Assisted hatching on assisted conception (in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI)).

BACKGROUND: Failure of implantation and conception may result from inability of the blastocyst to escape from its outer coat, which is known as the zona pellucida. Artificial disruption of this coat is known as assisted hatching and has been proposed as a method for improving the success of assisted conception by facilitating embryo implantation. OBJECTIVES: To determine effects of assisted hatching (AH) of embryos derived from assisted conception on live birth and multiple pregnancy rates.  SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Specialised Register (until May 2020), the Cochrane Central Register of Controlled Trials (CENTRAL; until May 2020), in the Cochrane Library; MEDLINE (1966 to May 2020); and Embase (1980 to May 2020). We also searched trial registers for ongoing and registered trials (http://www.clinicaltrials.gov - a service of the US National Institutes of Health; http://www.who.int/trialsearch/Default.aspx - The World Health Organization International Trials Registry Platform search portal) (May 2020). SELECTION CRITERIA: Two review authors identified and independently screened trials. We included randomised controlled trials (RCTs) of AH (mechanical, chemical, or laser disruption of the zona pellucida before embryo replacement) versus no AH that reported live birth or clinical pregnancy data. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. Two review authors independently performed quality assessments and data extraction. MAIN RESULTS: We included 39 RCTs (7249 women). All reported clinical pregnancy data, including 2486 clinical pregnancies. Only 14 studies reported live birth data, with 834 live birth events. The quality of evidence ranged from very low to low. The main limitations were serious risk of bias associated with poor reporting of study methods, inconsistency, imprecision, and publication bias. Five trials are currently ongoing. We are uncertain whether assisted hatching improved live birth rates compared to no assisted hatching (odds ratio (OR) 1.09, 95% confidence interval (CI) 0.92 to 1.29; 14 RCTs, N = 2849; I² = 20%; low-quality evidence). This analysis suggests that if the live birth rate in women not using assisted hatching is about 28%, the rate in those using assisted hatching will be between 27% and 34%. Analysis of multiple pregnancy rates per woman showed that in women who were randomised to AH compared with women randomised to no AH, there may have been a slight increase in multiple pregnancy rates (OR 1.38, 95% CI 1.13 to 1.68; 18 RCTs, N = 4308; I² = 48%; low-quality evidence). This suggests that if the multiple pregnancy rate in women not using assisted hatching is about 9%, the rate in those using assisted hatching will be between 10% and 14%. When all of the included studies (39) are pooled, the clinical pregnancy rate in women who underwent AH may improve slightly in comparison to no AH (OR 1.20, 95% CI 1.09 to 1.33; 39 RCTs, N = 7249; I² = 55%; low-quality evidence). However, when a random-effects model is used due to high heterogeneity, there may be little to no difference in clinical pregnancy rate (P = 0.04). All 14 RCTs that reported live birth rates also reported clinical pregnancy rates, and analysis of these studies illustrates that AH may make little to no difference in clinical pregnancy rates when compared to no AH (OR 1.07, 95% CI 0.92 to 1.25; 14 RCTs, N = 2848; I² = 45%). We are uncertain about whether AH affects miscarriage rates due to the quality of the evidence (OR 1.13, 95% CI 0.82 to 1.56; 17 RCTs, N = 2810; I² = 0%; very low-quality evidence). AUTHORS' CONCLUSIONS: This update suggests that we are uncertain of the effects of assisted hatching (AH) on live birth rates. AH may lead to increased risk of multiple pregnancy. The risks of complications associated with multiple pregnancy may be increased without evidence to demonstrate an increase in live birth rate, warranting careful consideration of the routine use of AH for couples undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). AH may offer a slightly increased chance of achieving a clinical pregnancy, but data quality was of low grade. We are uncertain about whether AH influences miscarriage rates.

Thyroxine replacement for subfertile women with euthyroid autoimmune thyroid disease or subclinical hypothyroidism.

