Effect of IUDs on uterine cyclic AMP rabbits.

IUDs were inserted into the uteri of 15 New Zealand White rabbits in order to observe the effect of IUDs on uterine cyclic AMP. Rabbits received either a plastic IUD, a plastic-copper IUD, or were untreated. After 1, 2, or 3 months, the uteri were removed and analyzed. In 3 animals, IUDs were removed after 2 months and uteri excised 1 month later. Cyclic AMP was measured in neutralized, acid-extracted supernatants by the radioimmunoassay procedure of Steiner et al. Cyclic AMP was significantly lower (p less than .04) in the uteri containing plastic or plastic-copper IUDs by 1 month and remained depressed for up to 3 months. Cyclic AMP levels returned to control values in animals in which the plastic IUD was removed at 2 months, but remained depressed after removal of the plastic-copper IUD. The delayed effect of Copper-containing IUDs on the return of fertility in the rabbit needs further study.     

Contraception with intrauterine devices

A review of the history of contraception with intrauterine devices, characteristics of present devices, and directions of current research is presented. The serious need for population control is not yet being met by today's inconvenient, ineffective, or unsafe methods. Intrauterine devices have been best for international family planning programs because they are cheap, easily installed, and provide continuous protection. There are many different models that have been and are being used, with different effectiveness and complication rates. The most commonly used today is the Lippes Loop, with a pregnancy rate of 2.8/100 years of woman use and an expulsion rate of 10.4. Most of these failures occur in the first few months of use, after which these rates are greatly reduced. The removal rate because of bleeding or pain for the Lippes device is 14.0. Other devices commonly used have pregnancy rates ranging 1.3-4.7, expulsion rates of 2.6-25.8, and removal rates of 13.5-22.1. Expulsion is directly related to the size and design of the IUD and the age and parity of t,e recipient. It is important to match the size of the device used to the individual characteristics of the patient. Research is seeking a design that will implant itself in the endometrium to resist expulsion, but not too deeply so that it is covered. Removal for bleeding and pain remains the most frequent complication of the IUD, and it partly depends on the skill of the inserting physician and how well the patient is psychologically prepared for side effects in the first months of use. Pregnancy is the most significant IUD complication. The key to an effective IUD is an understanding of its antifertility mechanism, which has thus far eluded researchers. The IUD prevents implantation of the blastocyst in the uterine wall, which may be due to a foreign-body reaction in the endometrium. IUDs with copper cause a greater reaction than plastic devices and provide hope for a very effective device; particularly the T-shaped design, which resists expulsion. The most promising new IUD is the Dalkon Shield. It has small projections that imbed in the endometrium and a broad surface for contact with the uterine wall. In preliminary experiments the pregnancy rate with this device was 1.1, the expulsion rate 2.3, and the removal rate 2.0, much lower than that with any other device yet developed. It is concluded that IUDs such as the Dalkon Shield can provide safe contraception with high effectiveness.     

Effect of an intrauterine contraceptive on the state of fertilized ova in rats

47 pubescent rats were inserted with IUDs and then impregnated. Ova were removed at 2, 3, 4, 5, and 6 days after impregnation and examined microscopically. The IUD failed to interrupt the processes of fertilization and of cleavage of the ova during their passage along the oviduct or the rate of passage. When a blastocyst entered the uterine cornu with an IUD, degenerative changes appeared leading to its death be fore the development of decidual transformations in the endometrial stroma.     

Effects of clomiphene citrate on early pregnancy in guinea-pigs

Clomiphene citrate (2 mg/kg body wt) given on the day of mating can block or interrupt pregnancy in guinea-pigs. Corpus luteum function, uterine histology, implantation and embryo development were studied in clomiphene-treated and control animals on Days 5, 9 and 20 of pregnancy. Following treatment, only 25% of the females were regularly pregnant, presenting large and healthy foetuses. The other females examined showed either pregnancy with embryos undergoing resorption or no sign of pregnancy. In these females, corpus luteum size was reduced, progesterone concentrations were very low and the endometrial glands and the epithelium were often altered. It is concluded that clomiphene causes a reduction in fertility by altering the uterus and, by directly or indirectly inducing luteolysis, causes later pregnancy loss.     

In support of a compensation plan for vaccine-associated injuries. Infectious Diseases and Immunization Committee,Canadian Paediatric Society.

