Association between pregnancy-associated plasma protein-A levels in the first trimester and gestational diabetes mellitus in Chinese women

Introduction: Several studies have shown that women with pre-existing diabetes mellitus have significantly lower pregnancy-associated plasma protein-A levels than those without. This study aimed to evaluate whether first-trimester pregnancy-associated plasma protein-A multiple of median is associated with gestational diabetes mellitus in Chinese pregnant women.

Methods: This prospectively collected case series was conducted in a regional hospital in Hong Kong. All consecutive Chinese women with a singleton pregnancy who attended the hospital for their first antenatal visit (before 14 weeks' gestation) from April to July 2014 were included. Pregnancy-associated plasma protein-A multiple of median was compared between the gestational diabetic (especially for early-onset gestational diabetes) and non-diabetic groups. The correlation between pregnancy-associated plasma protein-A level and glycosylated haemoglobin level in women with gestational diabetes was also examined.

Results: Of the 520 women recruited, gestational diabetes was diagnosed in 169 (32.5%). Among them, 43 (25.4%) had an early diagnosis, and 167 (98.8%) with the disease were managed by diet alone. The gestational diabetic group did not differ significantly to the non-diabetic group in pregnancy-associated plasma protein-A (0.97 vs 0.99, P=0.40) or free β-human chorionic gonadotrophin multiple of median (1.05 vs 1.02, P=0.29). Compared with the non-gestational diabetic group, women with early diagnosis of gestational diabetes had a non-significant reduction in pregnancy-associated plasma protein-A multiple of median (median, interquartile range: 0.86, 0.57-1.23 vs 0.99, 0.67-1.44; P=0.11). Pregnancy-associated plasma protein-A and glycosylated haemoglobin levels were not correlated in women with gestational diabetes (r=0.027; P=0.74).

Conclusions: Chinese women with non-insulin-dependent gestational diabetes did not exhibit significant changes to pregnancy-associated plasma protein-A multiple of median nor a correlation between pregnancy-associated plasma protein-A with glycosylated haemoglobin levels. Pregnancy-associated plasma protein-A multiple of median was not predictive of non-insulin-dependent gestational diabetes or early onset of gestational diabetes. There was a high prevalence of gestational diabetes in the Chinese population.