Growth Assessment Protocol (GAP)

The Perinatal Institute offers GAP as a comprehensive program with a service level agreement which can be viewed here: GAP SLA

Our Terms of Service are set out here.

GAP Guidance

The GAP Care Pathway is aligned with and complementary to the Fetal Growth element of the NHS Saving Babies Lives' Care Bundle v3.
It is available here: GAP Guidance

GAP E-Learning

To access the E-Learning portal please use the following link: GAP-Elearning

GAP is based on the following key elements:

Evidence based care pathway and risk assessment algorithms
Training and accreditation of all staff involved in clinical care
Implementation of customised GROW chart and audit tool
Rolling audit, reporting and benchmarking of performance

Resources

GAP training: dates of forthcoming workshops are listed here.

SFH - Standardised fundal height measurement video.

GROW 2.0: Upgrade to electronic chart and recording system

Recent abstracts presented by the Perinatal Institute:

RCOG June 2025: https://perinatal.org.uk/rcog_congress_2025_abstracts

BMFMS May 2025: https://perinatal.org.uk/bmfms_2025_abstracts

BMFMS April 2024: https://perinatal.org.uk/bmfms_2024_abstracts

RCOG June 2023: https://www.perinatal.org.uk/rcog_congress_2023_abstracts

Publications

Small-for-gestational age according to INTERGROWTH-21st fetal weight standard misses most pregnancies at risk of stillbirth identified by GROW. Ultrasound Obstet Gynecol. 2025 https://doi.org/10.1002/uog.29214
Accuracy of antenatal ultrasound in predicting large-for-gestational-age babies: population-based cohort study. Am J Obstet Gynecol. 2024;S0002-9378(24):00578–7. https://doi.org/10.1016/j.ajog.2024.04.052
Fetal size vs growth: comparative analysis of 3 models of growth velocity based on third trimester estimated fetal weights for identifying stillbirth risk. Am J Obstet Gynecol. 2023;S0002-9378(23):02188–9. https://doi.org/10.1016/j.ajog.2023.12.029
Stillbirth risk and SGA according to Hadlock, Intergrowth-21st, WHO and GROW fetal weight standards: analysis by maternal ethnicity and BMI. Am J Obstet Gynecol. 2023;229(5): 547.e1-547.e13. https://doi.org/10.1016/j.ajog.2023.05.026
Outcome-based comparative analysis of five fetal growth velocity models to define slow growth Ultrasound Obstet Gynecol. 2023;62(6):805-12. https://doi.org/10.1002/uog.26248
Evaluating the Growth Assessment Protocol for stillbirth prevention: progress and challenges J Perinatal Med. 2022;50(6): 737-47. https://doi.org/10.1515/jpm-2022-0209
Reduction of stillbirths in England from 2008 to 2017 according to uptake of the Growth Assessment Protocol: 10‐year population‐based cohort study Ultrasound Obstet Gynecol. 2021;57:401-8. https://doi.org/10.1002/uog.22187
Understanding and Preventing Stillbirth: A Global Task Special Issue of Journal of Perinatal Medicine, 2022. https://www.degruyterbrill.com/journal/key/jpme/50/6/html
Prospective risk of stillbirth according to fetal size at term J Perinatal Med. 2022;50(6): 748-52. https://doi.org/10.1515/jpm-2022-0200
A fetal weight projection model to define growth velocity, and validation against pregnancy outcome in a cohort of serially scanned pregnancies Ultrasound Obstet Gynecol. 2022;60(1):86-95. https://doi.org/10.1002/uog.24860
Customized GROW vs INTERGROWTH-21st birthweight standards to identify small for gestational age associated perinatal outcomes at term Am J Obstet Gynecol MFM. 2022;4(2):100545. https://doi.org/10.1016/j.ajogmf.2021.100545
Customized growth charts: rationale, validation and clinical benefits Am J Obstet Gynecol. 2018;218(2S):S609-18. https://doi.org/10.1016/j.ajog.2017.12.011
Fetal growth surveillance – Current guidelines, practices and challenges Ultrasound. 2018;26(2):69-79. https://doi.org/10.1177/1742271X18760657
Customized vs INTERGROWTH-21st standards for the assessment of birthweight and stillbirth risk at term Am J Obstet Gynecol. 2018;218(2S):S692-9. https://doi.org/10.1016/j.ajog.2017.12.013
Preventing stillbirths through improved antenatal recognition of pregnancies at risk due to fetal growth restriction Public Health 2014; 128:698-702. http://dx.doi.org/10.1016/j.puhe.2014.06.022
Association between reduced stillbirth rates in England and regional uptake of accreditation training in customised fetal growth assessment BMJ Open 2013;3:e003942 https://doi.org/10.1136/bmjopen-2013-003942
The Growth Assessment Protocol: a national programme to improve patient safety in maternity care MIDIRS, 2013; 23:516-23. http://www.perinatal.org.uk/fetalgrowth/gap/Resources/GAP_article_MIDIRS_Dec_2013.pdf
Tackling Stillbirth: simple and cheap techniques could save hundreds of babies a year The Times Leading Article 18.12.2013
Fetal growth screening by fundal height measurement Best Practice & Research Clin Obstet Gynaecol https://doi.org/10.1016/j.bpobgyn.2009.09.004

ONS stillbirth rates in England

According to ONS figures, stillbirth rates in England have fallen consistently
for 9 years to their lowest point of 3.80/1000 in 2020. This represents a 29.0% reduction from the 2000-09 (10 year) average of 5.35, and equates to 1,022 babies saved per year.

Our 10 year, unit level analysis (doi.org/10.1002/uog.22187) showed

an overall decline, associated with better protocols and awareness;
Trusts that fully implemented the GAP programme achieved a larger reduction; and
the steepest drop was observed in GAP units with the highest SGA detection rates

There was a flattening of the downward trend during the pandemic in 2020 and a sharp increase in 2021. Since then, stillbirth rates have remained at a level above the low-point reached before the pandemic.