Fertility restoration in mice with chemotherapy induced ovarian failure using differentiated iPSCs

BACKGROUND

Treatment options for premature ovarian insufficiency (POI) are limited to hormone replacement and donor oocytes. A novel induced pluripotent stem cell (iPSC) transplant paradigm in a mouse model has potential translational applications for management of POI.

METHODS

Mouse ovarian granulosa cell derived-iPSCS were labelled with green fluorescent protein (GFP) reporter and differentiated in vitro into oocytes. Differentiated cells were assayed for estradiol and progesterone secretion by enzyme-linked immunosorbent assays. After Fluorescence-Activated Cell Sorting (FACS) for the cell surface marker anti-Mullerian hormone receptor (AMHR2), enriched populations of differentiated cells were surgically transplanted into ovaries of mice that had POI secondary to gonadotoxic pre-treatment with alkylating agents. A total of 100 mice were used in these studies in five separate experiments with 56 animals receiving orthotopic ovarian injections of either FACS sorted or unsorted differentiated iPSCSs and the remaining animals receiving sham injections of PBS diluent. Following transplantation surgery, mice were stimulated with gonadotropins inducing oocyte development and underwent oocyte retrieval. Nine transplanted mice were cross bred with wild-type mice to assess fertility. Lineage tracing of resultant oocytes, F1 (30 pups), and F2 (42 pups) litters was interrogated by GFP expression and validation by short tandem repeat (STR) lineage tracing.

FINDINGS

[1] iPSCs differentiate into functional oocytes and steroidogenic ovarian cells which [2] express an ovarian (GJA1) and germ cell (ZP1) markers. [3] Endocrine function and fertility were restored in mice pretreated with gonadotoxic alkylating agents via orthotopic transplantation of differentiated iPSCS, thus generating viable, fertile mouse pups.

INTERPRETATION

iPSC-derived ovarian tissue can reverse endocrine and reproductive sequelae of POI.

FUNDING

Center for Infertility and Reproductive Surgery Research Award, Siezen Foundation award (RMA). Reproductive Scientist Development Program, Marriott Foundation, Saltonstall Foundation, Brigham Ovarian Cancer Research Fund (K.E).

The clinical relevance of luteal phase progesterone support in true natural cycle cryopreserved blastocyst stage embryo transfers: a retrospective cohort study

Background

More than 67% of all embryos transferred in the United States involve frozen-thawed embryos. Progesterone supplementation is necessary in medicated cycles to luteinize the endometrium and prepare it for implantation, but little data is available to show if this is beneficial in true natural cycles. We evaluated the use of luteal phase progesterone supplementation for cryopreserved/warmed blastocyst transfers in true natural cycles not using an ovulatory trigger.

Methods

Retrospective cohort study in a single academic medical center. We studied the use of luteal phase progesterone supplementation in patients undergoing true natural cycle cryopreserved blastocyst embryo transfers. Our primary outcome measure was ongoing pregnancy rate, with other pregnancy outcomes being evaluated (i.e. implantation rate, miscarriage rate, ectopic rate, and multifetal gestation). Categorical data were analyzed utilizing Fisher’s exact test and all binary variables were analyzed using log-binomial regression to produce a risk ratio.

Results

Two hundred twenty-nine patients were included in the analysis with 149 receiving luteal phase progesterone supplementation and 80 receiving no luteal phase support. Patient demographic and cycle characteristics, and embryo quality were similar between the two groups. No difference was seen in ongoing pregnancy rate (49.0% vs. 47.5%, p = 0.8738), clinical pregnancy rate (50.3% vs. 47.5%, p = 0.7483), positive HCG rate (62.4% vs. 57.5%, p = 0.5965), miscarriage/abortion rate (5.4% vs. 2.5%, p = 0.2622), ectopic pregnancy rate (0% vs. 1.3%, p = 0.3493), or multifetal gestations (7.4% vs. 3.8%, p = 0.3166).

Conclusion(s)

The addition of luteal phase progesterone support in true natural cycle cryopreserved blastocyst embryo transfers did not improve pregnancy outcomes and therefore the routine use in practice cannot be recommended based on this study, but the utilization should not be discouraged without further studies.

Capsule

Progesterone supplementation as luteal phase support in true natural cycle cryopreserved blastocyst transfers does not improve ongoing pregnancies.