[Post suckling prolactin and estradiol levels as predictors of the time of appearance of the first post partum menstruation].
BACKGROUND
The variability in the duration of lactational amenorrhoea (LA) lead to develop statistical multivariate models to predict the risk of the appearance of the first postpartum menstruation.


OBJECTIVE
To estimate the probability of recovering the first postpartum menstruation by means of a survival analysis, including hormonal levels and other parameters as predictor variables.


METHODS
Eighty one mothers in exclusive breastfeeding until the sixth postpartum month, in whom estradiol, basal and post suckling prolactin were measured at the third post partum month, were studied. The variables that better predict the appearance of the first menstruation between the 3rd and 12th postpartum months, were identified using a Cox model survival analysis.


RESULTS
The median amenorrhea survival time (the lapse when the chance of recovering menstruation is 50%) was 209 days from delivery. Dichotomized estradiol and post suckling prolactin were the only significant variables that predicted the return of menstruation, with cutoff points of 190 pmol/ and 2,550 mIU/L, respectively.


CONCLUSIONS
Post suckling prolantin and estradiol levels, measured at the third post partum month, are predictors for the time of appearance of the first postpartum menstruation.
Valdés
Patricio
P
Departamento de Obstetricia y Ginecología, Facultad de Medicina, Universidad de La Frontera, Chile. pvaldes@ufro.cl
Orellana
Juan J
JJ
D000328:Adult; D000568:Amenorrhea / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001942:Breast Feeding; D004812:Epidemiologic Methods; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D008598:Menstruation / Q000097:blood*; D049590:Postpartum Period / Q000097:blood*; D011388:Prolactin / Q000097:blood*; D013997:Time Factors
D015415:Biomarkers; D004958:Estradiol; D011388:Prolactin