Neural tube defects and first trimester operations.

Swedish health care registries were used to identify women who had surgery during pregnancy and their offspring. Among the 2,252 infants born to women who had first trimester operations during 1973-1981, six had definite diagnoses of neural tube defects (expected number, 2.5). Scrutiny of the records showed that 572 operations occurred during gestational weeks 4-5, the period of neural tube formation, and that the mothers of five of the six infants with neural tube defects had an operation during that period (expected number of neural tube defects, 0.6) although one of the offspring probably had Meckel's syndrome. The relationship between neural tube defects and operation during pregnancy is discussed including the possibility that the association may be random.