Between 1971 and 1973, 200 Dalkon Shield and 142 Gyne-T 200 intrauterine devices (IUDs) were inserted at the department of obstetrics and gynecology in a large urban hospital. In 1984 retrospective analysis of events associated with the use of these IUDs was done. Hospital and clinic charts were reviewed, and the women were contacted to obtain information on infertility and the outcome of pregnancy after discontinuation of IUD use. The rates of events leading to discontinuation of IUD use 2 years after insertion were similar in the two groups except for that of planned pregnancy, which was higher in the Dalkon Shield users (p less than 0.05). The rates of accidental pregnancy per 100 women were 3.8 for the Dalkon Shield users and 1 for the Gyne-T 200 users. The rates of pelvic inflammatory disease (PID) based on all cases of PID and follow-up information were similar in the two groups. There were no differences between the two groups in outcome of pregnancy with the IUD in situ or after expulsion or removal of the IUD because of planned pregnancy or other reasons. Infertility rates after discontinuation of IUD use were similar for the Dalkon Shield and Gyne-T 200 users. The results confirm the authors'' opinion that the Dalkon Shield and Gyne-T 200 IUDs are safe and effective methods of intrauterine contraception.     

Inhibition of DNA synthesis in isolated human endometrial cells by a levonorgestrel-releasing intrauterine device

OBJECTIVE: To estimate the effect of an intrauterine device (IUD) releasing 20 micrograms levonorgestrel (LNG) per 24 hours on DNA synthesis in human endometrial cells before and after 12 months of use. STUDY DESIGN: Endometrial specimens were collected from the anterior or posterior wall of the miduterus from 6 females on cycle day 10-12 before insertion of the IUD and after 12 months of use. RESULTS: Previous results from our group did not reveal any influence on endometrial DNA cell content when a levonorgestrel IUD releasing 2 micrograms/24 h was used for 12 months in a group of fertile females. In this study, the IUD release rate, 20 micrograms LNG/24 h, was statistically significantly different from the results in the previous studies. The effect of the levonorgestrel IUD on endometrial proliferation was dose dependent, and a significant correlation could be found between continuous exposure to LNG and inhibition of DNA synthesis in endometrial cells. CONCLUSION: Inhibition of proliferative activity in endometrial cells seems to be reflected by a decrease in DNA synthesis per cell nucleus and contributes to the clinical performance of the LNG-releasing IUD.     

Contraceptive efficacy of a novel intrauterine device (IUD) in white-tailed deer

Overabundant white-tailed deer (Odocoileus virginianus) pose risks to property, health, and safety of human beings. Public concerns about lethal management can impair efforts to address these issues, particularly in urban settings. Several techniques developed for reducing reproductive output of deer have limited utility because they require repeated dosing to achieve permanent effect and face uncertain regulatory approval for use beyond experimentation. From 10 August 2006 through 30 December 2007, we evaluated the contraceptive efficacy of copper-containing intrauterine devices (IUDs) implanted trans-cervically in white-tailed deer at the E.S. George Reserve in Pinckney, Michigan. Intrauterine devices were implanted before (n = 9) and shortly after (n = 10) the breeding season. Post-breeding season IUD treatment was in conjunction with a 5 cm³ dose of 5 mg/ml prostaglandin F_2α (PGF_2α), delivered subcutaneously. Intrauterine devices reduced pregnancy rates when administered prior to breeding (P < 0.001) and prevented pregnancy for up to 2 years (the duration of the study). Two of 8 does that received IUDs prior to the breeding season and survived to the end of the study became pregnant (due to loss of the implant) during the second year while all (n = 16) does without implants conceived. Cervical changes associated with early pregnancy made trans-cervical implantation after the breeding season challenging, and resulted in improperly placed IUDs in 2 treated does. The apparent expulsion of IUDs by pregnant does that received the combined treatment after breeding suggests IUD treatment should be limited to the pre-breeding season. Intrauterine devices show potential as a tool for small-scale deer population management via non-steroidal reproductive inhibition.     

The copper-7 intrauterine contraceptive device: 5-year evaluation.

