Matti Heikkilä

Levonorgestrel in milk and plasma of breast-feeding women with a levonorgestrel-releasing IUD

A levonorgestrel-releasing intrauterine contraceptive device was used by 10 breast-feeding women beginning 6 weeks after delivery. Two models of IUD were used. One released 10 microgram (5 patients), the other 30 microgram (5 patients) of levonorgestrel per day. Plasma and milk samples were collected 8 times over a 3-month period and the concentrations of levonorgestrel determined by radioimmunoassay. An improved and sensitive method for the determination of levonorgestrel in milk was developed. A column chromatographic purification of a milk extract before radioimmunoassay made possible the use of large milk samples in order to improve the sensitivity. The plasma concentrations during the follow-up period were 207 +/- 64 pg/ml (mean + SD) in the 10 microgram and 235 +/- 87 pg/ml in the 30 microgram/day releasing IUD groups. The milk levonorgestrel concentrations were 56 +/- 35 and 57 +/- 34 pg/ml, respectively. The plasma to milk ratio of levonorgestrel was initially 100:15 and at the end of the 3-month follow-up period 100:25. There were no significant differences in the milk and plasma concentrations between the study groups. The total amount of levonorgestrel excreted per day in 600 ml breast milk is approximately 0.1 per cent of a daily dose of 30 microgram.

Duration of breast-feeding and development of children after insertion of a levonorgestrel-releasing intrauterine contraceptive device

IUDs releasing levonorgestrel, 10 micrograms per day (30 patients) and 30 micrograms per day (40 patients), and copper-releasing IUDs (Nova-T) (40 patients) were inserted six weeks after delivery in 110 breast-feeding amenorrheic women. The infants were carefully followed-up by recording monthly weight gain and growth, age of eruption of the first tooth, age of being able to walk without support and morbidity to infective diseases. No differences were noticed between the study groups. Plasma samples were collected from 13 children at the age of eight months, while the mothers were breast-feeding. Six mothers had a levonorgestrel-releasing IUD and seven others the Nova-T or no hormonal or intrauterine contraceptive. No differences were noticed between the groups in Na, K, Cl, Ca, P, protein, albumin, creatinine, urate, Fe, cholesterol, triglyceride, bilirubin, alkaline phosphatase, aspargine aminotransferase, alanine aminotransferase, lactate-dehydrogenase or high density lipoprotein cholesterol serum concentrations in the children. The duration of breast-feeding and initiation of supplementary feeding was recorded. The continuation of breast-feeding 75 days after the insertion of a 30-micrograms per day levonorgestrel-releasing IUD was 56 percent while in the Nova-T group only 21 percent had discontinued which is a statistically significant difference (p less than 0.05); later the difference disappeared. Compared with the lactation time of their previous breast-feeding reported by women in both groups, the present lactation time increased by ten weeks. The infants received substitute foods including substitute milk, juices, etc., in the Nova-T group at 3.9 months and in the levonorgestrel-releasing IUD group at 3.4 months after delivery.

Body iron stores and patterns of bleeding after insertion of a levonorgestrel- or a copper-releasing intrauterine contraceptive device

The effects of the use of a copper-releasing IUD (Nova-T) and a levonorgestrel-releasing IUD on iron stores were studied over the 1st year after postmenstrual insertion and during lactation after childbirth. The pattern of bleeding was evaluated daily over the 1st year. Conventional hematological evaluations and serum ferritin concentrations were measured in 15 women in each group at the time of insertion and 6 and 12 months later. After postmenstrual insertion there was a significant increase at 1 year in the number of red blood cells in the levonorgestrel-releasing IUD group and an increase in the mean serum ferritin concentration that was not significant. In the copper-releasing IUD group a significant (P<0.025) decrease was found in serum ferritin concentrations after 6 and 12 months and a statistically significant difference existed between serum ferritin concentrations of the copper-releasing IUD group and the levonorgestrel-releasing IUD group at 1 year (P<0.02). When the IUDs were inserted puerperally there was a significant rise in the number of red blood cells and decreases in the mean corpuscular volume and mean corpuscular hemoglobin at 1 year in both groups. The mean serum ferritin concentration decreased during the 1st 6 months in both groups but in the levonorgestrel-releasing IUD group it reached a plateau and in the copper-releasing IUD group it continued to decrease. At 1 year there was a significant difference in the mean serum ferritin concentrations between the 2 IUD groups (P<0.005). The different effects of these 2 IUDs on body iron balance are based on differences in the patterns of bleeding in the women using the IUDs. Over the 1st 3 months of postmenstrual insertion the number of days of bleeding and spotting was higher in the levonorgestrel-releasing IUD group than in the copper-releasing group but during the latter 1/2 of the year there were fewer days of bleeding and spotting in women using the levonorgestrel-IUD than in women using the copper-releasing IUD. The insertion of a levonorgestrel-releasing IUD during lactational amenorrhea was associated with more days of bleeding and spotting during the 1st 3 months than the insertion of a copper-releasing IUD. Most of this was scanty spotting and after the 1st month the women using levonorgestrel-IUDs had fewer days of menses-like bleeding than the women using a copper-releasing IUD. The results of the study show that the longterm effects of IUDs on iron stores may be precisely evaluated by using serum ferritin determinations. The copper-releasing IUD which results in a minimal increase in the amount of bleeding over the 1st year still affects the serum ferritin concentration whereas the levonorgestrel-releasing IUD is associated with a decreased amount of bleeding and prevents consumption of the body iron stores. (authors)

