How to proceed with a donor embryo transfer in a female of reproductive age with mild adenomyosis, an 11 mm ovarian cyst, and a thick endometrium on day 3 of her cycle?

Management of Donor Embryo Transfer with Thick Endometrium, Mild Adenomyosis, and 11mm Ovarian Cyst

You should proceed with elective single embryo transfer (eSET) after addressing the ovarian cyst and optimizing endometrial preparation, as ESHRE mandates eSET for all donor embryo transfers regardless of endometrial thickness, mild adenomyosis, or small ovarian cysts. 1

Embryo Transfer Strategy

• Transfer only one embryo - ESHRE provides a strong recommendation that eSET must be practiced for all donated embryo transfers with no exceptions, regardless of previous unsuccessful treatments, endometrial characteristics, patient age, or presence of adenomyosis 2, 1

• The multiple pregnancy rate is 30-fold higher with double embryo transfer compared to repeated single embryo transfer (OR 30.54,95% CI 7.46-124.95), and even singleton pregnancies after double transfer carry higher risks of neonatal death and complications 1

• Cumulative live birth rates with repeated eSET are equivalent to double embryo transfer while avoiding twin risks, pre-eclampsia, gestational diabetes, emergency cesarean section, and preterm labor 1

Management of the 11mm Ovarian Cyst

• This cyst falls into O-RADS category 2 (almost certainly benign) if it appears as a simple cyst less than 10cm, requiring no intervention before embryo transfer 2

• Simple cysts less than 5cm can be managed with optional single follow-up within one year, and do not require removal or delay of embryo transfer 2

• If the cyst has complex features (solid components, irregular walls, or high color score), refer to ultrasound specialist or gynecologist for further characterization before proceeding 2

Addressing the Thick Endometrium on Day 3

• Day 3 endometrial thickness should not delay or alter your transfer plan - ESHRE guidelines state that endometrial characteristics should not determine whether to perform single versus double embryo transfer in frozen embryo transfer cycles 3

• While ultrasound parameters provide information on endometrial receptivity, robust evidence for their predictive value is lacking 3

• The thick endometrium on day 3 may represent normal proliferative phase changes or could indicate endometrial pathology requiring further evaluation with imaging or hysteroscopy if there are concerning features

Managing Mild Adenomyosis

• Adenomyosis does not change the mandatory eSET recommendation - the focus must remain on preventing multiple pregnancy complications, which would be particularly problematic in a uterus with adenomyosis 1

• Consider GnRH agonist pretreatment for 1-6 months before the frozen embryo transfer cycle, as this optimizes live birth rates in women with adenomyosis to match those with normal uteri (50.6% vs 48.2%, p=0.341) 4

• The length of GnRH agonist suppression should be based on uterine size and response to treatment, typically ranging from one to six months 4

• Women with adenomyosis have equivalent implantation rates (54.2% vs 53%, p=0.208) and cumulative live birth rates when properly managed with GnRH agonist protocols 4

Endometrial Preparation Protocol

• Use a down-regulated frozen embryo transfer protocol with GnRH agonist suppression followed by estrogen and progesterone supplementation 5, 4

• Start progesterone supplementation on the day of donor oocyte retrieval or the day after, as starting progesterone the day prior to oocyte pick-up significantly decreases pregnancy rates (OR 1.87,95% CI 1.13-3.08) 5

• No evidence supports adding aspirin, steroids, or hCG administration to improve outcomes 5

Critical Counseling Points

• Explain that transferring two embryos increases risks without improving cumulative live birth rates, including a 20-fold increased risk of ectopic pregnancy 1, 3

• Discuss that the adenomyosis finding increases obstetric risks including preterm delivery and antepartum hemorrhage, making avoidance of multiple pregnancy even more critical 4

• Counsel that eSET is the standard of care for donor embryo transfers to minimize maternal and neonatal complications 1

• Address that previous pregnancy loss or failed cycles do not justify double embryo transfer, as no clinical or embryological factor warrants deviation from eSET in donor embryo cycles 1