Over a 5-year period a family practitioner inserted copper-7 (Cu-7 intrauterine contraceptive devices (IUDs) in 134 women. The rates of continued use after 2 years, 53.0% for the women''s first IUD and 63.9% for all their IUDs, and of accidental pregnancy, 2.4%, are comparable to those in the literature. However, in this series the rate of expulsion was 0.8%, much lower than that in the literature. Fertility did not appear to be reduced in women who planned to have pregnancies after the device was removed. A carefully scrutinized technique of insertion and conscientious follow-up make the Cu-7 IUD an acceptable form of contraception for many patients in a family practice.     

Fertility control using intrauterine devices: an alternative for population control in wild horses

The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 nontreated mares and a fertile stallion in a large pasture until October 20 (112 d). None of the IUD-treated mares and all the nontreated mares became pregnant. The IUD-treated mares were maintained separately from the stallion during the winter. Following removal of the IUD on April 27 of Year 2, the mares were again introduced to the pasture with the stallion together with 6 nontreated mares. For the 6 mares previously treated with an IUD, the mean interval from introduction to the stallion to conception was 17.5 +/- 5 d or 1.3 cycles per pregnancy, and all mares produced a normal foal at term. Subsequently, 19 recorded mare breeding seasons resulted in 18 foals. Uterine cytology and histopathology indicate that the IUD causes mild chronic endometritis without permanent changes in the endometrium. We conclude that based on our observations, the O-ring-shaped IUD is an effective, safe and practical contraceptive method for mares.     

Breeding territory fidelity in a partial migrant, the American dipper Cinclus mexicanus

American dipper Cinclus mexicanus populations are frequently composed of resident individuals that occupy permanent territories year round and migratory individuals that overwinter with residents but migrate to breeding territories on higher elevation creeks each spring. Between 1999 and 2004 we examined how migratory strategy (resident/migratory) and sex differences influence breeding territory fidelity of American dippers occupying the Chilliwack River watershed, British Columbia, Canada. Counter to expectation we found that the migratory strategy of American dippers did not influence whether birds breeding in one year were found on their former breeding territory in the next. Migratory strategy also did not affect the probability that known surviving dippers occupied the same breeding territory in the following year. Males and females were equally likely to be found on their former territory in the following year (females 43%, males 41%) and known survivors had similar levels of breeding territory fidelity (females 74%, males 68%). However, breeding territory fidelity of males and females varied in response to different factors. Surviving female dippers were more likely to be found on their former breeding territory in the subsequent year following a successful breeding attempt than an unsuccessful breeding attempt. Prior reproductive performance did not influence whether surviving male dippers were found on their former breeding territory. Male dippers were more likely to be found on their former territory and, if they survived, have higher breeding territory fidelity when their mate also returned to that same territory. Mate retention also influenced whether females were found on their former territory in the following year but had no effect on the breeding territory fidelity of known survivors. We argue that sex‐specific dispersal decision rules in American dippers are driven by sex differences in the predictability of breeding performance between years and sex differences in how mate retention influences subsequent reproductive success.     

Mechanisms behind intrauterine device-induced luteal persistence in mares

Intrauterine glass balls are used to prevent oestrous signs in sports mares, but the mechanism of action is unknown. It has been suggested that the glass ball can mimic an embryo or act via an induced chronic uterine inflammation and absent or continuous low-grade prostaglandin (PG) release. The purpose of this study was to induce prolonged luteal function in mares using a small intrauterine device (IUD) and to study the mechanisms behind prolonged IUD-induced luteal function. A uterine swab and a biopsy specimen were obtained in early oestrus. A water-filled plastic ball, diameter 20mm and weight 3.6g, was inserted into the uterus 2-4 days after ovulation; the control mares underwent similar cervical manipulation without ball insertion. The mares were examined three times per week until day 23 and twice weekly thereafter until they returned to oestrus (transrectal palpation, ultrasonography and progesterone determination). The location of the IUD was recorded and ultrasound scans were video-recorded to assess the frequency of uterine contractions. When the mare returned to oestrus, a uterine swab and biopsy specimen were obtained and the bacteriological, cytological and histological (inflammation and glandular dilation) results compared with the samples obtained before the IUD insertion. The PG F(2alpha) metabolite levels were measured in the plasma of four control mares and eight IUD mares on days 11-16. The IUD induced a prolonged luteal phase in 75% of the mares (9/12; IUD-P); the mean dioestrous length was 57.0 days. The three mares that did not respond to the IUD (IUD-N) showed a mean dioestrous length of 15.7 days and the 12 control mares 16.1 days. The inflammation and glandular dilation scores were not significantly different in pre- and post-manipulation biopsy specimens. Although locational changes of the IUD were observed, they occurred over very small distances and were mostly limited within the body-bifurcation area. The IUD-N and control mares showed increased uterine contractility 11-16 days post-ovulation, whereas the IUD-P mares did not. The control mares (n=4) and IUD-N mares (n=2) showed increased PG levels from day 14 post-ovulation, while the IUD-P mares (n=6) showed basal levels only. We concluded that the IUD did not cause continuous PG release and suggest that close contact of the IUD with the endometrium may prevent the endometrial cells from releasing PGF(2alpha).     

