Abstract
The pattern of luteinizing hormone (LH) pulsatile release and the mean concentrations of follicle-stimulating hormone, oestradiol and progesterone were studied in nursing and non-nursing women. Blood samples were drawn at 5 min intervals between 10: 00 and 14: 00 h and between 22: 00 and 02: 00 h at months 3-4, 5-6, 7-8 and 9-10 post-partum in nursing women and in the follicular phase in non-nursing women. In nursing women, mean LH concentrations at months 3-4 were significantly lower than in non-nursing cycling women only in the subgroup which subsequently experienced >6 months of lactational amenorrhoea, although all were fully nursing with a similar suckling frequency. LH pulses in plasma were found at all times in nursing women. There were no significant differences in the frequency (about four pulses every 4 h), amplitude or duration of LH pulses related to the duration of amenorrhoea, nor did these parameters vary significantly between amenorrhoeic or cycling nursing women and non-nursing women. Nursing amenorrhoeic women exhibited a normal frequency of LH pulse well in advance of the resumption of the first post-partum menses, suggesting that mechanisms other than the suppression of the gonadotrophin-releasing hormone pulse generator intervened in the inhibition of ovarian function during lactation.
| Original language | English |
|---|---|
| Pages (from-to) | 1957-1961 |
| Number of pages | 5 |
| Journal | Human Reproduction |
| Volume | 10 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 1 Jan 1995 |
Keywords
- Breastfeeding
- Lactational amenorrhoea
- Luteinizing hormone pulses
- Post-partum
ASJC Scopus subject areas
- Reproductive Medicine
- Rehabilitation
- Obstetrics and Gynaecology