Bed rest after embryo transfer: a randomized controlled trial

Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses

BACKGROUND

Several interventions and techniques are suggested to improve the outcome of embryo transfer (ET) in assisted conception. However, there remains no consensus on the optimal practice, with high variations among fertility specialists.

OBJECTIVE AND RATIONALE

We conducted a comprehensive systematic review and meta-analyses of randomized controlled trials (RCTs) aiming to identify effective interventions that could be introduced around the time of ET to improve reproductive outcomes.

SEARCH METHODS

We searched the electronic databases (MEDLINE, EMBASE and Cochrane CENTRAL) from inception until March 2021 using a multi-stage search strategy of MeSH terms and keywords, and included all RCTs that evaluated an intervention in the 24-h period before/after ET in women undergoing IVF/ICSI. Our primary outcome was clinical pregnancy rate post-ET confirmed as viable pregnancy on ultrasound scan. We assessed the risk of bias in included trials and extracted data in duplicate. We pooled data using a random-effect meta-analysis and reported using risk ratio (RR) with 95% CI. We explored publication bias and effect modifiers using subgroup analyses.

OUTCOMES

Our search yielded 3685 citations of which we included 188 RCTs (38 interventions, 59 530 participants) with a median sample size of 200 (range 26-1761). The quality of included RCTs was moderate with most showing a low risk of bias for randomization (118/188, 62.8%) and attrition (105/188, 55.8%) but there was a significant risk of publication bias (Egger's test P = 0.001). Performing ET with ultrasound guidance versus clinical touch (n = 24, RR 1.265, 95% CI 1.151-1.391, I2 = 38.53%), hyaluronic acid versus routine care (n = 9, RR 1.457, 95% CI 1.197-1.261, I2 = 46.48%) and the use of a soft versus hard catheter (n = 27, RR 1.122, 95% CI 1.028-1.224, I2 = 57.66%) led to higher clinical pregnancy rates. Other pharmacological add-ons also showed a beneficial effect including granulocyte colony-stimulating factor (G-CSF: n = 4, RR 1.774, 95% CI 1.252-2.512, I2 = 0), Atosiban (n = 7, RR 1.493, 95% CI 1.184-1.882, I2 = 68.27%) and hCG (n = 17, RR 1.232, 95% CI 1.099-1.382, I2 = 57.76%). Bed rest following ET was associated with a reduction in clinical pregnancy (n = 6, RR 0.857, 95% CI 0.741-0.991, I2 = 0.01%). Other commonly used interventions, such as non-steroidal anti-inflammatory drugs, prophylactic antibiotics, acupuncture and cervical mucus removal, did not show a significant benefit on reproductive outcomes. Our effect estimates for other important outcomes, including miscarriage and live birth, were limited by the varied reporting across included RCTs.

WIDER IMPLICATIONS

Using ultrasound guidance, soft catheters and hyaluronic acid at the time of ET appears to increase clinical pregnancy rates. The use of Atosiban, G-CSF and hCG showed a trend towards increased clinical pregnancy rate, but larger trials are required before adopting these interventions in clinical practice. Bed rest post-ET was associated with a reduction in clinical pregnancy and should not be recommended.

Physical and Sedentary Activities in Association with Reproductive Outcomes among Couples Seeking Infertility Treatment: A Prospective Cohort Study

BACKGROUND

The aim of this study was to investigate the association of physical activity (PA) with assisted reproductive technology (ART) treatment and pregnancy outcomes among couples seeking infertility treatment.

METHODS

This prospective cohort study was carried out among 128 infertile individuals (64 couples), entering the infertility clinic for ART procedures. Baseline PA (before entering any treatment) was assessed using accelerometry for both women and men. For every couple the infertility treatment outcomes were recorded.

RESULTS

The couples that required invasive ART procedures such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) spent less time in vigorous PA (-73 min/week per couple, woman + man) than those couples who became spontaneously pregnant after entering the study (p = 0.001). We observed no significant associations between the time spent in physical activities and positive pregnancy test or live birth.

CONCLUSIONS

Our results do not support a positive nor negative relation between the time the couples spent in physical activities and the chances of getting pregnant or having a baby among patients seeking infertility treatment. However, couples undergoing invasive ART procedures did less vigorous PA than couples that became spontaneously pregnant, suggesting that PA may interfere with their reproductive health.

