Hypoxia leads to diminished ovarian reserve in an age dependent manner

OBJECTIVES

Perinatal hypoxia causes premature activation and initiation of growth in dormant follicles, leading to diminished ovarian reserve. An indirect mechanism such as the release of stress-related hormones, may influence ovarian follicle recruitment under hypoxic conditions. We wanted to determine whether hypoxic ovarian damage results from increased follicle growth and "burnout" or from increased apoptosis, and whether this damage is age-dependent.

DESIGN

Animal study Participants/Materials, Setting, Methods: Using adult 6-week-old (n=8) and one-day-old newborn (n=20) ICR (CD-1) female mice, ovarian follicular counts were conducted on H&E-stained sections.

METHODS

Immunohistochemistry was performed on sections stained with Ki-67, anti-Caspase 3 and anti-FOXO3A.

RESULTS

Exposure to hypoxia resulted in significantly reduced proportion of primordial follicles vs normoxia in both adult dams and newborn pups (3.17±2.75% vs. 17.89±4.4%; p=0.004; 40.59±14.88% vs. 81.92±31.56%, p=0.001, respectively), concomitant with increased growing- primary and secondary follicles, and more pronounced in adult dams vs newborn pups (6-fold vs. 2-fold, respectively). Ki67 staining revealed higher scores of cell proliferation in follicular granulosa cells after exposure to hypoxia than normoxia. However, Caspase 3 and Foxo3A staining did not show any differences in these markers of apoptosis in oocytes, granulosa cells, theca cells, or stromal cells when exposed to hypoxia versus normoxia.

LIMITATIONS

The current study has several limitations; first, the sample size for each group is relatively small, which could limit the generalizability of the findings. Second, the study uses an ex vivo culture system, which may not fully capture the complex interactions that occur in the whole animal. Third, the exposure to hypoxia only lasted for 3 hours, which may not be long enough to observe all the potential effects. In addition, the study only analyzed specific markers of apoptosis in a few cell types, and other cell types or apoptotic pathways might be involved. Lastly, the study provides evidence for accelerated follicular activation and decreased ovarian reserve, but the underlying mechanisms are not fully explored. Conclusions Direct tissue hypoxia led to premature activation and initiation of growth in dormant follicles leading to diminished ovarian reserve. Hypoxic damage is age-dependent, with adult ovaries more susceptible than newborn ovaries. These findings support the possibility of follicular "burn out" as a potential mechanism responsible for hypoxia-induced loss of ovarian reserve.

COVID-19 quarantine and sexual function after first vaginal delivery

Objectives Sexual function is an important part of quality of life at all ages. Childbirth brings many changes that may affect sexual function. During quarantine due to the COVID-19 global pandemic, nuclear families were forced to stay home. The goal of this study was compere sexual function prior to the COVID-19 quarantine and during the quarantine, in postpartum couples in the first months following their first vaginal childbirth. Design This is a single-center, prospective study of females following their first vaginal delivery and their male partners. The study included couples recruited from October 2019 until February 2020. Participants Participants were interviewed by telephone during the last week of the first COVID19 quarantine, according to Arizona Sexual Experience Scale (ASEX). Main outcome measures: Pre- and post-quarantine sexual function according to ASEX scores. ASEX is a survey that assesses sexual drive, arousal, vaginal lubrication, the ability to reach orgasm, and satisfaction from orgasm. Responses are scored on a 1-6 Likert scale with a potential range of 5-30, where the highest scores indicate worse sexual function. Results The participants were 38 women and 29 men. The average time from delivery to the interviews was 182.8± 84.7 days; 56% of the spouses were under quarantine. The median baseline total ASEX score was 13 (sexual drive 3, arousal 2.5, vaginal lubrication 2.5, ability to reach orgasm 2, orgasm satisfaction 2) for women; and 11 (sexual drive 3, arousal 2, penile erection 1, ability to reach orgasm 2, orgasm satisfaction 2) for men. Sixteen percent of the women and none of the men had a baseline sexual dysfunction (ASEX score >19). Significant differences were not observed in total ASEX scores before and during the quarantine. Limitations Sexual function at the end of the quarantine was evaluated prospectively and pre-quarantine sexual function was evaluated retrospectively, with the limitation of recall bias. Conclusions COVID-19 quarantine did not seem to have a significant effect on female or male sexual function, three to nine months after the first vaginal delivery. The current study is the first to discride primiparous postpartum sexual function as median ASEX score.

