Ultrasonic appearance probably indicative of imminent fetal death.

Ultrasonic appearance probably indicative of imminent fetal death One of the difficulties in recognising fetal death by ultrasonic scanning in early pregnancy is that the negative finding of no fetal heart movement must always be less convincing than a positive finding. Furthermore, Robinson' found only one instance of irregularity of the fetal heart in ten cases scanned before their pregnancies became missed abortions, and he concluded that it was not yet possible to predict fetal death by sonar. I report an ultrasonic appearance that I have noted on at least 14 occasions always in association with subsequent fetal death. Case reports Case 1-A 33-year-old housewife had had one previous pregnancy 21 years earlier. She was first seen in the current pregnancy 12 weeks after her last menstrual period. Two weeks later she had a slight brownish vaginal discharge, and on clinical examination her uterus was felt to be small for dates. She was therefore referred for ultrasonic scanning. The scan was performed 14 weeks after her last period using a Diasonagraph NE 4102 (Nuclear Enterprises, Edinburgh) with a sound frequency of 2-5 MHz and pulse repetition frequency of 600 Hz. Fetal crown rump length was only 50 mm, and a fine vibration was noted originating from the region of the fetus (figure). The vibration was intermittent and variable in rate but about 1200-1500 Hz. On repeat scan three days later no fetal heart movement or vibration could be detected. An assay of the serum concentration of the 3 subunit of human chorionic gonadotrophin gave an inappropriately low value and it was decided to evacuate the uterus surgically. This was carried out four days later, the products being histologically compatible with a missed abortion. Case 2-A 27-year-old housewife was referred for termination ofpregnancy. An ultrasonic scan (details as in case 1) carried out seven weeks after her last menstrual period showed an intrauterine gestational sac containing a fetus with a crown rump length of 14-7 mm. The fetal heart movement was easily detected and had a rate of 150 beats/min. Termination of the pregnancy was agreed and, with the patient's consent, it was decided to perform this by the intravaginal administration of a pessary containing an ester of 15-methyl-prostaglandin F2o. As part of the trial of the abortion method further ultrasonic scans were performed seven hours after insertion of the pessary and two days later. On the earlier of these scans …