Surgical correction of genital prolapse in three rhesus monkeys

Three adult female rhesus monkeys (Macaca mulatta) in a breeding colony of approximately 75 adult females developed a clinical condition characterized by protrusion of the cervix through the vulva during pregnancy and/or following parturition. The Gilliam round-ligament uterine ventro-suspension procedure (hereafter called the Gilliam uterine suspension or uterine suspension procedure) was used to return the cervix to a normal anatomical position. Following the procedure, one female delivered a normal live infant, but reprolapsed. After a second suspension procedure, she again became pregnant and delivered a normal live infant without a reoccurrence of the prolapse. A second animal never became pregnant despite repeated breedings to different males for two years. The third animal became pregnant twice following the procedure. The first pregnancy terminated in abortion at two months of gestation, while the second pregnancy ended in an apparent dystocia, necessitating a cesarean section and delivery of a dead fetus. The animal died post-operatively. This surgical procedure successfully salvaged one of these animals which otherwise had no reproductive future.     

Hyaluronidase activity of human endometrial tissues & uterine fluids.

Hyaluronidase activity of human endometrial tissues and uterine fluids was investigated. Endometrial tissue and uterine fluid specimens were obtained from normal human subjects, and different cases of uterine dysfunction induced by steroidal contraceptives, copper IUD, lactational amenorrhea, and in early pregnancy. Hyaluronidase activity was found to increase from Cycle Days 8 to 10 and reach the maximum value during the secretory phase. Hyaluronidase activity was reduced in both endometrial tissue and uterine fluid during lactational amenorrhea and early pregnancy, and was drastically reduced in copper-IUD and steroidal contraceptive users. The low hyaluronidase activity in the early phase of the cycle may be due to rapid growth of endometrial tissue. In the secretory phase, the corresponding activities were found to increase because of high secretory activity and enhanced catabolic processes. In early pregnancy, the low lysosomal enzyme activity may also be explained on the basis of increased endometrium tissue growth. Low hyaluronidase activity of amenorrhic subjects may be due to the absence of ovarian steroids.     

Reconnaissance for future breeding sites by spotted sandpipers

We studied the sex-role-reversed, polyandrous spotted sandpiper(Actitis macularia) from 1974 to 1990 in northern Minnesota,USA. After peak arrival of breeding birds and before peak departureat the end of the breeding season, there were many short-termvisitors (transients) to the study site. Stepwise discriminantfunction analysis (DFA) was used to determine the importanceof absolute sex ratio (males/female), sex of the transient bird,number of nests, and number of breeding males and females duringthe week of visit in predicting whether a visiting bird wouldreturn the following year. In addition, multiple regressionwas used to determine how much variability in the number oftransient birds returning in subsequent yearscould be explainedby annual values during the year of transience for numbers ofbreeding males and females, numbers of eggs laid and hatched,and absolute sex ratio. Annual recruitment of foreign adultsranged from 1 to 20 birds, of which 0–56% were seen visitingin previous years. Female recruits were more likely than malesto have been observed previously as transients. Twenty-two chickshatched at our study site returned and bred for the first timemore than 1 year after hatching. Of these, 9 (41%) were seenas transients between the year of hatch and breeding. The DFAshowed that transient females returned more often than transientmales and that the number of transients returning in subsequentyears was positively associated with the absolute sex ratioduring the week visited. When the sexes were analyzed separately,none of the weekly variables significantly discriminated femalereturn, but sex ratio was positively associated with male return.Regression showed that the number of transient birds returningin subsequent years was positively associated with the numberof male breeders at our study site during the year a bird visited.Percentage return the year after transience was positively associatedwith the number of eggs laid at our study site during the yeara bird visited. When sexes were analyzed separately, the higherthe number of female breeders during the year a bird visited,the greater the number of males returning in subsequent years,and greater numbers of breeding males were positively associatedwith transient female return. Based on our results, we suggestthat transient birds were searching for better breeding areasfor future breeding and that intrasexual competition made thisinformation more important to females than to males.     

