The development of new screening tests based on better understanding of normal and abnormal placenta function may be crucial in reducing the incidence of stillbirths, according to a Seminar in The Lancet, this week’s edition.
Professor Gordon Smith, Department of Obstetrics and Gynecology, Cambridge University, UK, and Dr Ruth Fretts, Harvard Medical School, Boston, MA, USA, looked material published since 1997 while preparing for the Seminar.
The definition of fetal birth is the death of the baby/fetus at 22 weeks or more after gestation – or the death of a baby who weighs 500 g or more. Stillbirth is the most common way a potentially viable baby dies. Approximately one in every 200 pregnancies is affected by stillbirth. Stillbirth occurs twice as often as the death of a baby during his/her first month of its life (after it is born) – it is ten times more common than SIDS (Sudden Infant Death Syndrome), the authors explain.
Over the last few years there has hardly been any improvement in stillbirth rates. The researchers explain that the main reason for the is that the basic components of antenatal screening for the condition have remained virtually the same over the last four decades. Measuring uterus height with a tape measure is the mainstay of current screening in low risk women.
Outcomes have never improved when high tech methods, such as scanning all pregnant women later in pregnancy, were assessed.
The researchers believe that more than half of all stillbirths are most probably related to anomalous function of the placenta – the placenta may have separated before birth, pre-eclampsia could have developed, the baby might have grown inadequately, oxygen and/or nutrients may not have passed across the placenta properly. These events (late in the pregnancy) could be linked to abnormal development of the placenta early on during the pregnancy, even before the mother has received any antenatal care.
The authors argue that better understanding of the science behind placental function, or lack of good function, may lead to the development of new screening tests. Women who are apparently low-risk could be screened and those at risk of stillbirth would then be better identified.
Sadly, funding bodies do not seem to have given much priority to this area of medicine, despite the fact that stillbirth numbers have not changed for so long. No stillbirth charity currently funds research – this contrasts with charities involved with heart disease, diabetes, or cancer. Tackling this lack of funding must be a first step towards reducing the incidence of this devastating complication of pregnancy, the authors stress.
“Seminar׃ Stillbirth”
Prof Gordon CS Smith MD, Ruth C Fretts MD
The Lancet 2007; 370:1715-1725
DOI:10.1016/S0140-6736(07)61723-1
Written by׃ Christian Nordqvist