Maternal N-Acetyl-Cysteine Prevents Neonatal Hypoxia-Induced Brain Injury in a Rat Model

Perinatal hypoxia is a major cause of infant brain damage, lifelong neurological disability, and infant mortality. N-Acetyl-Cysteine (NAC) is a powerful antioxidant that acts directly as a scavenger of free radicals. We hypothesized that maternal-antenatal and offspring-postnatal NAC can protect offspring brains from hypoxic brain damage.Sixty six newborn rats were randomized into four study groups. Group 1: Control (CON) received no hypoxic intervention. Group 2: Hypoxia (HYP)-received hypoxia protocol. Group 3: Hypoxia-NAC (HYP-NAC). received hypoxia protocol and treated with NAC following each hypoxia episode. Group 4: NAC Hypoxia (NAC-HYP) treated with NAC during pregnancy, pups subject to hypoxia protocol. Each group was evaluated for: neurological function (Righting reflex), serum proinflammatory IL-6 protein levels (ELISA), brain protein levels: NF-κB p65, neuronal nitric oxide synthase (nNOS), TNF-α, and IL-6 (Western blot) and neuronal apoptosis (histology evaluation with TUNEL stain). Hypoxia significantly increased pups brain protein levels compared to controls. NAC administration to dams or offspring demonstrated lower brain NF-κB p65, nNOS, TNF-α and IL-6 protein levels compared to hypoxia alone. Hypoxia significantly increased brain apoptosis as evidenced by higher grade of brain TUNEL reaction. NAC administration to dams or offspring significantly reduce this effect. Hypoxia induced acute sensorimotor dysfunction. NAC treatment to dams significantly attenuated hypoxia-induced acute sensorimotor dysfunction. Prophylactic NAC treatment of dams during pregnancy confers long-term protection to offspring with hypoxia associated brain injury, measured by several pathways of injury and correlated markers with pathology and behavior. This implies we may consider prophylactic NAC treatment for patients at risk for hypoxia during labor.

Optimizing cervical ripening in women presenting with decreased fetal movements

OBJECTIVE

To determine the optimal method for cervical ripening in women presenting with decreased fetal movements at term. We hypothesized that women who undergo induction of labor for decreased fetal movements represent a higher risk group, and will benefit from mechanical intervention with cervical ripening balloon rather than with pharmacological prostaglandin E2 vaginal insert.

STUDY DESIGN

Retrospective cohort study from January 2014 and January 2019. We recommended induction of labor to every woman ≥39 weeks' gestation with complaints of persistent decreased fetal movements. We excluded women with major fetal anomalies, Bishop score of ≥6 on admission, and cases with contraindications to prostaglandins. Women were allocated into one of two groups based on the cervical ripening agent used. In group 1 we introduced the prostaglandin E2 vaginal insert (10 mg dinoprostone in a timed-release formulation). In group 2 we placed the mechanical cervical ripening balloon. The primary outcome of the study, analyzed separately to nulliparous and multiparous women, was the rate of cesarean delivery in each of the groups.

RESULTS

During the 5-years study, 294 women were included in the final analysis, of which 201 were in the prostaglandin E2 vaginal insert group and 93 were in the cervical ripening balloon group. The rate of cesarean delivery was comparable between the groups (nulliparous: 20.8%, 16/77 versus 21.3%, 10/47. multiparous: 16.9%, 21/124 versus 7%, 3/46, respectively). Other maternal and neonatal secondary outcomes, including the induction-to-delivery time (nulliparous: 32.5 ± 25.3 h versus 26.5 ± 12.2 h. multiparous: 24.6 ± 17.2 h versus 21.25 ± 12.3 h, respectively), were also not different between the two induction methods used. A longer induction-to-delivery time was observed in nulliparous women who had repeat prostaglandin E2 vaginal insert compared with the cervical ripening balloon group (74.6 ± 27.3 h versus 26.5 ± 12.2 h, p < .01).