Puerperal insertion of a copper-releasing and a levonorgestrel-releasing intrauterine contraceptive device.

A copper-releasing IUD and levonorgestrel-releasing IUDs releasing 30 micrograms and 10 micrograms levonorgestrel per day were inserted six weeks after delivery in 110 volunteers. During the treatment, events and patterns of bleeding were recorded and plasma levonorgestrel concentrations were measured. The number of events in one year of follow-up was very low, four removals out of 40 in the copper-releasing IUD group and five removals out of 70 in the levonorgestrel-releasing IUD group. Bleeding and spotting was significantly more common after insertion of a levonorgestrel-releasing IUD than a copper-releasing IUD, but it was scanty and well-tolerated. After three months, levonorgestrel-releasing IUD patients had less bleeding and spotting than the copper-releasing IUD patients. No pregnancies occurred during the study period. There were two uterine perforations with a uterine sound at the insertion. In the 30-micrograms per day levonorgestrel-releasing IUD group, initially high plasma levonorgestrel concentrations reached a plateau four weeks after the insertion. In the 10-micrograms per day levonorgestrel-releasing IUD group, the plasma concentrations of levonorgestrel stabilized after the initial two weeks.

Immediate postabortal insertion of a levonorgestrel-releasing IUD

Experimental IUDs releasing only 10 μg levonorgestrel per day and established copper-releasing IUDs (Nova-T) were inserted in 60 women in connection with legal first-trimester abortion. Bleeding and spotting and other events were recorded during the first year. Restoration of the menstrual cycle was studied. Blood samples were collected twice a week over a three-month period from five women receiving a levonorgestrel-releasing IUD to determine plasma levels of estradiol, progesterone, levonorgestrel, LH and FSH. FSH showed an increase approximately ten days (range 4–19) after abortion. LH/hCG concentrations reached a plateau approximately 24 days (range 9–42) after abortion. Initially, levonorgestrel concentrations were two-fold compared with concentrations of 90 pg/ml after four weeks. After four weeks the plasma levonorgestrel concentrations were stable. All five women had an ovulatory menstrual cycle. The first periods occurred 35 days after operation in the levonorgestrel-IUD group and 30 days after operation in the Nova-T group. The median duration of bleeding and spotting after the insertion was 12 days (range 3–26) in the Nova-T group and 12.5 days (range 3–93) in the levonorgestrel-IUD group. The difference was not statistically significant. From the second month on, menses-like bleeding was more common in the copper-releasing IUD group than in the levonorgestrel-IUD group. The difference was statistically significant (p < 0.001). After one year 75 percent of the patients continued with their IUDs in both groups. One pregnancy occurred in the experimental levonorgestrel-IUD group. One total expulsion was noticed in both groups, and one partial expulsion in the levonorgestrel-IUD group. Two levonorgestrel-IUDs and four Nova-Ts were removed because of bleeding and/or pain. One infection was noticed in the whole group six days after the operation. In the levonorgestrel-IUD group 74 percent of the women had a regular cycle after one year, while all Nova-T patients had a regular cycle. Twelve percent (7 women) were lost to follow-up at one year. The results of this study suggest that a levonorgestrel-releasing IUD can be inserted after legal first-trimester abortion and the results are comparable with those of previous studies that have been made using copper-releasing IUDs.

Effect of day length and natural versus incandescent light on perching and the diurnal rhythm of feeding behaviour in layer chicks (Gallus g. domesticus)

Abstract Not much is known about the effect of light sources on behavioural development of laying hens. The effect of natural and artificial light, respectively, on feeding and perching of layers was studied. 126-day-old chicks were divided into 1) A8: 8h artificial light+16h darkness, 2) A16: 16h artificial light+8h darkness, 3) N8: 8h daylight+16h darkness. A8 and N8 birds did not differ in their feeding behaviour, whereas the mean proportion of A16 birds feeding was 0.056 lower than in A8 birds in daytime (P<0.001) and 0.019 lower in nighttime (P<0.0001). N8 birds tended to start nighttime perching earlier than A8 birds (hazard ratio=8.5; P=0.056). These results suggest that chicks can change their feeding behaviour depending on day length. Natural daylight was found to precipitate the onset of nighttime perching in the life of the pullet.