Testing VHF/GPS Collar Design and Safety in the Study of Free-Roaming Horses

Effective and safe monitoring techniques are needed by U.S. land managers to understand free-roaming horse behavior and habitat use and to aid in making informed management decisions. Global positioning system (GPS) and very high frequency (VHF) radio collars can be used to provide high spatial and temporal resolution information for detecting free-roaming horse movement. GPS and VHF collars are a common tool used in wildlife management, but have rarely been used for free-roaming horse research and monitoring in the United States. The purpose of this study was to evaluate the design, safety, and detachment device on GPS/VHF collars used to collect free-roaming horse location and movement data. Between 2009 and 2010, 28 domestic and feral horses were marked with commercial and custom designed VHF/GPS collars. Individual horses were evaluated for damage caused by the collar placement, and following initial observations, collar design was modified to reduce the potential for injury. After collar modifications, which included the addition of collar length adjustments to both sides of the collar allowing for better alignment of collar and neck shapes, adding foam padding to the custom collars to replicate the commercial collar foam padding, and repositioning the detachment device to reduce wear along the jowl, we observed little to no evidence of collar wear on horses. Neither custom-built nor commercial collars caused injury to study horses, however, most of the custom-built collars failed to collect data. During the evaluation of collar detachment devices, we had an 89% success rate of collar devices detaching correctly. This study showed that free-roaming horses can be safely marked with GPS and/or VHF collars with minimal risk of injury, and that these collars can be a useful tool for monitoring horses without creating a risk to horse health and wellness.     

Anatomy of the reproductive tract of the female muskox (Ovibos moschatus)

Reproductive tracts from 23 female muskoxen were collected from the Canadian high arctic during annual native muskox hunts. Twenty tracts were collected during the late breeding season and the last third of pregnancy or anoestrus, with 3 additional specimens taken just before the breeding season in August. The non-gravid muskox uterus was very similar to that of sheep and goats except for two features found in parous muskoxen. The first was endometrial pigmentation found only in the caruncles and associated with a dense collection of lipofuscin granules in the endometrial stroma. The second was a prominent 5 mm deep band of muscular tissue protruding from the antimesometrial border of the uterine horns throughout most of their length. The pregnant uterus and the fetal membranes of the muskox resembled homologous structures in domestic ruminants. However, there was no morphological evidence of a corpus luteum during late pregnancy, apart from a luteal scar in the ovary ipsilateral to the pregnant horn. Of the 4 females collected at the end of the breeding season, 2 lactating females were apparently not cyclic while 2 others had more than one CL, suggesting that they had undergone at least 2 cycles without conceiving or remaining pregnant.     

Optimizing Radio Retention and Minimizing Radio Impacts in a Field Study of Upland Sandpipers

Abstract: Two challenges in wildlife telemetry are optimizing the duration of transmitter attachment and minimizing the impacts of radios on the behavior and demography of the study animal. We tested 4 methods of radio attachment for a breeding population of upland sandpipers (Bartramia longicauda) under natural conditions at a tallgrass prairie site in Kansas, USA. To estimate radio retention and weekly survival rates, we used the nest survival model of Program MARK. Radio retention was lowest at the start and the end of the breeding period. The expected duration of radio retention was 1.8 years for a leg-loop harness, 40 days for radios glued to clipped feathers, 26 days for radios glued directly to feathers, and 7 days for radios glued to bare skin. Few radiomarked birds died during our study, but 4 of 8 mortality events were discovered within one week of radiomarking. Both glue and harnesses increased predation risk immediately after radio attachment. The weekly probability of survival was high after a 1-week acclimation period, and the expected survival for a 10-week breeding period was similar in males and females. Attachment of radios with glue had no effect on annual return rates. However, attachment of radios with leg harnesses resulted in lower return rates among radiomarked birds than birds without radios. Radios attached with glue were shed in <1 year but radios attached with harnesses were retained for up to 1-2 years. Our results indicate a tradeoff between optimizing radio retention and minimizing impacts on demography. Glue techniques had retention rates that were suitable for only short-term studies, but attachment with glue had no long-term effect on annual return rates. Leg harnesses provided effective radio retention that had little effect on survival rates during the stationary breeding period, but resulted in lower annual return rates. Robust estimates of radio retention and survival will assist researchers in selecting attachment techniques that best meet the study goals of future telemetry projects.     

