Embryonic abnormalities at medical termination of pregnancy with mifepristone and misoprostol during first trimester: observational studyBMJ 1998; 316 doi: https://doi.org/10.1136/bmj.316.7146.1712 (Published 06 June 1998) Cite this as: BMJ 1998;316:1712
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I have serious doubts about the validity of the data in the report of embryonic abnormalities at medical terminations of pregnancy (1). My own experience is that embryos are delicate and can be readily disrupted even during careful handling. Although the authors state that "strict criteria were used to distinguish structural abnormalities from traumatic damage" they give no details of these criteria and whether they have been generally accepted as distinguishing between trauma and abnormality in delicate embryonic tissue. I believe it is important to specify in how many cases traumatic damage was seen.
Although the authors state that macroscopically abnormal embryos were further examined histologically, they do not report the histological findings and it is surprising that no pathologist was included as an author. Were all the neural tube and abdominal wall defects confirmed histologically? It is easy to envisage how compression of a delicate embryo during delivery might induce artefactual rupture of both the abdomen and central nervous system.
A 23% anembryonic pregnancy rate (48 in 206 cases) before 9 weeks of pregnancy is very high when compared with the 16% found is a study of 38 abnormal early pregnancies(2) and the 1% rate found in an ultrasound study of 17,820 normal (albeit 10-13 week) pregnancies (3). Such a discrepancy must be explained.
I believe that the unexpected finding of a 34% non-viable pregnancy rate can be explained by misinterpretation of macroscopic appearances.
1. Blanch G, Quenby S, Ballantyne ES, Gosden CM, Neilson JP Holland K. Embryonic abnormalities at medical termination of pregnancy with mifepristone and misoprostol during first trimester: observational study. BMJ. 1998;316:1712-3.
2. Alcazar JL. Laparte C. Lopez-Garcia G. Corpus luteum blood flow in abnormal early pregnancy. J Ultrasound Med. 1996;15:645-9.
3. Pandya PP. Snijders RJ. Psara N. Hilbert L. Nicolaides KH. The prevalence of non-viable pregnancy at 10-13 weeks of gestation. Ultrasound Obstet Gynecol. 1996;7:170-3.
Competing interests: No competing interests