[Possible biological effects of contraceptives] Posibles efectos biologicos de los anticonceptivos.
Possible teratogenic, and ovular and zygotic selection effects of oral and injectable contraceptives were studied in 205 mothers, 52 of whom had used contraceptives only before impregnation and 148 of whom had used them while pregnant, mostly due to failure of the method. The injectables were Depo-Provera, SH 582, Oxogeston, Deladroxate, and Chlormadinone; the orals were Lynestrenol, Chlormadinone, Norgestrel, Retroprogestagen, and Dihydroxyprogesterone. Children born to both groups after taking the contraceptives were examined in terms of sex, birth weight, congenital malformations, and twin frequency. The group that used drugs prior to conception had significantly more twins and more males. For the entire sample, frequency of twins was significantly greater that that of the general population, i.e., 2.5% vs. 1%. Birth weight increased for each group and for the sample as a whole; the most significant difference was found in the group that used contraceptives w hile pregnant. Average birth weight for the population at large was 3123 gm, and of the sample was 3385 gm. Congenital malformations were also shown to have increased from an incidence of 1.5% in the general population to 6.27% in the sample, but those found were not serious. No clear teratogenic effect was encountered. The results are preliminary a nd need more study.