Ectopic pregnancy and myoma uteri: teratogenic effects and maternal characteristics.

Morphological data from 3,614 well-preserved human embryos derived from artificial termination of pregnancy were used to determine whether ectopic implantation or enlarged myomas could enhance the prevalence of localized malformations of the embryo. The frequency of malformed embryos was 11.6% among 43 recovered from ectopic pregnancies, 6.2% among 97 from myomatous pregnancies, and 3.3% among 3,474 from normally implanted pregnancies not complicated by myomas. Unilateral amelia in the ectopic cases and caudal dysplasia in the myoma cases were significantly increased. Both malformations were quite unusual in the control group. It is argued that spatial restrictions could be a teratogenic agent in human embryos. Mothers of both ectopic and myoma cases were on average much older than mothers of the control specimens, and those with myomas had a higher frequency of previous pregnancy wastages. Ectopic pregnancy was found to be associated with lowered parity, previous ectopic pregnancy, and maternal smoking and drinking. These associations are discussed and interpreted in relation to etiology of each of the two conditions.