Effects of levonorgestrel implant upon TSH and LH levels in male infants during lactation.

OBJECTIVES: The objective of the study is to evaluate the effects of levonorgestrel transferred through breast milk on thyroid stimulating hormone (TSH) and luteinizing hormone (LH) levels in full breast-fed infants. METHODS: Forty healthy postpartum women and their male newborns were recruited for the study. Women were randomly allocated to two study groups: Group 1, IUD users and group 2, Norplant users. Blood and milk samples were collected on the day of IUD or Norplant insertion and 3 and 6 months later for TSH and levonorgestrel measurements. RESULTS: The results disclosed a significant decrease in TSH levels, and a negative relationship between LNG levels and TSH concentration in breast feeding infants at 3 months after implant insertion. The lowest TSH levels were observed at 6 months in the women from group 2. CONCLUSIONS: The overall data indicate that the LNG levels transferred to fully breast-fed infants through breast milk from Norplant users significantly modified their TSH levels.

Effects of low steroid doses administered in the mid and late follicular phase on the LH surge, ovarian steroids and follicular maturation in eumenorrheic women.

The effects of four low doses of synthetic steroids, administered orally and starting on day 8 (group I) or on day 10 of the menstrual cycle (group II), upon LH surge, ovarian steroidogenesis, follicular maturation and menstrual cycles were studied in 10 eumenorrheic women. The results revealed that the day before the LH surge, the highest level of estrone-3-glucuronide was observed in both groups. Twenty-four hours after the last dose, the maximum urinary LH levels were recorded in groups I (day 11), and II (day 13). Pregnanediol-3 alpha glucuronide remained low during the study in group I, whereas in group II a gradual rise of this hormone starting on day 13 was registered and the highest level was found at day 21 of the menstrual cycle. Follicular maturation and ovulation were observed only in women from group II. Short and normal length cycles were recorded in groups I and II, respectively. In summary, low doses of exogenous synthetic steroids administered on day 8, but not on day 10 of the cycle, inhibit follicular maturation and ovulation.

Luteinizing hormone releasing hormone agonist for postpartum contraception.

OBJECTIVE: To compare the effects of a GnRH agonist upon ovarian function, bleeding pattern, and nursing practice in two groups of Mexican women during the postpartum period. DESIGN AND PATIENTS: Two doses of a GnRH agonist (300-600 micrograms) were investigated during the postpartum period in fully breastfeeding mothers at 6 weeks postpartum. A total of 29 women who desired to breast feed for at least 6 months were allocated in three study groups; group I (control); group II, taking 300 micrograms; and group III, taking 600 micrograms. RESULTS: After treatment initiation, an increase of estrone levels was observed among treated women; thereafter, irregular fluctuations of estrone levels were observed, mainly among women from group III. All the control women and two participants from group III ovulated during the study. Moderate bleeding was registered in most of the women from group I, while amenorrhea and spotting were observed in participants from groups II and III, respectively. There was no significant effect of the treatment on nursing practice between groups. CONCLUSION: GnRH agonists have advantages over steroids for hormonal contraception during the postpartum period in breastfeeding women. Symptoms of hypoestrogenism were not reported any time in either the controls or the treated groups, as estrone levels were not suppressed to menopausal values. Once-daily administration of GnRH agonist could be a reliable, acceptable and safe contraceptive method during the postpartum period in breastfeeding women. More information is required to establish GnRH analog contraceptive efficacy.