The association between level of physical activity and pregnancy rate after embryo transfer: a prospective study

RESEARCH QUESTION

Is physical activity after embryo transfer, as assessed by a smart band activity tracker, associated with decreased pregnancy rates?

DESIGN

Prospective observational cohort study comprising infertile women aged < 38 years, who had undergone fewer than three previous embryo transfers, achieved a good ovarian response and were undergoing frozen-thawed embryo transfer in a tertiary-referral centre. A validated smart band activity tracker was used to assess physical activity level immediately after the embryo transfer and until the pregnancy test. No specific recommendations were given to participants on level or intensity of physical activity. Physicians and patients were blinded to the data stored in the pedometer. Primary outcome was ongoing pregnancy rate.

RESULTS

Fifty women met the inclusion criteria. Ongoing pregnancy rate was 30%. In a pooled analysis, participants walked significantly fewer steps per day on the day of embryo transfer compared with the first 2 days after embryo transfer (4075, interquatile range [IQR] 2932-5592 versus 5204, IQR4203-8584, P = 0.01). No significant difference was observed between pregnant women and non-pregnant women in the median steps per day after embryo transfer until serum beta-HCG was measured (7569, IQR 6008-10884 versus 6572.5, IQR 5299-8786, P = 0.43). No significant difference was observed in the median number of steps on the day of embryo transfer or the first 2 days after embryo transfer between pregnant and non-pregnant women.

CONCLUSIONS

A quantitative objective assessment of the association between physical activity and pregnancy rates after frozen-thawed embryo transfer was conducted. Ambulation after embryo transfer has no adverse effect on pregnancy rates and, therefore, women should resume regular activity immediately after embryo transfer.

Maternal physical activity and sedentary behaviour before and during in vitro fertilization treatment: a longitudinal study exploring the associations with controlled ovarian stimulation and pregnancy outcomes

PURPOSE

To evaluate the association of objectively measured physical activity (PA) and sedentary behaviour before and during in vitro fertilization (IVF) with controlled ovarian stimulation (COS) and pregnancy outcomes.

METHODS

This longitudinal study involved 107 infertile women undergoing IVF treatment. PA and sedentary behaviour were measured for 14 consecutive days using accelerometry as follows: (1) before IVF treatment, (2) during IVF at the implantation time, immediately after embryo transfer, and (3) after positive pregnancy test. Total screen time was assessed by questionnaires. COS results were measured as the number of oocytes and embryos obtained, and the study outcomes included positive hCG, clinical pregnancy, and live birth.

RESULTS

Compared with baseline activity levels, women significantly reduced their PA and increased sedentary behaviour during IVF (p ≤ 0.001). Higher average PA, light PA, and ratio between breaks in every ≥ 30-min blocks of sedentary time showed positive associations, while sedentary time, number, and time accumulated in blocks of ≥ 30 min of sedentary time associated negatively with oocyte and embryo counts (all p < 0.05). Women with high total screen time during non-work days (≥ 7 h) obtained 4.7 oocytes (p = 0.005) and 2.8 embryos (p = 0.008) less in COS. PA and sedentary behaviour before and during IVF did not affect the positive hCG, clinical pregnancy, and live birth outcomes.

CONCLUSION

Our study results suggest that higher time spent in PA and lower time spent in sedentary behaviour before entering assisted reproduction is associated with better COS outcomes, while activity levels before and during IVF do not affect the implantation, pregnancy, and live birth outcomes.

Embryo transfer techniques

Embryo transfer is the final and rate-limiting step of the assisted reproductive technique. Few advances have occurred in the last few decades with regard to this procedure. Studies conducted thus far have focused on factors and interventions taking place before, during and after this procedure. These factors are highly varied and range from methods to improve the psychological state of the patients to methods aimed at reducing uterine contractility and methods aimed at optimising the precise transfer of the embryo. The key question is which factors and interventions have thus far been proven to increase pregnancy rates and live birth rates. This paper aims to review the evidence relating to embryo transfer techniques in a systematic manner with a view to provide practical recommendations to practitioners involved in the procedure.

