Serum concentrations of hCG were determined in blood samples taken 18-20 h and immediately before vacuum aspiration in 45 women in gestational weeks 7-9, admitted for legal abortion. In 35 of the women, a laminaria tent was inserted for cervical dilatation immediately after the first blood sampling. Serum hCG values decreased significantly in the women pretreated with laminaria tent, but were unchanged in the untreated women. This finding may indicate that pretreatment with a laminaria tent induces a partial placental detachment.
PIP: At the Karolinska Institute at Huddinge University Hospital in Huddinge, Sweden, serum levels of human chorionic gonadotropin (hCG) in 35 patients who had been inserted with a laminaria tent 18-20 hours prior to and immediately after vacuum aspiration were compared with those of 10 women who chose not to have laminaria tents inserted prior to vacuum aspiration. Gestational age ranged from 7 to 9 weeks. All the pregnant women were primiparous. The mean serum hCG values did not differ greatly between the cases and controls (84,260 U/1 and 75,878 U/1, respectively). Yet the mean serum hCG levels of women treated with laminaria tents to induce dilation fell considerably more than those in the control group (76,468 U/1 vs. 84,939 U/1; p.01). The concentrations fell in all treated women. Since serum hCG values normally increase during this period, the decrease indicated that laminaria tents induced partial detachment of the placenta. The results also explained the significant bleeding and/or presence of placental tissue in the cervical canal. These results suggest that laminaria tents cause partial placental detachment as well as labor contractions.