title: At what 'infant-age' can levonorgestrel contraceptives be recommended to nursing mothers?
abstract: OBJECTIVE
  Levonorgestrel (LNG), a low-dose progestin, does not affect lactation but like all drugs taken by breastfeeding mothers, it can be transferred to the infant via breast milk. How infants of various ages cope with this unwanted maternal drug would help in deciding when to recommend this method of contraception to breastfeeding mothers.
  
  
  METHODS
  The study was conducted in 30 exclusively breastfeeding mothers and their 4-, 12- and 24-week-old infants. The mothers daily received 30 micrograms LNG over a five-week period, thus exposing their infants to maternal LNG for that period.
  
  
  RESULTS
  Four-week-old infants could neither absorb nor metabolize LNG efficiently. Twelve-week-old infants could metabolize LNG more efficiently than absorb. Twenty-four-week-old infants could do both efficiently.
  
  
  CONCLUSIONS
  It is safe to introduce LNG to breastfeeding mothers at 12 weeks postpartum.
authors.affiliation: Institute for Research in Reproduction (Indian Council of Medical Research), Parel, Bombay.
authors.forename: S B
authors.initials: SB
authors.lastname: Patel
authors.forename: V S
authors.initials: VS
authors.lastname: Toddywalla
authors.forename: S S
authors.initials: SS
authors.lastname: Betrabet
authors.forename: R D
authors.initials: RD
authors.lastname: Kulkarni
authors.forename: Z M
authors.initials: ZM
authors.lastname: Patel
authors.forename: A C
authors.initials: AC
authors.lastname: Mehta
authors.forename: B N
authors.initials: BN
authors.lastname: Saxena
mesh_terms: D000328:Adult; D000375:Aging; D001942:Breast Feeding; D005260:Female; D006801:Humans; D007223:Infant; D007700:Kinetics; D016912:Levonorgestrel / Q000009:adverse effects* / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D016912:Levonorgestrel