Subdermal Contraceptive Implants Research Articles

“Free Levonorgestrel Index” (FLI) is a better parameter than plasma level of levonorgestrel for predicting risk of pregnancy during use of subdermal contraceptive implants releasing levonorgestrel

“Free Levonorgestrel Index” (FLI) is a better parameter than plasma level of levonorgestrel for predicting risk of pregnancy during use of subdermal contraceptive implants releasing levonorgestrel

Insertion and Removal of Norplant Contraceptive Implants by Physicians and Nonphysicians in an Indonesian Clinic

This paper reports on a study in which the performances of physicians were compared to those of nonphysician health personnel in inserting and removing NORPLANT subdermal contraceptive implants. The study was conducted in Raden Saleh Clinic at the University of Indonesia, Jakarta, from September 1982 to August 1984. In a group of 828 women who accepted NORPLANT 285 insertions were performed by physicians and 543 by nonphysician health personnel. During the study period, 122 removals were performed (43 by physicians and 79 by nonphysicians). This small proportion of removals reflects the high continuation rate for NORPLANT. There was no significant difference between the two groups of acceptors regarding age, parity, education, or side effects. The average insertion times were 7.6 minutes for the physician group and 7.4 minutes for the nonphysician group (p greater than 0.1). The average removal times were 21.7 minutes for physicians and 21.8 minutes for nonphysicians (p greater than 0.9). Complications during and following insertion and removal were minimal for both groups, and no significant differences were found. It was concluded that nonphysician health personnel are qualified to administer the NORPLANT contraceptive implants.

Ovulation detection following removal of levonorgestrel subdermal contraceptive implants

The time to resumption of ovulation following the discontinuation of levonorgestrel subdermal implants (Norplant R ∗ ∗ Norplant ®: Is the registered trademark of the Population Council's contraceptive subdermal implants. They are manufactured by Huhtamaki Oy/Leiras Pharmaceuticals, Finland, under license from the Population Council. ) was assessed in 10 women. A blood sample (2 ml) was taken at the time of Norplant R removal and then twice weekly until the first evidence of ovulation (serum progesterone concentration ⩾ 5 ng/ml) was documented. Ovulation was resumed in 80% of the cases by 3 weeks and in all the cases by 7 weeks. Prompt return of ovulation following Norplant R removal is an additional advantage of this mode of long-acting contraception.

"Levonorgestrel Concentrations in Maternal and Infant Serum During use of Subdermal Levonorgestrel Contraceptive Implants, Norplant, by Nursing Mothers"

Abstract The transfer of levonorgestrel to infants was studied in 42 lactating women in whom the contraceptive subdermal implants, Norplant®, were inserted 30 to 40 days postpartum. The women breastfed their infants for one year. Simultaneous mother and infant blood samples were taken once during the year. The levonorgestrel serum concentrations were measured by radioimmunoassay. During the fi r st postinsertion month, the levonorgestrel concentration in the infants serum amounted, on the average, to 5% of the maternal concentration. Thereafter, the ratio ranged from 8 to 13%. The implications of this finding are discussed.

Levonorgestrel concentrations in maternal and infant serum during use of subdermal levonorgestrel contraceptive implants, Norplant® by nursing mothers

The transfer of levonorgestrel to infants was studied in 42 lactating women in whom the contraceptive subdermal implants, Norplant®, were inserted 30 to 40 days postpartum. The women breastfed their infants for one year. Simultaneous mother and infant blood samples were taken once during the year. The levonorgestrel serum concentrations were measured by radioimmunoassay. During the fi r ́ st postinsertion month, the levonorgestrel concentration in the infants serum amounted, on the average, to 5% of the maternal concentration. Thereafter, the ratio ranged from 8 to 13%. The implications of this finding are discussed.

Levonorgestrel: recent trials involving subdermal contraceptive implants

Levonorgestrel: recent trials involving subdermal contraceptive implants

Ultrasonic visualization of norplant® subdermal contraceptive devices

This article describes the first use of ultrasound in locating in vivo NORPLANT® subdermal contraceptive implants. Providing low dose, continuous contraception for women, the NORPLANT® system utilizes Silastic tubing filled with levonorgestrel. The progestin-filled tubing is not radiopaque. Anticipating the large scale use of NORPLANT® subdermal implants, the potential, but rare problem of difficult localization of an implant is recognized. The feasibility of using ultrasound for the painless and safe localization of NORPLANT® rods and capsules is demonstrated.

Unaltered lipoprotein and carbohydrate metabolism during treatment with contraceptive subdermal implants containing ST-1435

Nine healthy, fertile women were treated for six months with subdermal contraceptive implants of two different sizes containing a potent progestogen, ST-1435. Lipoprotein cholesterol and triglyceride concentrations were not influenced by the treatment. Similarly, the main apolipoproteins in low- and high-density lipoproteins were not changed, which further supports the interpretation that the lipoprotein metabolism is not affected by this type of treatment. An oral glucose tolerance test (OGTT) including insulin determinations was performed in five of the volunteers with the largest implants. Blood glucose and insulin concentrations during the OGTT remained unchanged during treatment, indicating that the treatment with ST-1435 did not affect carbohydrate metabolism.

Effect of subdermal levonorgestrel contraceptive implants, NORPLANT ®, on liver functions

Forty-seven normal health women were studied longitudinally for changes in liver functions during the use of the levonorgestrel contraceptive implant system, NORPLANT ®. Samples were collected before insertion of the implants and after one, three and six months of use. The enzymes studied were the transaminases (SGOT and SGPT), alkaline phosphatase and -glutamyl transferase. Serum bilirubin and bile acid levels were also measured. The protein synthetic function of the liver was tested by estimation of total proteins, albumin, transferrin, hemopexin, ceruloplasmin and haptoglobin. The three main immunoglobuins, G, M and A, were also measured. There were no significant changes in the liver enzymes after NORPLANT ® use. Serum bilirubin and bile acid concentrations showed rises in the first month of use which ameliorated in subsequent months. Serum albumin was transiently increased during the first and third months. Ceruloplasmin decreased significantly at the sixth month. The concentrations of total serum proteins and the other individual proteins showed no significant change. The results point to safety of NORPLANT ® implant use, as regards hepatic functions.

Effect of subdermal levonorgestrel contraceptive implants, NORPLANT ®, on serum lipids

Forty-seven normal non-smoking parous women were enrolled in a longitudinal study of the effect of use of the subdermal levonorgestrel implants, NORPLANT ®, on serum lipids. Blood samples were collected after an overnight fast before insertion and after three, six, nine and twelve months of use. The high-density lipoprotein cholesterol showed no change until the twelfth month when it was increased (P < .05). Total cholesterol, low-density lipoprotein cholesterol and triglyceride levels decreased significantly during NORPLANT ® use.

Unaltered lipoprotein and carbohydrate metabolism during treatment with contraceptive subdermal implants containing ST-1435.

Nine healthy, fertile women were treated for six months with subdermal contraceptive implants of two different sizes containing a potent progestogen, ST-1435. Lipoprotein cholesterol and triglyceride concentrations were not influenced by the treatment. Similarly, the main apolipoproteins in low- and high-density lipoproteins were not changed, which further supports the interpretation that the lipoprotein metabolism is not affected by this type of treatment. An oral glucose tolerance test (OGTT) including insulin determinations was performed in five of the volunteers with the largest implants. Blood glucose and insulin concentrations during the OGTT remained unchanged during treatment, indicating that the treatment with ST-1435 did not affect carbohydrate metabolism.