Higher levels of human placental lactogen and pregnancy-associated plasma protein A predicted earlier delivery, maybe because of better fetal growth, and higher levels of pregnancy-associated plasma protein A predicted better fetal growth.

Depressed pregnancy-associated plasma protein A (PAPP-A) concentrations have been found in patients with threatened abortion, often weeks before spontaneous abortion while the fetus was still alive. In order to extend these findings we have developed a highly sensitive PAPP-A radio-immunoassay and have established a reference range in early pregnancy for PAPP-A between week 7 and week 20 of pregnancy, based on blood samples from 240 pregnant women. The gestational age was determined by ultrasound. PAPP-A was measured in 128 women admitted to hospital because of vaginal bleeding in the 7th to 20th gestational week. The viability of the fetus was confirmed by ultrasonography. The serum values of PAPP-A were significantly lower (p = 0.002) in the group of women with vaginal bleeding than in the group of normally pregnant women. However, with regard to abortion later on, the predictive value of an abnormal blood test on admission was only 18.7%. Serial determinations showed increased PAPP-A values corresponding to the centile expected in the 12 women who aborted, as well as in the 116 women who gave birth. Consequently, the test is of no clinical value in the assessment of the prognosis in patients with symptoms of threatened abortion.

The decidualized endometrium produces secretory proteins of which secretory endometrial protein PP14 is the major product during the first trimester of pregnancy. The protein is secreted into the uterine lumen as well as into the peripheral blood. The purpose of this study was to examine whether decidual function, evaluated by the serum concentration of PP14, was different in women with early pregnancy bleeding compared to normal pregnant women. A reference range for serum PP14 was established on the basis of single samples from 236 normal pregnant women with ultrasonically confirmed gestational age. All the women were delivered of a normal child at term. The study comprised 128 pregnant women admitted because of vaginal bleeding between 6 and 18 weeks gestation. At ultrasonography, intrauterine fetal heart activity was either present or was confirmed at a subsequent examination. No difference was found in the serum level of PP14 compared to that in normal pregnancies, but women with vaginal bleeding and depressed PP14 levels appeared to have a 5-fold higher risk of preterm delivery than women with bleeding and normal PP14 levels.