Condition category
Pregnancy and Childbirth
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Women with type 1 diabetes are up to four times more likely to develop high blood pressure during pregnancy (pre-eclampsia) when compared to a woman without diabetes. A recent study suggested that taking vitamin C and Vitamin E supplements may prevent women from developing pre-eclampsia, but this needs to be confirmed in larger studies. This is a study to find out if taking vitamin E and vitamin C supplements during pregnancy can prevent pre-eclampsia in women who have type 1 diabetes.

Who can participate?
The DAPIT study aims to recruit about 756 women with type 1 diabetes, over 16 years of age, from NHS antenatal-metabolic clinics across Northern Ireland, North West England and Scotland.

What does the study involve?
Women who take part in the study will be given 2 capsules to take each day throughout pregnancy. These may contain vitamin C and vitamin E or may be dummy (placebo) capsules. Neither the woman nor the doctor looking after her will know whether she is receiving vitamins or dummy tablets. Half of the patients in the study will receive vitamins, and the other half will receive placebo. Women will attend antenatal clinic every 2 weeks throughout pregnancy as normal, will be asked to complete a short (15 minutes) questionnaire about their diet after 26 weeks of pregnancy, and an extra blood sample will be taken at the first visit and after 26 and 34 weeks of pregnancy to measure levels of vitamins and biochemical markers which may be linked to pre-eclampsia. After pregnancy, we would like to assess the health of the baby at a routine post-natal visit which will occur approximately 6 weeks after delivery. This assessment will include measurement of height, weight and head circumference and assessment of development as well as a normal clinical examination.

What are the possible benefits and risks of participating?
For women who receive vitamin C and vitamin E during the study, it is possible that their risk of developing pre-eclampsia may be reduced. However, we do not know if this is the case. The information we get from this study may help us to treat pregnant patients with diabetes better. In particular, it will allow us to decide in the future whether all pregnant women with diabetes should be recommended to take vitamin supplements or whether this is a waste of time. The main disadvantage of taking part in the study is the need to take two capsules once per day. In addition, women will be asked to complete an additional dietary questionnaire as described above and to provide three blood samples during the course of your pregnancy.

Where is the study run from?
Queen's University Belfast and Belfast Health and Social Care Trust.

When is the study starting and how long is it expected to run for?
Recruitment started in 2003 and ended in 2008.

Who is funding the study?
The Wellcome Trust (UK).

Who is the main contact?
Professor David McCance

Trial website

Contact information



Primary contact

Dr David McCance


Contact details

Regional Centre for Endocrinology and Diabetes
Royal Victoria Hospital
The Royal Group of Hospitals and Dental Hospital Health and Social Services Trust
Grosvenor Road
BT12 6BA
United Kingdom
+44 (0)28 9063 3430

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A randomised controlled trial of vitamins C and E to prevent pre-eclampsia in type one diabetic pregnancy


DAPIT- the Diabetes And Pre-eclampsia Intervention Trial

Study hypothesis

Double-blind randomised multicentre placebo-controlled trial of Vitamin C 1000 mg and Vitamin E 400 IU or placebo tablets daily from eight to 22 weeks gestation until delivery to determine whether supplementation with vitamin C and vitamin E from early pregnancy will reduce the risk of developing pre-eclampsia in pregnant women with type one diabetes.

On 11/06/2008 the overall trial end date was changed from 30/09/2007 to 31/01/2009.

Ethics approval

West Midlands Multi-centre Research Ethics Committee, 09/09/2002, ref: MREC/02/7/16

Study design

Double-blind randomised multicentre placebo-controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet




Vitamin C 1000 mg and vitamin E 400 IU or placebo daily from recruitment (eight to 22 weeks gestation) until delivery.

Intervention type



Not Specified

Drug names

Vitamin C 1000 mg and Vitamin E 400 IU

Primary outcome measure

Incidence of pre-eclampsia, measured after delivery

Secondary outcome measures

1. Endothelial activation, measured at baseline, 26 weeks gestation and 34 weeks gestation
2. Birthweight centile, measured after delivery

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Women with type one diabetes preceding pregnancy presenting before 22 weeks gestation

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Warfarin treatment
2. Multiple pregnancy
3. Gestational diabetes
4. Current or previous (within the last six weeks) ingestion of preparations containing vitamin C (more than 500 mg/day) or vitamin E (200 IU/day)

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Regional Centre for Endocrinology and Diabetes
BT12 6BA
United Kingdom

Sponsor information


The Royal Group of Hospitals and Dental Hospital Health and Social Services Trust (UK)

Sponsor details

Royal Research Office
First Floor
Education Centre
Royal Victoria Hospital
Grosvenor Road
BT12 6BA
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Wellcome Trust

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

International organizations


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2004 protocol at:
2. 2010 results in:
3. 2015 results in:

Publication citations

  1. Protocol at

    Holmes VA, Young IS, Maresh MJ, Pearson DW, Walker JD, McCance DR, , The Diabetes and Pre-eclampsia Intervention Trial., Int J Gynaecol Obstet, 2004, 87, 1, 66-71, doi: 10.1016/j.ijgo.2004.06.015.

  2. Results

    McCance DR, Holmes VA, Maresh MJ, Patterson CC, Walker JD, Pearson DW, Young IS, , Vitamins C and E for prevention of pre-eclampsia in women with type 1 diabetes (DAPIT): a randomised placebo-controlled trial., Lancet, 2010, 376, 9737, 259-266, doi: 10.1016/S0140-6736(10)60630-7.

  3. Results

    Maresh MJ, Holmes VA, Patterson CC, Young IS, Pearson DW, Walker JD, McCance DR; Diabetes and Pre-eclampsia Intervention Trial Study Group, Glycemic targets in the second and third trimester of pregnancy for women with type 1 diabetes, Diabetes Care, 2015 , 38, 1, 34-42, doi: 10.2337/dc14-1755.

Additional files

Editorial Notes