CONCLUSION

Both pharmacological and mechanical methods can safely and efficiently be used for cervical ripening in women presenting with decreased fetal movements at term. With repeat prostaglandin E2 use, nulliparous women may experience a prolong labor compared with the cervical ripening balloon group, but maternal or fetal safety are not compromised.

Perinatal hypoxia leads to primordial follicle activation and premature depletion of ovarian reserve

BACKGROUND

The human ovary contains 6-million follicles during the 20th week of embryonic development and 1 million at birth. Girls born at small for gestational age weight demonstrate higher FSH levels during infancy, an earlier onset of puberty, and menarche. In light of these observations, we hypothesized that exposure to hypoxia at the early neonatal period might impact the primordial follicular pool and lead to premature depletion of ovarian reserve.

METHODS

Ovarian development in the rat model at days 1-5 postpartum reflects its human counterpart in the late perinatal period. We exposed newborn rat pups (n = 5) to controlled hypoxia, (5% oxygen/95% nitrogen) for 10 min three times daily for days 1-5 postpartum. On day 5, ovaries were harvested, H&E, Ki-67, and TUNEL staining were performed.

RESULTS

The percentage of primordial follicles out of total follicles in ovaries of pups exposed to hypoxia was lower compared to control (76 ± 8.2% and 90.33 ± 6.3% respectively, p < .05). Correspondingly the percentage of primary and secondary follicles was higher than in control. The mean stromal Ki67 staining score was significantly lower in the study group (1.67 ± 0.58 and 2.5 ± 0.55 respectively, p < .05). TUNEL staining demonstrated no difference in stromal apoptosis rates between both groups.

CONCLUSIONS

We provide evidence for the first time that perinatal hypoxia causes premature activation and growth initiation of dormant follicles. These changes were associated with decreased stromal cell proliferation, suggesting hypoxia-induced impairment of the support cell pool as a possible mechanism for accelerated follicular activation.

Progesterone Attenuates Brain Inflammatory Response and Inflammation-Induced Increase in Immature Myeloid Cells in a Mouse Model

Progesterone has been shown to regulate immunity during pregnancy, and progesterone administration may reduce inflammation-induced preterm labor. We sought to determine the maternal brain immune response to LPS-induced inflammation in pregnant and non-pregnant mice and whether additional progesterone supplementation attenuates this response. Pregnant (P: n = 9) and non-pregnant mice (NP: n = 9) were randomized to pretreatment with vaginal progesterone/carrier (Replens), daily from days 13 to 16. On days 15 and 16, LPS/saline was administered by intraperitoneal injection (Replens + saline n = 3; Replens + LPS n = 3; progesterone + LPS n = 3). Mice were sacrificed on day 16 and maternal serum analyzed for IL-6 levels and brains analyzed for nNOS, NF-kB, IL-6 protein levels and for immature myeloid cells (IMCs) and microglial activity. LPS significantly increased brain nNOS, NF-kB, and IL-6 in both NP and P mice, with significantly greater responses in P mice. In both NP and P groups, progesterone significantly attenuated LPS-induced increase of nNOS and NF-kB, however with no effect on serum IL-6. In the NP brains, LPS significantly increased IMC population and progesterone reduced the IMC phenotype to levels similar to controls. In P mice, neither LPS nor LPS + progesterone altered the brain IMC population. LPS significantly increased the microglial activity in both NP and P groups, which was attenuated by progesterone. Progesterone attenuates brain inflammatory response to LPS in both NP and P mice although it has no effect on systemic inflammation. In NP mice, progesterone attenuated the increase in brain IMC following LPS administration. Our results suggest that endogenous progesterone during pregnancy may protect the brain from LPS-induced inflammation.