[Diagnostic image (332). A young woman with amenorrhoea]. / Diagnose in beeld (332). Een jonge vrouw met amenorroe.

A 16-year-old girl presented with amenorrhoea and a tense abdomen, due to a mature cystic teratoma with the characteristics ofa dermoid cyst.

Vitamin K1 levels and K1-dependent coagulation factors II and X in preterm and small-for-date neonates.

In 17 preterm neonates and 7 small-for-date neonates, all formula-fed, vitamin K-dependent coagulation factors II and X remained near 45% of adult values from the moment of birth until 28 days postnatally. Vitamin K1 levels, however, showed a remarkable rise from below the detection limit of 0.022 ng/ml in umbilical cord blood, to serum levels with a range of 0.99-7.29 ng/ml vitamin K1 on day 3, with a further rise on days 7 and 28 postnatally. Vitamin K1 (Konakion) parenterally given to a third group of four preterm neonates as a 1 mg dose resulted in very high serum levels of vitamin K1 (64.08-157.10 ng/ml), but without any significant increase in plasma levels of vitamin K-dependent coagulation factors II and X, compared to the group without any extra vitamin K1. It is concluded that in healthy preterm and small-for-date neonates no correlation is seen between serum levels of vitamin K1 and plasma levels of coagulation factors II and X. After administration of 1 mg Konakion no accelerated increase is seen in coagulation factor activities.

Vitamin K1 levels and coagulation factors in healthy term newborns till 4 weeks after birth.

Vitamin K1 serum levels were assessed by means of an off-line multidimensional liquid chromatography in 18 mothers, shortly after delivery, and in their healthy term infants. Umbilical cord and venous blood samples were assayed up to 4 weeks of life. Concurrently, levels of coagulation factors II and X, antithrombin III and platelets were established. Although the detection limit of the assay was as low as 22 pg/ml, vitamin K1 concentration appeared to be still beyond that level in cord blood or in newborn serum within 30 min after birth, whereas vitamin-K-dependent coagulation factors are already at a level of 40%, without evidence for the presence of descarboxy prothrombin, in any of the investigated neonates. After 3 days, breast-fed neonates had lower vitamin K1 levels than formula-fed infants (0.76 and 1.44 ng/ml, respectively). The levels of the vitamin-K-dependent coagulation factors II and X, however, were comparable, regardless of the kind of feeding. After 28 days, breast-fed neonates had even lower vitamin K1 levels (0.49 ng/ml, while the formula-fed infants showed higher vitamin K1 levels (4.45 ng/ml). But even then, the levels of vitamin-K-dependent coagulation factors II and X were comparable, regardless of the kind of feeding. From this we conclude that the serum levels of vitamin K1 in formula-fed neonates exceed those of breast-fed infants from the moment of feeding (24 h and later) without a concomitant rise in vitamin-K-dependent coagulation factors. A relationship between vitamin K1 levels and vitamin-K-dependent coagulation factors could not be established in healthy term breast-fed or formula-fed infants.

Quantitation of trans-vitamin K1 in small serum samples by off-line multidimensional liquid chromatography.

A sensitive high-performance liquid chromatography method for vitamin K1 using normal-phase fractionation was updated in order to cope with the limited volume of blood samples obtained from newborns. The method combines sample clean-up, normal-phase fractionation with reversed-phase chromatography using post-column electrochemical reduction and fluorescence detection. It was possible to measure vitamin K1 concentration in at least 0.2 ml of (potentially lipemic) serum even at a level of 0.3 nmol/l. The normal-phase method was compared to the updated method. The updated method shows about a twenty-fold lower limit of detectability than the previously described method.

Vitamin K1 in the newborn.

By a sensitive high-performance liquid chromatography method it was possible to measure vitamin K1 concentrations in mothers and their newborn children, even at a level of 0.5 nmol/l. All neonates were born after an uncomplicated and full-term pregnancy. The vitamin K1 concentration in neonates proved to be about half the value of their mothers, which is consistent with earlier studies of vitamin K1 dependent clotting factors. One may assume the existence of a partial placental barrier to vitamin K1. Venous, arterial and mixed cord blood did not differ significantly, so puncturing the vena umbilicalis is sufficient to measure vitamin K1 concentrations in cord blood.