In a retrospective cohort, blastocyst cleavage, compaction, and quality patterns were evaluated for associations with live birth rates.

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Frontiers in Medicine Published April 16, 2026 Medically reviewed April 25, 2026 DOI ↗ By Dr. Sofia Müller, MD · Lifespan & Whole-Person Care

Key Takeaway

Note that blastocyst morphology and age predict live birth, but abnormal cleavage did not independently affect live birth in adjusted models.

This retrospective time-lapse cohort study evaluated 3,103 transferred autologous blastocysts to determine the relationship between early developmental patterns and subsequent pregnancy outcomes. The exposure included cleavage patterns (normal or abnormal), morula compaction degrees (full or partial), and blastocyst quality categories (top, good, or low). Primary outcomes focused on live birth, with secondary outcomes including pregnancy and clinical pregnancy rates.

Results indicated that 92.5% of blastocysts originated from normally dividing embryos, and 63.8% of these developed into fully compacted morulas. In unadjusted analyses, fully compacted morulas were associated with higher live birth rates compared to partially compacted ones, while embryos with abnormal cleavage showed lower rates than those with partial morulas from normal cleavage. The highest observed live birth rate was 38.9%, occurring in top-quality blastocysts that originated from normally cleaving, fully compacted morulas.

Multivariable modeling identified blastocyst morphology and blastocyst age as the strongest independent predictors of clinical outcome, with maternal age showing a consistent negative association. While abnormal cleavage remained associated with reduced pregnancy and clinical pregnancy rates in adjusted models, this association did not persist for live birth. Compaction pattern did not retain statistical significance after adjustment. Safety data, including adverse events or tolerability, were not reported.

The study concludes that blastocyst morphology and developmental day remain the primary determinants of live birth after single blastocyst transfer. However, because this is an observational study, causality cannot be inferred. The lack of reported safety data and the reliance on retrospective data limit the ability to generalize these findings to all clinical settings without further prospective validation.

Study Details

Study typeCohort

EvidenceLevel 3

PublishedApr 2026

View Original Abstract ↓

IntroductionThis retrospective time lapse study evaluated 3,103 transferred autologous blastocysts to determine how early division patterns, morula compaction behavior and blastocyst quality influence clinical outcomes.MethodsEmbryos were categorised by cleavage pattern (normal or abnormal), degree of morula compaction (full or partial), and blastocyst quality (top, good or low).ResultMost transferred blastocysts, 92.5%, originated from normally dividing embryos, of which 63.8% developed into fully compacted morulas. In unadjusted analyses, fully compacted morulas resulted in higher pregnancy, clinical pregnancy and live birth rates than partially compacted morulas across all morphology categories. Embryos with abnormal cleavage constituted 7.5% of the cohort, developed almost exclusively into partial morulas, and showed reduced reproductive potential, with lower pregnancy and clinical pregnancy rates compared with normally dividing embryos, and lower live birth rates compared with partial morulas originating from normal cleavage. The highest live birth rate (38.9%) was observed for top quality blastocysts originating from normally cleaving, fully compacted morulas. In multivariable models adjusting for maternal age and blastocyst developmental day, blastocyst morphology and blastocyst age were the strongest independent predictors of clinical outcome, while maternal age showed a consistent negative association. Abnormal cleavage remained associated with reduced pregnancy and clinical pregnancy rates, although this effect did not persist for live birth, and compaction pattern did not retain significance after adjustment.DiscussionOverall, early developmental behavior, particularly cleavage pattern and morula compaction, aligns with downstream morphology to shape embryo competence, while blastocyst morphology and blastocyst developmental day remain the primary determinants of live birth after single blastocyst transfer.

In a retrospective cohort, blastocyst cleavage, compaction, and quality patterns were evaluated for associations with live birth rates.

Study Details

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In a retrospective cohort, blastocyst cleavage, compaction, and quality patterns were evaluated for associations with live birth rates.

Study Details

Axillary ultrasound did not improve sentinel lymph node detection rates compared to clinical examination alone in early-stage breast cancer patients.

Ultrasound scans did not change breast cancer surgery outcomes in this large study

Clinical research that matters. Delivered to your inbox.

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