Breeding site fidelity and natal philopatry in the Redshank Tringa totanus

This paper presents the results of a study carried out on breeding Redshank in the Ribble Marshes, Lancashire, England.
Redshank tend to return to the same breeding area year after year. There was no detectable sex bias in return rates. Experienced birds were more site faithful than inexperienced birds, with previously successful birds exhibiting the highest degree of breeding site fidelity. Older, more experienced birds were more successful at hatching eggs than inexperienced birds.
Breeding dispersal was the same both within and between years. Faithful pairs and males nesting with a new mate dispersed significantly shorter distances than females nesting with a new partner. Dispersal distances in female Redshank were affected by breeding success: unsuccessful females, nesting with a new mate, dispersed significantly farther than successful females. A pair's breeding success influenced the following year's mate fidelity. However, other factors such as overwintering survival and date of return may also have influenced mate fidelity.
Redshank were highly faithful to their natal area; a high proportion of birds that survived post-fledging mortality returned to breed in their area of birth. No sex bias in natal dispersal was detected. Approximately 50% of Redshank breed in their first year of life.     

Copper concentration in women endometrium and in peripheral blood after prolonged use of intrauterine devices (author's transl)]

66 women were examined to determine the copper concentration in their serum and endometrium after prolonged use of an IUD (Lippes Loop, Hall Ring, Birnberg, Saf-T-Coil, Tatum, and Copper 7). A control of 16 nonusers was included. The level of copper was found by atomic absorption spectrophotometry. In the control group, the copper concentration in the serum was a mean of 100 gamma/100 cc of serum and in the endometrial tissue, a mean of 251 gamma/100 gm/wet tissue. In women using IUDs with no copper, the concentration in the serum was in the normal range, but in endometrial tissue it was between 457-586 gamma/100 gm. Similar findings came with the examination of women using IUDs containing copper. The high concentration of copper in inflamed endometrial tissue led to the hypothesis that such a condition, ith accompanying hyperenemia and hyperkinesia of the uterus and tubes are the principle factors for the contraceptive action of IUDs.     

Comparing the effectiveness of copper intrauterine devices available in Canada. Is FlexiT non-inferior to NovaT when inserted immediately after first-trimester abortion? Study protocol for a randomized controlled trial

ABSTRACT: BACKGROUND: We describe the rationale and protocol for a randomized noninferiority controlled trial (RCT) to determine if the Flexi-T380(+) copper intrauterine contraceptive device (IUD) is comparable in terms of effectiveness and expulsion rates to the most common Canadian IUD currently in use, NovaT-200, when placed immediately after a first-trimester abortion. METHODS: Consenting women choosing to use an IUD after an abortion for a pregnancy of less than 12 weeks of gestation will be randomized to device-type groups to receive immediate post-abortion placement of either a Flexi-T380(+) IUD, a device for which no current evidence on expulsion or effectiveness rates is available, or the Nova-T200 IUD, the only other brand of copper IUD available in Canada at the time of study initiation. The primary outcome measure is IUD expulsion rate at 1 year. Secondary outcomes include: pregnancy rate, method continuation rate, complication rates (infection, perforation), and satisfaction with contraceptive method. A non-intervention group of consenting women choosing a range of other post-abortion contraception methods, including no contraception, will be included for comparison of secondary outcomes. Web-based contraception satisfaction questionnaires, clinical records, and government-linked health administrative databases will be used to assess primary and secondary outcomes. DISCUSSION: The RCT design, combined with access to clinical records at all provincial abortion clinics, and to information in provincial single-payer linked administrative health databases, birth registry, and hospital records, offers a unique opportunity to determine if a novel IUD has a comparable expulsion rate to that of the current standard IUD in Canada, in addition to the first opportunity to determine pregnancy rate and method satisfaction at 1 year post-abortion for women choosing a range of post-abortion contraceptive options. We highlight considerations of design, implementation, and evaluation of the first trial to provide rigorous evidence for the effectiveness of current Canadian IUDs when inserted after first-trimester abortion.Trial registrationClinicalTrials.gov Identifier NCT01174225.