Change of serum HPL level in maternal vein, umbilical cord vein and artery in mature and premature labour

Placental Lactogen as a Marker of Maternal Obesity, Diabetes, and Fetal Growth Abnormalities: Current Knowledge and Clinical Perspectives

Placental lactogen (PL) is a peptide hormone secreted throughout pregnancy by both animal and human specialized endocrine cells. PL plays an important role in the regulation of insulin secretion in pancreatic β-cells, stimulating their proliferation and promoting the expression of anti-apoptotic proteins. Cases of pregnancy affected by metabolic conditions, including obesity and diabetes, are related to alterations in the PL secretion pattern. Whereas obesity is most often associated with lower PL serum concentrations, diabetes results in increased PL blood levels. Disruptions in PL secretion are thought to be associated with an increased prevalence of gestational complications, such as placental dysfunction, diabetic retinopathy, and abnormalities in fetal growth. PL is believed to be positively correlated with birth weight. The impaired regulation of PL secretion could contribute to an increased incidence of both growth retardation and fetal macrosomia. Moreover, the dysregulation of PL production during the intrauterine period could affect the metabolic status in adulthood. PL concentration measurement could be useful in the prediction of fetal macrosomia in women with normal oral glucose tolerance test (OGTT) results or in evaluating the risk of fetal growth restriction, but its application in standard clinical practice seems to be limited in the era of ultrasonography.

A positive umbilical venous-arterial difference of leptin level and its rapid decline after birth

OBJECTIVE

We investigated the site of leptin production in the fetoplacental circulation.

STUDY DESIGN

We simultaneously determined plasma leptin levels in cord vessels and maternal peripheral veins of 38 healthy pregnant women. We also compared plasma leptin levels in 20 neonates at birth and on the fifth day after birth.

RESULTS

Leptin levels in cord vessels were significantly (p < 0.001) lower than those in maternal veins (mean 29.5 ng/ml). Leptin levels in umbilical arteries (mean 9.8 ng/ml) were significantly (p < 0.01) lower than those in umbilical veins (mean 12.9 ng/ml). Leptin levels in neonatal veins on the fifth day (mean 3.0 ng/ml) were markedly (p < 0.001) lower than those in umbilical arteries of the same neonates (mean 10.9 ng/ml).

CONCLUSION

The higher leptin levels in umbilical veins than in umbilical arteries and the marked decrease during the neonatal period suggest that the placenta is one of the major sources of leptin in the fetal circulation.