Researchers in Britain looked at factors that affected poor pregnancy outcomes in a group of women with diabetes from England and Wales who participated in the National Pregnancy in Diabetes Audit. This project used data from 172 pregnancy clinics, and included outcomes such as preterm delivery (before 37 weeks of gestation), large birth weight for gestational age (higher than 90% of births), congenital anomalies (birth defects), stillbirth and death of the newborn. The researchers compared these outcomes with several factors — some of them related to diabetes — including A1C (a measure of long-term blood glucose control), body-mass index (BMI, a measure of weight that takes height into account), pre-pregnancy healthcare, age, ethnicity and diabetes duration.
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The study included a total of 15,290 pregnant women with diabetes, with almost perfectly equal numbers of those with type 1 and type 2. For women with type 1, the median age at delivery was 30, and the median duration of diabetes was 13 years. For women with type 2, the median age at delivery was 34, and the median duration of diabetes was 3 years. The rate of preterm delivery was 42.4% in women with type 1, and 23.4% in women with type 2. A large birth weight for gestational age was seen in 52.2% of women with type 1, and 26.2% of women with type 2. Congenital anomalies were seen in 44.8 per 1,000 live births, pregnancy terminations and fetal losses in women with type 2, while the equivalent number for type 1 was 40.5 per 1,000. Stillbirth occurred in 10.4 per 1,000 births for type 1 diabetes, and 13.5 per 1,000 births for type 2. The rate of death among newborn babies was 7.4 per 1,000 live births for type 1 diabetes, and 11.2 per 1,000 live births for type 2.
Several factors related to poor outcomes
The researchers found that a number of factors were tied to poor pregnancy-related outcomes. An A1C level of 6.5% or higher during the third trimester of pregnancy was linked to over three times the rate of either stillbirth or death in a newborn, compared with an A1C level below 6.5%. Having type 2 diabetes, rather than type 1, was also linked to a 65% higher risk of either stillbirth or death in a newborn. A large birth weight for gestational age was linked to greater age, longer diabetes duration and a higher BMI.
The researchers concluded that these numbers “highlight persistent adverse pregnancy outcomes in women with type 1 or type 2 diabetes,” with some outcomes affected by factors that can potentially be modified — such as A1C and BMI — but other factors completely beyond the control of pregnant women with diabetes. The results were very similar across all pregnancy clinics in the study, suggesting that poor outcomes occur in highly predictable patterns — which means that women with an especially high risk for certain outcomes could be screened for and given special attention when needed. More research is necessary, though, to come up with comprehensive screening procedures for women with diabetes that include factors like diabetes type, BMI and diabetes duration.
Want to learn more about women’s health and diabetes? Read “Top 10 Health Tips for Women Over 65,” “Diabetes and Chronic UTIs: Questions and Answers,” and “Pregnancy and Type 1 Diabetes.”
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