Findings from a UK-led international trial, funded by the Medical Research Council, confirm that premature babies across Europe are being delivered at the right time to save their lives, but preventing brain damage by optimising delivery time is still a challenge.
Doctors routinely use a number of tests to determine the health of an unborn baby but uncertainties remain over exactly when to deliver the baby if there are problems. The dilemma for doctors is whether to try and allow the baby to mature as much as possible in the womb to improve chances of survival and to avoid cerebral palsy, or to deliver early to prevent problems in brain development caused by a later lack of oxygen.
The MRC Growth Restriction Intervention Trial (GRIT) is the first to assess the impact of different delivery times for premature babies on survival and brain development.
Women were randomised into a ‘deliver now’ group which had to deliver within 48 hours, or a ‘defer delivery’ group for whom delivery was delayed as long as possible.
Overall there were no differences in death rates between the two groups or in overall brain development, assessed when the children were two years old. However the rate of disability (mainly cerebral palsy) at age two, was slightly higher in the ‘deliver now’ group with 21 out of 290 babies disabled, compared with 12 out of 283 in the ‘defer delivery’ group. Further research will be needed to confirm this trend. However, the results suggest that in the meantime it would be best to err on the side of caution and delay delivery where possible.
The eight year study was led by Dr Jim Thornton, Professor of Obstetrics and Gynaecology at Nottingham City Hospital and The University of Nottingham. It involved 548 women and 588 babies from 69 hospitals across 13 European countries.
The women were between 24 and 36 weeks into their pregnancy and entered into the study if tests confirmed they were experiencing problems with the baby and where there was clinical uncertainty about whether to deliver.
The children were traced for follow up at two years to see if the child had survived and if so, the child’s doctor was asked to complete a questionnaire about current health to assess disability. This was determined by the presence of problems such as cerebral palsy, little or no vision or whether the child used a hearing aid. Children were also examined and assessed using the Griffith developmental quotient. This is a type of baby IQ test.
Jim Thornton said: “There has to be an element of best judgement in these situations and hopefully our results will give doctors better information to make those crucial decisions. Our results indicate that these children are being delivered at about the right time to save their lives, but the greater rate of brain damage in the ‘deliver now’ group suggests it would be better to delay where possible, to minimise brain damage - as long as waiting isn’t more harmful.”
“We will continue following the children up until they are aged about nine years old. This will let us look more carefully at whether there are any other problems later in life associated with the timing of delivery. In the meantime this research is already changing clinical practice.”
Professor Colin Blakemore, Chief Executive of the MRC, said: “This is an excellent example of a trial to evaluate the risks and benefits of different healthcare interventions. The MRC, along with other publicly funded bodies, is uniquely placed to carry out this type of research, the results of which directly affect the treatment of patients.”