Immobilization or mobilization after IUI: an RCT

STUDY QUESTION

Does 15 min of immobilization after IUI improve pregnancy rates?

SUMMARY ANSWER

Immobilization for 15 min after IUI does not improve pregnancy rates.

WHAT IS KNOWN ALREADY

Prior RCTs report a beneficial effect of supine immobilization for 15 min following IUI compared to immediate mobilization, however, these studies can be criticized. Given the importance for the logistics in daily practice and the lack of biological plausibility we planned a replication study prior to potential implementation of this procedure.

STUDY DESIGN, SIZE, DURATION

A single centre RCT, based in an academic setting in the Netherlands, was performed. Participants were randomly assigned for 15 min of supine immobilization following IUI for a maximum of six cycles compared to the standard procedure of immediate mobilization following IUI. Participants and caregivers were not blinded to group assignment. An independent researcher used computer-generated tables to allocate treatments. Stratification occurred to the indication of IUI (unexplained or mild male subfertility). Revelation of allocation took place just before the insemination by the caregiver. The primary outcome was ongoing pregnancy rate per couple.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 498 couples diagnosed with unexplained or mild male subfertility and an indication for treatment with IUI were approached and randomized in the study, of which 244 participants were assigned to 15 min of supine immobilization and 254 participants to immediate mobilization.

MAIN RESULTS AND THE ROLE OF CHANCE

Participant characteristics were comparable between the groups, and 236 participants were analysed in the immobilization group, versus 245 in the mobilization group. The ongoing pregnancy rate per couple was not found to be superior in the immobilization group (one-sided P-value = 0.97) with 76/236 ongoing pregnancies (32.2%) being accomplished in the immobilization and 98/245 ongoing pregnancies (40.0%) in the immediate mobilization group (relative risk 0.81; 95% CI [0.63, 1.02], risk difference: -7.8%, 95% CI [-16.4%, 0.8%]). No difference was found in miscarriage rate, multiple gestation rate, live birth rate and time to pregnancy between the groups.

LIMITATIONS, REASONS FOR CAUTION

Owing to discontinuation of the planned treatment not all participants reached six IUI cycles or an ongoing pregnancy. However, this is as expected in IUI treatment and mirrors clinical practice. These participants were equally distributed across the two groups. Women with tubal pathology and endocrine disorders were excluded for this trial, and this might narrow generalizability.

WIDER IMPLICATIONS OF THE FINDINGS

This study shows no positive effect of 15 min of immobilization following IUI on pregnancy rates. Based on available evidence today, including our study, a possible beneficial effect of supine immobilization after IUI is at least doubtful and straightforward implementation does not seem to be justified.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received. All authors have nothing to disclose.

TRIAL REGISTRATION NUMBER

Dutch Trial Register NTR 2418.

TRIAL REGISTRATION DATE

20 July 2010.

DATE OF FIRST PATIENT's ENROLMENT

11 August 2010.

Post-embryo transfer interventions for assisted reproduction technology cycles

BACKGROUND

In women undergoing in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), embryos transferred into the uterine cavity can be expelled due to many factors including uterine peristalsis and contractions, low site of deposition and negative pressure generated when removing the transfer catheter. Techniques to reduce the risk of embryo loss following embryo transfer (ET) have been described but are not standard in all centres conducting ET.

OBJECTIVES

To evaluate the efficacy of interventions used to prevent post-transfer embryo expulsion in women undergoing IVF and ICSI.

SEARCH METHODS

We searched the Menstrual Disorders and Subfertility Group Specialised Register of controlled trials to June 2014 and PubMed, MEDLINE, EMBASE, CENTRAL, PsycINFO, CINAHL, World Health Organization ICTRP, and trial registers from inception to June 2014, with no language restrictions. Additionally, we handsearched reference lists of relevant articles, and ESHRE and ASRM conference abstracts.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions used to prevent post-transfer embryo expulsion in women undergoing IVF and ICSI. Two review authors independently screened titles and abstracts and reviewed the full-texts of all potentially eligible citations to determine whether they met our inclusion criteria. Disagreements were resolved by consensus.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of included trials using standardised, piloted data extraction forms. Data were extracted to allow intention-to-treat analyses. Disagreements were resolved by consensus. The overall quality of the evidence was rated using GRADE methods.

