More than 8,000 more babies could be born each year if women with a history of miscarriages were given a hormone in their next pregnancy, research suggests.
Experts say women with a history of miscarriage, who have early bleeding in their pregnancy, could benefit from progesterone.
Researchers suggest there are scientific and economic advantages to giving a course of self-administered twice daily progesterone to women from when they first present with early pregnancy bleeding up until 16 weeks of pregnancy to prevent miscarriage.
Progesterone is naturally secreted by the ovaries and placenta in early pregnancy and is vital to the attainment and maintenance of healthy pregnancies.
Experts from the University of Birmingham and Tommy’s National Centre for Miscarriage are calling for women at risk to be given the hormone as a standard by the NHS.
They suggest progesterone can increase women’s chances of having a baby, resulting in 8,450 more babies being born each year.
Between 20% and 25% of pregnancies end in a miscarriage, having a major clinical and psychological impact on women and their families.
The first of the new studies, published in the American Journal of Obstetrics and Gynaecology, examines the findings of two major clinical trials – Promise and Prism.
Promise studied 836 women with unexplained recurrent miscarriages at 45 hospitals in the UK and the Netherlands, and found a 3% higher live birth rate with progesterone, but with substantial statistical uncertainty.
While Prism studied 4,153 women with early pregnancy bleeding at 48 hospitals in the UK.
It found a 5% increase in the number of babies born to those who were given progesterone who had previously had one or more miscarriages, compared to those given a placebo.
According to the research, the benefit was even greater for women who had previous recurrent miscarriages – three or more – with a 15% increase in the live birth rate in the progesterone group.
The second of the studies, published in BJOG: an international Journal of Obstetrics and Gynaecology, looks at the economics of the Prism trial.
It indicates progesterone is cost-effective, costing on average £204 per pregnancy.
Tracy Roberts, professor of economics at the University of Birmingham, said miscarriage costs the NHS around £350 million per year.
An unpublished survey by the University of Birmingham of 130 healthcare practitioners in the UK found that before the results of the Prism study just 13% offered women at threat of miscarriage progesterone.
While post publication of the results in the New England Journal of Medicine in May 2019, 75% now offer the treatment.
Dr Adam Devall, senior clinical trial fellow at the University of Birmingham and manager of Tommy’s National Centre for Miscarriage Research, said: “We believe that the dual risk factors of early pregnancy bleeding and a history of one or more previous miscarriages identify high risk women in whom progesterone is of benefit.
“The question is, how should this affect clinical practice?”
Dr Pat O’Brien, consultant and vice president of The Royal College of Obstetricians and Gynaecologists, said: “We welcome the findings from this well-researched trial which supports the use of progesterone among women with early pregnancy bleeding and a history of miscarriage.
“This treatment offers an increased chance of a successful birth and appears to be cost effective for the NHS, so we hope Nice will consider this important research in their next update of the guidance.”
The research was funded by the National Institute for Health Research (NIHR).
A spokeswoman for the National Institute for Health and Care Excellence (Nice), said: “We are currently updating our guideline on the diagnosis and initial management of ectopic pregnancy and miscarriage to consider new evidence on progesterone in treating threatened miscarriage.
“These updated recommendations will be subject to consultation in due course.”