Diabetes in pregnancy: are we providing the best care ... - HQIP

4. Methodology
4.1 Introduction
The enquiry module of the CEMACH diabetes programme encompassed a case-control study,
a comparison of type 1 and type 2 diabetes, and an audit of care:
• A case-control analysis to examine any differences in demographic factors, social and lifestyle
issues, and clinical care between a) pregnancies resulting in adverse pregnancy outcome (deaths
from 20 weeks gestation up to 28 days after delivery or major fetal congenital anomaly at any
gestation) and b) pregnancies resulting in a normally formed baby surviving to 28 days of life.
• A comparison of any differences in demographic factors, social and lifestyle issues, and clinical
care between women with a) type 1 and b) type 2 diabetes.
• An audit of the care received before, during and after pregnancy by a subset of women within
the whole study population of the CEMACH diabetes programme.
4.2 Selection of pregnancies for enquiry
To enable the audit of care and case-control analysis to be conducted, four groups of pregnancies were
selected for enquiry:
1. Anomalies – pregnancy to a woman with type 1 or type 2 diabetes resulting in a singleton baby
(including terminations of pregnancy at any gestation, late fetal losses, stillbirths and live births)
with a confi rmed major congenital anomaly, diagnosed up to 28 days of life.
2. Deaths – pregnancy to a woman with type 1 or type 2 diabetes resulting in death of a singleton baby
from 20 weeks of gestation up to 28 days after delivery, excluding terminations of pregnancy and
confi rmed congenital anomalies.
3. Controls – pregnancy to a woman with type 1 or type 2 diabetes resulting in a singleton birth
delivering at 20 weeks of gestation onwards and surviving to 28 days of life, excluding those with
a confi rmed congenital anomaly.
Preliminary fi ndings from the CEMACH descriptive study of 3808 pregnancies to women with diabetes
in England, Wales and Northern Ireland in 2002-03 showed that women with type 2 diabetes appeared
to be more poorly prepared for pregnancy and also had an equivalent risk of adverse pregnancy
outcome to women with type 1 diabetes. 1,2 It was therefore decided to enquire on an additional sample
of pregnancies of women with type 2 diabetes to enable a more thorough investigation of the care
received by these women.
4. Additional type 2 sample – pregnancy to a woman with type 2 diabetes resulting in a singleton
birth delivering at 20 weeks of gestation onwards and surviving to 28 days of life, excluding those
with a confi rmed congenital anomaly.
All pregnancies meeting the defi nition of anomaly or death within the CEMACH descriptive study were
selected to form the cases for the case-control analysis. Controls were randomly sampled from the
group of pregnancies reported in the CEMACH descriptive study fi tting the defi nition of a control in
order to sample one control per case. The additional type 2 pregnancies were randomly sampled from
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