Contractile Activity in the Human Uterine Cervix and Corpus During Cervical Dilatation by Laminaria Tent in First Trimester Legal Abortions

Millar microtransducers were used in 7 patients to record contractile variations in the cervix and corpus during dilatation of the cervical canal by Laminaria tent preceding first-trimester vacuum aspiration. The spontaneous contractile activity was registered in a control group of 5 patients without laminaria pretreatment. Two Millar catheters were used. The sensor tip of one Millar catheter was placed extra-amniotically in the uterine cavity, and the other one in the mid-cervical canal. Both sensor tips faced the wall of the cervix and corpus. The study showed that laminaria tents not only have a gentle dilatating effect on the cervix, but also induce painless uterine contractions, of amplitudes reaching 20 mmHg, and increased contractile activity in the cervix for the duration of dilatation.