pinard – it is funnel shaped, made of wood, metal or plastic tool that is placed on your lower tummy at one end and the midwife will then place their ear on the other end to listen to your baby’s heartbeat. Then the midwife will use a handheld machine called a doppler which uses ultrasound technology to bounce sound waves off your baby and return a representation of their heartbeat.

Similar to the Pinard, the midwife will place the wand that is attached to the machine on your lower abdomen (with some gel on the tip) to listen to your baby’s heartbeat.  It’s not painful at all, though you may not like the feel of the gel on your tummy.

Your midwife / doctor is trained in using the machine and knows what to look out for, as well as differentiate between your heartbeat and your baby’s. It’s important not to use a machine on yourself at home.

How big is my baby at 28 weeks?

Now that you are in your third trimester it’s all about growth – at 28 weeks your baby is measuring close to the size of lovely leafy lettuce – about 37.5 centimetres in length from the top of their head down to their feet and weighing about 1 kilogram!

What happens in week 28 of pregnancy?

At the beginning of the third trimester lots of changes are afoot this week, starting with lots of development on your baby’s brain growth. At 28 weeks furrows and little ridges are starting to develop on your baby’s brain, changing the smooth appearance and looking a lot more like how brains do.

Similarly, this week there is an increase in the frequency of your baby’s eye movements which is associated with deep REM sleep and brain development.

Week 28 pregnancy symptoms

Rhesus disease and Anti-D 

At the start of your pregnancy your midwife will have taken your blood to determine what your blood group is and what your rhesus status is. If you were found to be Rhesus negative, you will have been advised of this and may have been offered a further blood test at around 16 weeks in your pregnancy called ‘Fetal Rhesus D screening’ which looks at your baby’s DNA carried in your plasma cells to predict the rhesus status of your baby. If you weren’t offered the test at 16 weeks, it will be assumed your baby is positive as that is the more common RH status.

If your baby is Rhesus positive there is a mismatch between your rhesus status and your baby’s. This can be an issue as during pregnancy and birth there are times when your baby’s blood may mix with yours such as a small bleed from the placenta or if you have had a fall/knock to your bump. Similarly, your blood and your baby’s will also come into contact during birth.

If you are RH negative and your baby positive, your body will treat your baby’s blood as an invader and produce antibodies to destroy blood cells from your baby. This can be an issue in your next pregnancy if you have another RhD-positive baby, as the antibodies will attack the RhD-positive baby’s blood cells.

For this reason, you will be offered an injection called Anti-D that is injected into a muscle in your arm when you are 28 weeks. This injection helps to prevent Rhesus disease in the new-born occurring. If you experience a knock to your bump or any bleeding in pregnancy, you will be offered additional Anti-D, even if you have had your 28-week dose.

Week 28 pregnancy tips

  • Check you need and have an appointment arranged for Anti-D this week – it may be part of your routine 28-week antenatal check or may need to be arranged separately.
  • As you enter your third trimester, do you know how and when to contact your maternity unit if you are worried or experiencing symptoms you aren’t sure of. Your maternity notes should have the number to call 24/7 if you are ever worried – often on the front of your notes.
  • What are your thoughts on where to have a baby – have you explored all the options available, or just not sure about what any of them mean? We cover birth choices in our Journey to Motherhood and go into detail what each option for where to give birth means – our midwives are all experienced in home, birth centre and hospital birth and will give their honest advice with you.