MAIN RESULTS

We included four RCTs (n = 1392 women) which administered the following interventions: bed rest (two trials), fibrin sealant (one trial), and mechanical closure of the cervix (one trial). Our primary outcome, live birth rate, was not reported in any of the included trials; nor were the data available from the corresponding authors. For the ongoing pregnancy rate, two trials comparing more bed rest with less bed rest showed no evidence of a difference between groups (odds ratio (OR) 0.88; 95% confidence interval (CI) 0.60 to 1.31, 542 women, I(2) = 0%, low quality evidence). Secondary outcomes were sporadically reported with the exception of the clinical pregnancy rate, which was reported in all of the included trials. There was no evidence of a difference in clinical pregnancy rate between more bed rest and less bed rest (OR 0.88; 95% CI 0.60 to 1.31, 542 women, I(2) = 0%, low quality evidence) or between fibrin sealant and usual care (OR 0.98; 95% CI 0.54 to 1.78, 211 women, very low quality evidence). However, mechanical closure of the cervix was associated with a higher clinical pregnancy rate than usual care (OR 1.92; 95% CI 1.40 to 2.63, very low quality evidence). The quality of the evidence was rated as low or very low for all outcomes. The main limitations were failure to report live births, imprecision and risk of bias. Overall, the risk of bias of the included trials was high. The use of a proper method of randomisation and allocation concealment was fairly well reported, while only one trial clearly reported blinding. There was no evidence that any of the interventions had an effect on adverse event rates but data were too few to reach any conclusions.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support any specific length of time for women to remain recumbent, if at all, following embryo transfer, nor is there sufficient evidence to recommend the use of fibrin sealants added to the embryo transfer fluid. There is very limited evidence to support the use of mechanical pressure to close the cervical canal following embryo transfer. Further well-designed and powered studies are required to determine the true effectiveness and safety of these interventions.

Association of physical activity in the past year and immediately after in vitro fertilization on pregnancy

OBJECTIVE

To estimate the association of physical activity on in vitro fertilization (IVF).

DESIGN

Prospective cohort study.

SETTING

Academic infertility clinic.

PATIENT(S)

Women (n = 121) undergoing nondonor IVF embryo transfer (fresh or frozen).

INTERVENTION(S)

The women completed a questionnaire on past year physical activity and wore an accelerometer from embryo transfer to serum pregnancy testing.

MAIN OUTCOME MEASURE(S)

Implantation, intrauterine gestation, and live birth.

RESULT(S)

Based on self-reported past year physical activity, the adjusted odds of intrauterine gestation was higher among those that had higher continuous active living (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.09-3.50), sports/exercise (OR 1.48, CI 1.02-2.15), and total activity (OR 1.52, 95%CI 1.15-2.01) indices. After embryo transfer, women did almost no vigorous activity (median 0 min/d) as measured by the accelerometer. More of their time was spent in light activity (median 3.0 h/d) and sedentary behaviors (median 9.3 h/d). Accelerometer-measured physical activity and sedentary behavior after embryo transfer were not associated with any IVF outcome.

CONCLUSION(S)

An active lifestyle in the preceding year favorably impacted the IVF outcome. After embryo transfer, women engaged in mostly light physical activity and sedentary behaviors; therefore, the impact of vigorous physical activity on implantation could not be determined.

Perceptions among infertile couples of lifestyle behaviors and in vitro fertilization (IVF) success

PURPOSE

To assess how patients perceive various lifestyle behaviors impact IVF success.

METHODS

Cross-sectional study of heterosexual, English-speaking couples (n = 138) who completed web-based surveys during IVF treatment cycle. Perceived impact of lifestyle choices assessed by multivariable logistic regression and p-value tests for linear trend (Pt).

