At your first appointment with your midwife, the booking appointment, your midwife will identify if you have risk factors for having a small baby, such as smoking, current or previous problems with raised blood pressure or if you have had a previous small baby. If this is the case serial growth ultrasound scans will be offered to you during your pregnancy to measure the growth of your baby.

If your pregnancy is assessed to be low-chance for growing a small baby your midwife will measure your abdomen at every antenatal visit from 28 weeks of pregnancy. This measurement will be plotted on your customised growth chart on BadgerNet. Your customised growth chart is specific for your height, weight and ethnicity to make this assessment more accurate. If, when plotting the measurement on this chart your baby appears smaller than expected, you will be referred for an ultrasound scan.

Measuring your abdomen may not be appropriate if you have a higher BMI or if you have known fibroids in the uterus. If this is the case, we will offer you growth scans to measure the size of your baby.
 

At your ultrasound scan appointment, your baby will have measurements taken of its head, abdomen, and femur (thigh bone). From these measurements, the baby’s weight will be estimated. This weight will be compared against your gestation (how many weeks pregnant you are) on your customised growth chart. You may also have measurements taken of the blood flow (Doppler) in your baby’s umbilical cord, brain and sometimes the liver. You may also have the blood flow in your vessels that supply your womb with blood (uterine arteries) measured. 

The accuracy of the growth scan can depend on your gestation and can vary by up to 20% at the end of pregnancy. 

When your baby is born a birth weight centile will be generated. As a Trust we audit unexpected variance in birth weight centiles versus estimated fetal weight and use this information to improve training and feedback to the sonography team.
 

A baby that is small for gestational age (SGA) measures in the lowest 10% of average ultrasound scans, below the bottom black line (10th centile) on the growth chart. 9/10 babies would measure larger at the same point in pregnancy. Most of these babies are healthy during pregnancy and birth. They usually continue to put on a good amount of weight throughout the pregnancy and have no problems with the blood flow measurements on the scans.

In some cases it could be that your baby is not growing as well as they should - this is called fetal growth restriction (FGR). This is often due to the placenta not working as well as it should to support your baby’s growth. These babies are often below the 3rd centile (bottom grey line) and/or have problems with their blood flow measurements. In a small number of cases genetic problems in the baby or infections can cause Fetal Growth Restriction (FGR). 

If your baby is small for gestational age (SGA) then you will be invited to have an ultrasound scan every 2-3 weeks to monitor your baby’s growth, the amount of fluid around them (amniotic fluid volume) and blood flow.

If your baby has Fetal Growth Restriction (FGR), you will be invited to have more frequent ultrasound scans. After each scan, we will explain the findings and discuss when we need to assess your baby again.

In addition to monitoring your baby’s growth and blood flow we sometimes also do a test called a computerised cardiotocography (cCTG). This helps us assess the baby’s wellbeing in more detail.

It is also important for you to keep seeing your midwife regularly so they can regularly check your blood pressure and test your urine. 

We want to reassure you that in most cases there is nothing you have done or could have done differently to have changed the situation. It is not because you aren’t eating and drinking enough. We advise all pregnant women to have a healthy, balanced diet and stay active.

Smoking can cause problems with the placenta and can cause babies to be small. Stopping smoking can be the most positive thing you can do to help your baby be healthier during pregnancy and after birth. We understand that it can be incredibly difficult, but we can support you to stop, just speak to one of the doctors or midwives.

We will ask you to pay close attention to your baby’s movements, this is very important. If your baby’s movements4 are less than normal (in strength or frequency) or their usual pattern changes (e.g. moving at night) we want you to come to the hospital to get checked over. Please call Maternity Triage on: 01923 217 343 and they will invite you in. Please don’t leave it until the next day, it is important you come and get checked out when you are concerned. 
 

How your baby is after birth is affected by how early they are born, how small they are and whether there are any other complications.

The neonatal team will decide whether your baby needs to be admitted to the neonatal unit.

If your baby does need admission, you will be able to be with them as much as you want. Your baby will get the best possible care and support.

It isn’t possible to say before birth what exactly your baby will need and how long your baby will need to stay in the neonatal unit, this is different for each baby. The team will assess how they are coping and will regularly discuss their progress with you and plan when they are ready to go home.

Generally, babies born at later gestations tend to need less specialist care and need to be kept in hospital for shorter amounts of time. SGA (Small for gestational age) babies also tend to need less care than FGR (fetal growth restriction) babies. However, we will not send a baby home unless the team responsible for both you and your baby’s care feel it is safe to do so. Being born SGA can make it harder for your baby to feed well, maintain a normal body temperature and blood sugar levels.

Most SGA healthy babies do very well but may need a little bit of extra care initially. The midwife looking after your baby will ensure that your baby gets the best monitoring after birth. 

Having an SGA baby may increase your chances of having another SGA baby in the future. Overall, the chance of a future SGA baby is probably about one in three, and if it does occur, it tends to follow a similar pattern.

In the next pregnancy after a baby with SGA you will be closely monitored and offered additional scans. If your baby was diagnosed with FGR you will be offered aspirin in future pregnancies to reduce the chance of this happening again. A healthy lifestyle1, optimising your body weight for height and stopping smoking2 may reduce this risk even further.

Please contact your community midwife if you have any questions or concerns.