MONO-AMNIOTIC TWIN PREGNANCY BY

JOHN HENDERSON, M.B., M.R.C.O.G. Senior Registrar, Raigmore Hospital, lnverness

THS is a rare condition, there being only 3 previous cases reported in the British literature (Newman, 1858; Adamson, 1896; Frewer, 1936).

CASE REPORT Mrs. A. M., aged 23 years, had had one

previous normal pregnancy. She attended the antenatal clinic of Raigmore

Hospital and was admitted at the 38th week when mild pre-eclampsia complicated her twin pregnancy. Both foetuses presented by the vertex. Labour commenced spontaneously at the 40th week and the first infant was delivered, face to pubes, after only 90 minutes. The second twin’s cord then prolapsed, tangled with that of the first. It was pulsating vigorously. The first twin’s cord was divided between ligatures and the entangled mass of the cords replaced above the second twin’s head. An easy forceps delivery was then performed and a vigorous infant obtained. The third stage was uneventful.

The placenta was circular in shape, 9 inches (22 cm.) in diameter and weighed 2 pounds 7 ounces (1.23 kg.). The cords were 40 and 44 inches (100 and 110 cm.) in length respec- tively and were twisted together through 8 revolutions. They were both of normal thick- ness and their insertions into the placenta were 2 inches (5 cm.) apart. Numerous anastomoses were present between the vessels on the surface of the placenta. No remnants of an amniotic partition which might have been present between two sacs were present.

The infants weighed 6 pounds 1 ounce (2.9 kg.) and 6 pounds 8 ounces (3.2 kg.) respectively and showed no abnormality. They were breast fed and did well.

This appears to be the first case in the British literature in which both infants survived.

COMMENT This subject was fully reviewed in 1935 by

Quigley, who collected 109 cases, mostly French and German. The most striking feature of his review was the high rate of foetal loss, which was commody due to the cords becoming entangled or knotted and then obstructed. The obstruc- tion usually affects the cord of the second twin as that of the first tightens during its delivery. For this reason it is advised that delivery of the second twin be expedited as soon as the diagno- sis, which is only possible when the first twin has been born, is made. Cases of miscarriage such as reported by Woodburn (1947) and intra- uterine death before labour by BoyIe and Richter (1947) have also been due to twisting of the cords.

Coulton, Hertig and Long (1947), when reporting 2 further cases, discussed the develop- ment of the condition. The amnion forms after the 7th day and formation of the primitive streak commences about the 13th day. They considered it reasonable to assume that the split in the germ disc takes place between these times, division earlier resulting in the usual uni-ovular twins, later in mono-amniotic monsters.

I am grateful to Dr. A. B. Hay for permission to publish the case and to Mr. C. E. L. Hunt for the photograph.

REFERENCES Adamson, -. (1896): Trans. Edinb. obstet. SOC.,

22, 27. Boyle, J. B., and Richter, C. F. (1947): Amer. J .

Obstet. Gynec., 53, 886. Coulton, D., Hertig, A. T., and Long, W. N. (1947):

Amer. J . Obstet. Gynec., 54, 119. Frewer, E. (1936): Brit. med. J., 1, 159. Newman, W. (1858): Edinb. med. J. , 4, 8. Quigley, J. K. (1935): Amer. J . Obstet. Gynec., 29,

Woodburn, A. (1947): Ohio St . med. J.. 43, 631. 354.

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