News | IVF: Using Less Medication May Improve Maternal Safety
A multicenter randomized clinical trial published in The BMJ found that natural-cycle endometrial preparation before frozen embryo transfer in ovulating women achieved healthy live birth rates comparable to hormone replacement while significantly reducing several maternal pregnancy complications.
Frozen embryo transfer is increasingly common in IVF because of freeze-all strategies, lower ovarian hyperstimulation risk, and preimplantation genetic testing. Endometrial preparation either relies on natural follicular development and ovulation or uses sequential exogenous estrogen and progesterone in a programmed cycle.
The study enrolled 4,376 ovulating women at 24 academic reproductive centers in China. Before their first single-blastocyst frozen transfer, they were randomized to natural ovulation or programmed hormones. Natural cycles used follicular and luteinizing hormone, estradiol, and progesterone monitoring, with ovulation triggered when clinically indicated; programmed cycles followed standard exogenous-hormone preparation.
Healthy live birth rates were nearly identical: 41% with natural ovulation and 40% with programmed hormones. Maternal safety differed significantly, with higher preeclampsia risk after programmed treatment, especially among women with clinical pregnancies.
Natural ovulation was associated with lower risks of early miscarriage, vaginal bleeding, hypertensive disorders, placenta accreta spectrum, cesarean delivery, and postpartum hemorrhage. Birth weight and serious neonatal complications did not differ significantly.
The higher preeclampsia risk in programmed cycles may relate to the absence of a corpus luteum, which secretes relaxin and vasoactive and angiogenic factors involved in maternal cardiovascular adaptation. These factors were not measured, so the biologically plausible mechanism needs further study.
Programmed cycles were also associated with several later-pregnancy complications potentially related to placental function, suggesting that preconception interventions may have lasting maternal effects.
The team favored natural ovulation for overall safety, especially in women at high risk of hypertensive disorders, including those aged ≥38 or with obesity. It reduced relative preeclampsia risk by about 40%, an absolute difference of about 2 percentage points, with potential public-health importance in countries with high cardiometabolic burden.
Natural cycles had more first-attempt cancellations, but after transfer was reached, maternal and neonatal safety benefits warranted clinical consideration.
News | IVF: Using Less Medication May Improve Maternal Safety
News | IVF: Using Less Medication May Improve Maternal Safety
A multicenter randomized clinical trial published in The BMJ found that natural-cycle endometrial preparation before frozen embryo transfer in ovulating women achieved healthy live birth rates comparable to hormone replacement while significantly reducing several maternal pregnancy complications.
Frozen embryo transfer is increasingly common in IVF because of freeze-all strategies, lower ovarian hyperstimulation risk, and preimplantation genetic testing. Endometrial preparation either relies on natural follicular development and ovulation or uses sequential exogenous estrogen and progesterone in a programmed cycle.
The study enrolled 4,376 ovulating women at 24 academic reproductive centers in China. Before their first single-blastocyst frozen transfer, they were randomized to natural ovulation or programmed hormones. Natural cycles used follicular and luteinizing hormone, estradiol, and progesterone monitoring, with ovulation triggered when clinically indicated; programmed cycles followed standard exogenous-hormone preparation.
Healthy live birth rates were nearly identical: 41% with natural ovulation and 40% with programmed hormones. Maternal safety differed significantly, with higher preeclampsia risk after programmed treatment, especially among women with clinical pregnancies.
Natural ovulation was associated with lower risks of early miscarriage, vaginal bleeding, hypertensive disorders, placenta accreta spectrum, cesarean delivery, and postpartum hemorrhage. Birth weight and serious neonatal complications did not differ significantly.
The higher preeclampsia risk in programmed cycles may relate to the absence of a corpus luteum, which secretes relaxin and vasoactive and angiogenic factors involved in maternal cardiovascular adaptation. These factors were not measured, so the biologically plausible mechanism needs further study.
Programmed cycles were also associated with several later-pregnancy complications potentially related to placental function, suggesting that preconception interventions may have lasting maternal effects.
The team favored natural ovulation for overall safety, especially in women at high risk of hypertensive disorders, including those aged ≥38 or with obesity. It reduced relative preeclampsia risk by about 40%, an absolute difference of about 2 percentage points, with potential public-health importance in countries with high cardiometabolic burden.
Natural cycles had more first-attempt cancellations, but after transfer was reached, maternal and neonatal safety benefits warranted clinical consideration.
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Collected online