Boots WebMD Partners in Health
Return To Boots

Pregnancy health centre


BMJ Group Medical Reference

Progesterone is a natural chemical that your body makes. It's one of the main female hormones. Taking a man-made version of this hormone (a progestogen) may help to prevent premature births for some women.

In most of the studies of this treatment, women at risk of a premature birth were given the hormone as an injection. In other studies, women took it as a type of pill that they put in their vagina (a pessary).

A review of the research found that: [18]

  • About 36 in 100 women who took a progestogen gave birth prematurely

  • About 43 in 100 women who took a dummy treatment (a placebo) gave birth early.

Women who took a progestogen were also less likely to have a baby with a low birth weight. [18]

Three summaries of the research found that a progestogen helped to prevent premature birth in women who had a short cervix (the opening of the womb) or in women who had had a previous premature birth. [18] [19] [20]

But progestogen does not seem to reduce the risk for women having twins or multiple births. [21] [22] [23] [24] And it may not help for very early premature births, before 34 weeks. [25]

One of the summaries of research found that babies were less likely to have bleeding in the brain ( haemorrhage) if their mothers took progestogen. But there was no evidence of more breathing problems in the babies of women who had progestogen. [18]

The research hasn't found any serious side effects of progestogen injections. However, there haven't been any studies of the long-term effects of this treatment in mothers or babies. We need more research to know how safe this treatment is in the long term.

Last Updated: August 15, 2013
This information does not replace medical advice.  If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.

Popular slideshows & tools on BootsWebMD

woman looking at pregnancy test
Early pregnancy symptoms
donut on plate
The truth about sugar addiction
smiling african american woman
Best kept secrets for beautiful hair
couple watching sunset
How much do you know?
nappy being changed
How to change your baby's nappy
woman using moisturizer
Causes and home solutions
assorted spices
Pump up the flavour with spices
bag of crisps
Food cravings that wreck your diet
woman with cucumbers on eyes
How to banish dark circles and bags
probiotic shakes
Help digestion
polka dot dress on hangar
Lose weight without dieting