The corpus luteum is more than progesterone

Mounting evidence suggests that certain perinatal outcomes in frozen embryo transfer (FET) cycles are affected by the manner of endometrial preparation, likely due to presence or absence a corpus luteum (CL). Since 1984 report successful pregnancy patient with ovarian failure supplemented exogenous estradiol (E2) and progesterone (P4), vitro fertilization programs have used E2 P4 create “programmed” for many their FETs. Programmed FET cycle types offer conveniences, including fewer monitoring visits ability schedule day when convenient provider. Multiple regimens replacement been studied; no differences live birth delivery rates observed among them. However, obstetric neonatal long noted fresh transfers vs. Most significantly, FETs not only associated more hypertensive disorders (HDP) but also lower low weight, small gestational age, preterm delivery, placenta previa, placental abruption, mortality (1Sha T. Yin X. Cheng W. Massey I.Y. Pregnancy-related complications resulting from cryopreserved versus embryos fertilization: meta-analysis.Fertil Steril. 2018; 109: 330-342.e9Abstract Full Text PDF PubMed Scopus (71) Google Scholar). Only recently has it become evident some this difference is explained preparation cycles. Conrad et al. (2Conrad K.P. Petersen J.W. Chi Y.Y. Zhai Li M. Chiu K.H. al.Maternal cardiovascular dysregulation during early after luteum.Hypertension. 2019; 74: 705-715Crossref (28) Scholar) demonstrated CL critical role maternal adaptation pregnancy. The usual adaptations were attenuated absent first trimester women who conceived without Increased HDP reduced aortic compliance (3von Versen-Hoynck F. Schaub A.M. Liu J. Lingis al.Increased preeclampsia risk 73: 640-649Crossref (98) Because sufficient levels achieved all types, factor affecting HDP. It other secretions playing role: relaxin, oxytocin, renin, aldosterone, vascular endothelial growth factor, vasoactive compounds normally secreted. An alternative hypothesis these sequalae stem excessive supplementation typically given hormone-replaced (HRC), rather than deficiency secretions. excellent recent review February issue Fertility Sterility discusses relevant experimental clinical studies date (4Singh B. Reschke L. Segars Baker V.L. Frozen-thawed transfer: potential importance preventing obstetrical complications.Fertil 2020; 113: 252-257Abstract In current journal, large retrospective cohort study Hu (5Hu K.L. Zhang D. R. Endometrium undergoing single blastocyst cycles.Fertil 2021; 115: 1487-1494Abstract (11) adds further support concept. center elective single-embryo based on methods, 21,648 underwent warmed vitrified blastocysts. Cycles compared method preparation: HRCs (with progesterone; n = 2,561), natural (NC; human chorionic gonadotropin trigger; 3,790), stimulated (SC; clomiphene letrozole gonadotropins; 670); 7,145 deliveries analyzed. Ascertainment was uniform across groups. HRC group had higher HDP, very cesarean high weights, premature rupture membranes NC group. SC diabetes delivery. Controlling ovulatory via logistic regression did affect associations. sample size, statistically significant may limited impact. Absolute >3% between groups (6% pregnancies 2% groups), (12% 7%–8% others), mellitus (14% 9%–10% NC). Further, since randomized controlled trial, analysis be biased factors assessed. What we make findings? Surely programmed conveniences plays greater believed few years ago. size worth abandoning most cases? For moment, certainly discussion warranted if being recommended. Hopefully recognized normal process placentation will spur efforts define particular mediating effect, which could lead an enhancement approach avoids increased risk. single-blastocyst cyclesFertility SterilityVol. 115Issue 6PreviewTo investigate association endometrium outcomes. Full-Text