Decrease in peripheral natural killer cell level during early pregnancy predicts live birth among women with...

Area of Science:

• Reproductive immunology
• Maternal-fetal medicine
• Cellular immunology

Background:

• Peripheral natural killer (NK) cell levels typically decrease in later pregnancy stages.
• The role of NK cell level changes in early pregnancy and their impact on outcomes in unexplained recurrent pregnancy loss (URPL) remain underexplored.
• Previous research suggests trophoblast cells may inhibit peripheral NK cell proliferation.

Purpose of the Study:

• To compare prepregnancy and early pregnancy peripheral NK cell levels in women with URPL.
• To determine if changes in peripheral NK cell levels from prepregnancy to early pregnancy can predict live birth rates.
• To develop a predictive model for live birth in URPL.

Main Methods:

• Prospective cohort study of 252 women with URPL.
• Peripheral NK cell levels measured prepregnancy and in early gestation (4-6 weeks).
• Women categorized into groups with decreased or stable/increased NK cells; outcomes analyzed using statistical tests.
• Multivariable logistic regression and nomogram developed for live birth prediction, validated with ROC curve analysis.

Main Results:

• Over 60% of women showed decreased peripheral NK cell levels in early pregnancy compared to prepregnancy.
• The group with decreased early-gestational NK cells had a significantly higher live birth rate (89.0%) than the other group (49.0%).
• Decreased peripheral NK cell levels and higher anti-Müllerian hormone levels were significant predictors of live birth.

Conclusions:

• A decrease in peripheral natural killer cell levels during early gestation is observed in a majority of women with URPL.
• This decrease in peripheral NK cell levels may serve as a valuable predictor for live birth rates in women experiencing URPL.
• A predictive model incorporating NK cell levels demonstrated good accuracy in assessing live birth potential.