BACKGROUND: Thyroid disease is the second most common endocrine disorder affecting women of reproductive age. Subclinical hypothyroidism is diagnosed by an elevated thyroid-stimulating hormone concentration with a normal concentration of free thyroxine hormone. Autoimmune thyroid disease (ATD) is diagnosed by the presence of thyroid autoantibodies, regardless of thyroid hormone levels. Thyroxine may be a useful treatment for subfertile women with these two specific types of thyroid disease for improving pregnancy outcomes during assisted reproduction. OBJECTIVES: To evaluate the efficacy and harms of levothyroxine replacement in subfertile women with subclinical hypothyroidism or with normal thyroid function and thyroid autoimmunity (euthyroid autoimmune thyroid disease, or euthyroid ATD) undergoing assisted reproduction. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility (CGF) Group specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and two trials registers together with reference checking and contact with study authors and experts in the field to identify studies. We searched for all published and unpublished randomised controlled trials (RCTs) comparing thyroxine with no treatment or placebo, without language restrictions, from inception to 8 April 2019, and in consultation with the Cochrane CGF Information Specialist. SELECTION CRITERIA: We included women undergoing assisted reproduction treatment, meaning both in vitro fertilisation and intracytoplasmic sperm injection, with a history of subfertility and with subclinical hypothyroidism or with euthyroid ATD. We excluded women with a previously known clinical hypothyroidism or already taking thyroxine or tri-iodothyronine. RCTs compared thyroxine (levothyroxine) with either placebo or no treatment. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary review outcomes were live birth and adverse events of thyroxine; our secondary outcomes were clinical pregnancy, multiple pregnancy and miscarriage. MAIN RESULTS: The review included four studies with 820 women. The included studies were of overall low risk of bias. Using GRADE methodology, we assessed the quality of evidence for the primary outcomes of this review to be very low- to low-quality evidence. Evidence was downgraded for imprecision as it was based on single, small trials with wide confidence intervals (CI). We were able to include data from three of the four included studies.In one study of women with both subclinical hypothyroidism and positive or negative anti-TPO antibodies (autoimmune disease), the evidence suggested that thyroxine replacement may have improved live birth rate (RR 2.13, 95% CI 1.07 to 4.21; 1 RCT, n = 64; low-quality evidence) and it may have led to similar miscarriage rates (RR 0.11, 95% CI 0.01 to 1.98; 1 RCT, n = 64; low-quality evidence). The evidence suggested that women with both subclinical hypothyroidism and positive or negative anti-TPO antibodies would have a 25% chance of a live birth with placebo or no treatment, and that the chance of a live birth in these women using thyroxine would be between 27% and 100%.In women with normal thyroid function and thyroid autoimmunity (euthyroid ATD), treatment with thyroxine replacement compared with placebo or no treatment may have led to similar live birth rates (risk ratio (RR) 1.04, 95% CI 0.83 to 1.29; 2 RCTs, number of participants (n) = 686; I2 = 46%; low-quality evidence) and miscarriage rates (RR 0.83, 95% CI 0.47 to 1.46, 2 RCTs, n = 686, I2 = 0%; low-quality evidence). The evidence suggested that women with normal thyroid function and thyroid autoimmunity would have a 31% chance of a live birth with placebo or no treatment, and that the chance of a live birth in these women using thyroxine would be between 26% and 40%.Adverse events were rarely reported. One RCT reported 0/32 in the thyroxine replacement group and 1/32 preterm births in the control group in women diagnosed with subclinical hypothyroidism and positive or negative anti-TPO antibodies. One RCT reported 21/300 preterm births in the thyroxine replacement group and 19/300 preterm births in the control group in women diagnosed with positive anti-TPO antibodies. None of the RCTs reported on other maternal pregnancy complications, foetal complications or adverse effects of thyroxine. AUTHORS' CONCLUSIONS: We could draw no clear conclusions in this systematic review due to the very low to low quality of the evidence reported.