RESULT(S)

During the IVF cycle, most patients consider it helpful for women to exercise (76 %), avoid stress (87 %) and limit activity after embryo transfer (92 %). The majority of patients (62 %) consider rigorous exercise (4+ h/week) helpful and nearly one-third (32 %) perceive benefit to complete bed rest after transfer. Overall, couples with a sex-specific infertility diagnosis are more likely to consider partner's lifestyle choices impactful: male-factor couples are more likely to consider it helpful for men to limit cellular phone use (OR:2.73,CI:1.06-7.04) and diminished ovarian reserve couples are more likely to consider it helpful for women to limit exposure to plastics (OR:2.38,CI:1.03-5.51). Patients at higher levels of education (Pt < 0.01) and income (P(t) < 0.01) are less likely to consider lifestyle impactful.

CONCLUSION(S)

Patient perceptions of the impact of lifestyle factors on IVF success vary by sex, infertility diagnosis and socioeconomic factors. Despite counseling to the contrary, many patients perceive benefit to rigorous exercise during the IVF cycle and complete bedrest following transfer. Results provide insight into patient beliefs and highlight opportunities to improve patient education, alleviate patient anxieties and potentially improve IVF outcomes.

Modeling Embryo Transfer into a Closed Uterine Cavity

Embryo transfer (ET) is the last manual intervention after extracorporeal fertilization. After the ET procedure is completed, the embryos are conveyed in the uterus for another two to four days due to spontaneous uterine peristalsis until the window time for implantation. The role of intrauterine fluid flow patterns in transporting the embryos to their implantation site during and after ET was simulated by injection of a liquid bolus into a two-dimensional liquid-filled channel with a closed fundal end via a liquid-filled catheter inserted in the channel. Numerical experiments revealed that the intrauterine fluid field and the embryos transport pattern were strongly affected by the closed fundal end. The embryos re-circulated in small loops around the vicinity where they were deposited from the catheter. The transport pattern was controlled by the uterine peristalsis factors, such as amplitude and frequency of the uterine walls motility, as well as the synchronization between the onset of catheter discharge and uterine peristalsis. The outcome of ET was also dependent on operating parameters such as placement of the catheter tip within the uterine cavity and the delivery speed of the catheter load. In conclusion, this modeling study highlighted important parameters that should be considered during ET procedures in order to increase the potential for pregnancy success.

Post-embryo transfer interventions for in vitro fertilization and intracytoplasmic sperm injection patients

BACKGROUND

Techniques for embryo transfer (ET) are being developed, optimized, and standardized to provide the best outcomes.This includes methods to reduce the risk of embryo loss following ET.

OBJECTIVES

To systematically locate, analyse, and review the best available evidence regarding the effectiveness of post-ET techniques for women undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

SEARCH STRATEGY

We searched electronic databases; reference lists of primary studies, review articles, and relevant publications; and conference abstracts. No language restrictions were applied.

SELECTION CRITERIA

Screening and selection of 2436 possible trial citations were performed independently by two review authors. Four prospective, truly randomised trials met the inclusion criteria. The trials compared two competing post ET interventions or an intervention versus no treatment in women undergoing IVF and ICSI.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected data and assessed risk of bias using a standardized data extraction form. Individual outcome data were extracted to support an intention-to-treat analysis.

MAIN RESULTS

The primary outcome, live birth rate, was not reported in any of the included trials. The ongoing pregnancy rate was only available for one trial that compared immediate ambulation with 30 minute bed rest, with no evidence of an effect with bed rest (OR 1.00; 95% CI 0.54 to 1.85).Secondary outcomes were sporadically reported with the exception of clinical pregnancy rate, which was reported in all of the included trials. There was no significant difference between less bed rest and more rest (OR 1.13; 95% CI 0.77 to 1.67). Nor was there any significant difference between the use of a fibrin sealant and control (OR 0.98; 95% CI 0.54 to 1.78). Even so, there was a significantly higher probability of pregnancy following mechanical closure of the cervix compared with no intervention (OR 1.92; 95% CI 1.40 to 2.63).The risk of bias of the included studies was variable. The reporting of a proper method of randomisation and allocation concealment was demonstrated in the majority of trials, while only one trial was reported to be blinded.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support a certain amount of time for women to remain recumbent following ET, or to support the use of fibrin sealants. Finally, there is limited evidence to support the use of mechanical closure of the cervical canal following ET. Further well-designed and powered studies are required to determine the true effect, if any, of these and other post ET techniques for women undergoing IVF and ICSI.