title: Effects of antenatal corticosteroids on urinary markers of the initiation of lactation in pregnant women.
abstract: BACKGROUND
  Antenatal corticosteroids are given to most women at risk of preterm delivery, although many do not eventually deliver preterm. Profound disruptions of lactation have been shown in ewes after antenatal corticosteroid treatment, but little is known of the effect on lactation in women. This study aimed to investigate the effects of antenatal corticosteroid treatment on mammary secretion during pregnancy in women.
  
  
  METHODS
  We conducted a prospective cohort study of women receiving betamethasone for anticipated preterm delivery (n = 87). Women collected 24-hour urine samples on days 1, 2, 3, 5, 7, and 14 after treatment if they remained pregnant. We measured urinary excretion of pregnanediol glucuronide (PdG), a major metabolite of progesterone and lactose, which indicates mammary secretion during pregnancy. Withdrawal of progesterone triggers the onset of mammary secretion.
  
  
  RESULTS
  Median (range) gestational age at treatment was 28.8 (23.6-33.6) weeks. A total of 330 24-hour urine samples were collected. Median (range) excretion of PdG was 1.355 (0.139-5.069) mmol/24 hours, and lactose excretion was 0.823 (0.035-6.676) mmol/24 hours. Both PdG and lactose excretion increased with increasing gestational age (P < 0.001). After adjustment for gestational age, there were significant transient increases in lactose excretion (P < 0.001) after betamethasone treatment but no changes in PdG excretion (P = 0.435).
  
  
  CONCLUSIONS
  Antenatal betamethasone treatment was associated with a transient premature secretory activation while women were still pregnant.
authors.affiliation: School of Women's and Infants' Health, The University of Western Australia, King Edward Memorial Hospital, Subiaco, Western Australia, Australia. Jennifer.Henderson@uwa.edu.au
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Henderson
authors.forename: John P
authors.initials: JP
authors.lastname: Newnham
authors.forename: Karen
authors.initials: K
authors.lastname: Simmer
authors.forename: Peter E
authors.initials: PE
authors.lastname: Hartmann
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects / Q000652:urine*; D000328:Adult; D001623:Betamethasone / Q000008:administration & dosage / Q000009:adverse effects / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007774:Lactation / Q000187:drug effects; D007785:Lactose / Q000652:urine*; D042361:Mammary Glands, Human / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy / Q000652:urine*; D011276:Pregnanediol / Q000031:analogs & derivatives / Q000652:urine*; D011295:Prenatal Care; D011446:Prospective Studies
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D001623:Betamethasone; D007785:Lactose; D011276:Pregnanediol