Saving babies’ lives - the link between fetal growth restriction and stillbirths

Posted: 09/10/2017

Historically, most stillbirths were considered ‘unexplained’. In recent years medical research has shown that the majority of stillborn babies had no abnormalities but they often weighed much less than they should.

Fetal growth restriction (FGR) occurs when a baby does not grow as well as it should during a pregnancy. This can be challenging to find before birth, so efforts are usually directed at detecting babies who are small. Research has highlighted that a baby who is small is at a much higher risk of being stillborn (up to seven times greater risk). However, this risk is at its highest if a small baby is not identified before birth; if a baby is identified as being small before birth the risk of stillbirth may be reduced by half.

Changes in practice

Midwives and doctors used to focus on identifying babies who were classed as ‘low birthweight’ (those with a birthweight of under 2.5 kg), but this has shifted in recent years to identifying those who are ‘small for gestational age’ (SGA), as this is a better predictor of babies’ outcomes. Importantly, babies who are SGA may weigh over 2.5 kg but will still face the same risk of stillbirth as if they were smaller, as they may not be growing at the rate they should. This was not previously factored into assessments, meaning that a significant number of ‘at-risk’ babies arguably did not receive the monitoring they needed during pregnancy.

Research into the cause of fetal growth restriction

The charity Tommy’s has been carrying out research into the causes of stillbirth and FGR with a view to finding a way to identify babies who are at highest risk of FGR and how stillbirth can be prevented. These projects have included discovering a link between a reduction in babies’ movements and problems with the placenta, and identifying how these problems can be detected by different tests, including more advanced ultrasound scans, MRI scans and blood tests for mothers. They are also assessing whether improving the management of mothers who feel their baby is moving less can save babies’ lives.

Professor Alexander Heazell, clinical director of the Tommy’s Research Centre, comments: “One of the most important messages to pregnant mothers is that movements matter – if a baby’s pattern of movement changes or reduces significantly then they should report this to their midwife and have their condition checked. This may save their baby’s life.”

Identifying a baby with fetal growth restriction

Due to the significantly improved chance of survival, it is important to identify babies who are at risk of FGR as early as possible during the pregnancy. Knowledge and awareness, from both professionals and parents, of the risk factors for FGR and indicators that a baby is presenting with FGR are crucial to ensuring as many babies as possible survive.

Unfortunately, there is not yet a single test in existence to identify every baby at risk of developing FGR and sadly, even with the best care, until such a test exists, some babies will be stillborn or will die shortly after birth from the complications of FGR. However, the current tools available to obstetricians and midwives to help them to identify as many growth-restricted babies as possible are:

• blood tests for Down’s syndrome screening – if a baby doesn’t have Down’s syndrome but the PAPP-A is low, this can suggest there is a risk of problems with the placenta;
• use of standardised growth charts;
• in women who are at high risk of FGR, regular ultrasound scans are recommended in late pregnancy to measure a baby’s size (usually by estimated fetal weight)
• in women who are at low risk of FGR, measurement of the fundal height by the midwife at regular antenatal appointments, allowing the midwife to identify whether the baby’s growth appears to have slowed or stopped;
• a mother’s awareness of her baby’s movements.

Guidance on FGR for expectant mothers

For a mother-to-be, the most important steps that she can take to identify whether her baby is at risk of or presenting with FGR are:

• attending all scheduled antenatal appointments;
• not smoking cigarettes or drinking alcohol during pregnancy (stopping smoking before 16 weeks of pregnancy reduces a mother’s risk to the same as a non-smoker);
• undergoing the combined screening test at 12 weeks’ gestation (regardless of whether or not she wants to screen for Down’s syndrome);
• getting to know her baby’s pattern of movements and reporting any significant reduction in movements to her midwife or maternity care provider.

Management of the pregnancy

If a baby is identified as SGA, doctors will consider how severely the baby is affected, and will put a treatment plan in place which will usually involve repeated ultrasound scans to monitor growth (as these scans are more reliable than measuring a woman’s abdomen, and show the pattern and trend of growth), examine the amount of water (liquor) around the baby and look at the blood flow through the umbilical cord. These scans check that growth is not slowing and look for other worrying features so that early delivery can be arranged if necessary.

If early delivery is needed, then babies may need steroids to reduce the risk of problems after birth, and mothers may need to be transferred to a maternity unit with appropriate special care facilities.

Problems with the delivery of care

While the majority of medical professionals provide a very high standard of care, there are occasions where mistakes are made and the results can be devastating. In 2016, a confidential inquiry found that screening for small babies was one of the most frequent areas of suboptimal care associated with stillbirth before labour.

Sadly, the errors that commonly lead to an avoidable stillbirth due to FGR could often easily be avoided with training and an understanding from maternity professionals of the potentially significant harm that can be caused by making such mistakes.

Helen Hammond, senior associate in the clinical negligence team at Penningtons Manches’ Basingstoke office, who specialises in cases arising from pregnancy and labour, comments: “There have been significant advances in the area of FGR over recent years but given the extremely close link between this and stillbirth, these must continue. Research into FGR needs to be accompanied by ongoing improvement of clinical protocols and training to ensure that those providing care do so to the very best of their abilities and that all those babies experiencing FGR are identified.”

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