A large-scale study from China has found that women with low blood sugar levels before pregnancy may face a higher risk of complications such as preterm birth and low birth weight. Both high blood sugar (hyperglycemia), commonly seen in prediabetes and type 2 diabetes, and low blood sugar (hypoglycemia) are known to pose risks. Earlier studies have shown that high blood sugar before or during pregnancy increases the risk of complications, and that low blood sugar during pregnancy is also linked to adverse outcomes. However, it was unclear whether low blood sugar before pregnancy posed risks for women without pre-existing diabetes. The study found that women with low blood sugar pre-pregnancy had higher risks of adverse pregnancy outcomes, including preterm birth, low birth weight, and birth defects.