ICP linked to lower levels of vitamin K in small study
Researchers urge monitoring, supplementation
Women with intrahepatic cholestasis of pregnancy (ICP), the most common liver complication during pregnancy, are significantly more likely to have reduced blood levels of vitamin K than those without the condition, a small study showed.
These reduced levels were classified as vitamin K1 deficiency in about half of the women with ICP and fewer than 3% in those without ICP.
Vitamin K1 is a form of vitamin K mainly involved in blood clotting, which might explain why women with ICP were also found to lose a significantly higher amount of blood during vaginal birth.
“These findings collectively underscore the need for vigilant monitoring of coagulation [blood clotting] parameters in ICP patients and suggest that vitamin K supplementation could mitigate the risk of [bleeding] in those with confirmed vitamin K deficiencies,” the researchers wrote.
The study, “Comparative analysis of vitamin K levels in women with intrahepatic cholestasis of pregnancy,” was published in BMC Pregnancy and Childbirth.
Short-lived but risky condition
ICP is a form of cholestasis, a condition marked by slowed flow of bile from the liver to the intestines, that occurs during pregnancy. Bile is essential for the absorption of fatty molecules and fat-soluble vitamins.
Cholestasis causes bile acids, the main component of bile, to accumulate to toxic levels in the liver and leak into the bloodstream, causing cholestasis symptoms such as itching. It can also result in deficient levels of fat-soluble vitamins, which can affect a number of body processes.
While ICP usually resolves shortly after birth, it carries significant risks for both the mother and fetus, including preterm birth (before 37 weeks of gestation), stillbirth, and maternal bleeding. The risk of bleeding is particularly higher in pregnant women with a deficiency in vitamin K, a fat-soluble vitamin essential for blood clotting.
Vitamin K has two main forms, K1 and K2. The first, found in green, leafy vegetables, is involved mainly in blood clotting and bone metabolism. Vitamin K2, found in certain animal products, appears to be involved in heart health, in addition to blood clotting and bone health.
To know more about the relationship between ICP and vitamin K, and its implication in bleeding during birth, a team of researchers in Moldova followed 44 pregnant women with ICP and 44 pregnant women without the condition.
All were pregnant for more than 22 weeks (about 5.5 months), and ICP diagnosis was confirmed by the presence of itching and elevated blood levels of bile acids.
Women with ICP tended to be older than those without ICP (average age 30.1 vs. 28.1), and had significantly higher blood levels of bile acids (49.7 micromol/L vs. 3.2 micromol/L). Based on bile acid levels, more than half of the women with ICP (54.5%) were classified as having mild disease, 34.1% had moderate disease, and 11.4% had severe disease.
Results showed that mean blood levels of vitamin K were within the normal range in both groups. However, women with ICP had significantly lower levels of vitamin K1 (0.15 micrograms [mcg]/L vs. 0.29 mcg/L) and K2 MK7, a specific form of vitamin K2 thought to be involved in bone and cardiovascular health (0.17 mcg/L vs. 0.26 mcg/L).
Also, a significantly higher proportion of women with ICP had vitamin K1 deficiency compared with the control group (52.3% vs. 2.3%). Rates of deficiency in vitamin K2 MK7 were comparable between the groups.
Women with ICP were significantly less likely to have normal levels of all vitamin K forms (38.6% vs. 79.5%).
The findings “demonstrate an association between intrahepatic cholestasis of pregnancy and vitamin K1 deficiency, reinforcing the hypothesis that bile acid malabsorption in ICP disrupts the absorption of fat-soluble vitamins, including vitamin K,” the researchers wrote.
The International Normalized Ratio (INR), reflecting how fast the blood clots, was significantly lower in the ICP group, but values were still within the normal range. One woman in each group had an abnormal blood coagulation profile.
Most women in both groups gave birth by vaginal delivery, but these births were significantly less frequent in women with ICP (56.8% vs. 72.7%). Blood loss during vaginal birth was higher in the ICP group (mean of 351 mL vs. 297 mL). There were no significant group differences in terms of blood loss among those undergoing cesarean section.
The data suggest that “the coagulation impairments related to Vitamin K deficiency may exacerbate bleeding risks” in women with ICP, the team wrote.
Although the findings suggest that vitamin K supplementation may reduce the risk of bleeding during delivery, “further research is warranted to explore the long-term benefits of vitamin K supplementation and its impact on both maternal and fetal outcomes in ICP,” the researchers wrote.
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