title: The frequency and spectrum of congenital anomalies in natural family planning users in South America: no increase in a case-control study. NFP-ECLAMC Group. Natural Family Planning. Latin-American Collaborative Study of Congenital Malformations.
abstract: Users of natural family planning (NFP) practice periodic abstinence, leading many to reason that such couples should show increased anomalies in offspring as a result of fertilization involving aging gametes. In an effort to complement our NFP cohort study, we currently conducted a case-control study in the same region (South America) in which the largest number of cases have been recruited for our cohort NFP study. During 1992-94, 5324 case-control pairs of mothers were interviewed during the immediate postpartum period in 18 maternity hospitals participating in the Latin-American Collaborative Study of Congenital Malformations: ECLAMC (Spanish acronym for Latin-American Collaborative Study of Congenital Malformations). Natural family planning (NFP) usage was recorded in 6% of mothers in the ECLAMC sample studied (n = 10,648). Overall, no significant differences in frequency of NFP usage were observed between malformed cases (349/5324 = 6.6%) and normal controls (303/5324 = 5.7%) (chi 2 = 3.3; df = 1; p > 0.05). No significant differences in sex ratios were observed between children of NFP user and non-user mothers. Of special interest is the lack of association between NFP and Down syndrome, the sentinel phenotype for the hypothesis of delayed fertilization (aging gametes).
authors.affiliation: ECLAMC at Instituto Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: E E
authors.initials: EE
authors.lastname: Castilla
authors.forename: J S
authors.initials: JS
authors.lastname: Lopez-Camelo
authors.forename: M
authors.initials: M
authors.lastname: da Graça Dutra
authors.forename: J T
authors.initials: JT
authors.lastname: Queenan
authors.forename: J L
authors.initials: JL
authors.lastname: Simpson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D000013:Congenital Abnormalities / Q000453:epidemiology*; D004522:Educational Status; D005193:Family Planning Services; D005260:Female; D006801:Humans; D008297:Male; D008423:Maternal Age; D012252:Natural Family Planning Methods; D010298:Parity; D011247:Pregnancy; D012744:Sex Ratio; D013020:South America