Women who attend a hospital running the trial and fit the eligibility criteria below may be approached by their clinical team to participate. The women’s obstetrician or a member of the midwifery team will discuss the trial with the women and decide if they can and want to take part.

Who can take part?

  • Women aged 16 years or older.

  • Women with a twin pregnancy and a planned birth scheduled between 35+0 and 38+6 weeks gestation including women who have a planned birth due to logistic reasons (e.g. availability of beds or staff), parental preference or other maternal or fetal indications. Planned birth is defined as induction of labour or caesarean section.

  • Women with gestation established by scan at ≤16 weeks according to NICE guidelines and known chorionicity (how and if the babies share an amniotic sac or outer membrane).

  • ≥24 hours and <7 days until planned birth at time of starting on the trial.

Who can not take part?

  • Women who have a known or suspected major congenital fetal anomaly
  • Women who have received ACS within the seven days prior to taking part.
  • Women who have a sensitivity, contraindication or intolerance to any of the ACS or any of its excipients.
  • Women in whom chorionicity or gestational age are unknown.
  • Women with other serious pregnancy morbidities which indicate either birth before 35 weeks or urgent birth within 24 hours.

Indira and Sarah discuss STOPPIT3

What will happen during the trial?

Consent: Eligible women will be asked if they would like to participate. If they verbally agree to participate, they will be invited to attend the hospital prior to admission for planned birth. If they are still happy to participate, they will be asked to sign the trial consent form.

At most, we may ask women to attend the hospital twice for the trial; where possible, we will combine any visits needed for the trial with routine antenatal appointments to avoid extra appointments. However, combining the trial visit with routine visits may mean an overall extended visit.

Baseline data collection: Once consent is taken, information will be collected from the women’s medical records, including existing medical conditions, obstetric history and current pregnancy details. This information will be entered into the trial database by a research nurse/midwife. The online database will be managed and maintained by the University of Edinburgh.

Randomisation: We do not know if giving ACS is better than no treatment. To find out, we need to compare ASC and the placebo. We do this by putting people into groups and giving each group either ACS or placebo; the results are then compared to see if one is better. To make sure the groups are the same to start with, each participant is put into a group by chance (randomly). This is called randomisation. The results are then compared.

In STOPPIT-3, women will be randomised into one of two groups. There is approximately a 50:50 chance of being randomised into either group.

Corticosteroid Group: Two doses of ACS (Dexamethasone) by intramuscular injection (either to the thigh or buttock)


Placebo Group: Two doses of visually matching placebo (Sodium Chloride, also known as saline) by intramuscular injection (either to the thigh or buttock)

Randomisation Process

Patient Information Leaflet Video

The trial is a double-blind trial, so neither the women nor the doctor/medical team will know which treatment group they are in. However, this will not affect the women’s or babies’ clinical care.

Trial data collection: Information from the women’s and babies’ medical records will be entered into the trial database. This will include information about the birth and how the women and babies are after birth. We will collect data for 28 days after birth or discharge, whichever is sooner. All information collected will be in the women’s and babies’ medical records; we are not collecting anything additional. All the information we collect during the course of the research will be kept confidential.

We may follow up with a questionnaire when the babies are two years old to assess their development.

Our team is committed to making research in pregnancy inclusive. We use terms such as ‘women’, ‘maternity’, ‘breastfeed’ and so on, throughout our website, publications and social media accounts, to refer to those who are pregnant, give birth and/or use their breasts to feed a child. We acknowledge that not all people who are pregnant, give birth, and/or breastfeed a child identify as women. It is important that evidence-based care for maternity, perinatal and postnatal health is inclusive and tailored to an individual’s wishes.

Patient Information Sheet and Consent Forms are also available in other languages: Urdu, Gujurati, Polish, Arabic, Welsh, and Romanian.

Would you like to know more?