Early-Pregnancy Dydrogesterone Supplementation Mimicking Luteal-Phase Support in ART Patients Did Not Provoke Major Reproductive Disorders in Pregnant Mice and Their Progeny.

Progestogens are frequently administered during early pregnancy to patients undergoing assisted reproductive techniques (ART) to overcome progesterone deficits following ART procedures. Orally administered dydrogesterone (DG) shows equal efficacy to other progestogens with a higher level of patient compliance. However, potential harmful effects of DG on critical pregnancy processes and on the health of the progeny are not yet completely ruled out. We treated pregnant mice with DG in the mode, duration, and doses comparable to ART patients. Subsequently, we studied DG effects on embryo implantation, placental and fetal growth, fetal-maternal circulation, fetal survival, and the uterine immune status. After birth of in utero DG-exposed progeny, we assessed their sex ratios, weight gain, and reproductive performance. Early-pregnancy DG administration did not interfere with placental and fetal development, fetal-maternal circulation, or fetal survival, and provoked only minor changes in the uterine immune compartment. DG-exposed offspring grew normally, were fertile, and showed no reproductive abnormalities with the exception of an altered spermiogram in male progeny. Notably, DG shifted the sex ratio in favor of female progeny. Even though our data may be reassuring for the use of DG in ART patients, the detrimental effects on spermatogenesis in mice warrants further investigations and may be a reason for caution for routine DG supplementation in early pregnancy.

Dermal exposure to the UV filter benzophenone-3 during early pregnancy affects fetal growth and sex ratio of the progeny in mice.

The aim of this study was to analyze whether dermal exposure to benzophenone 3 (BP-3) during pregnancy affects critical parameters of pregnancy, and whether this exposure may affect the outcome of a second pregnancy in mice. Pregnant mice were exposed to 50-mg BP-3/kg body weight/day or olive oil (vehicle) from gestation day (gd) 0 to gd6 by dermal exposure. High-frequency ultrasound imaging was used to follow up fetal and placental growth in vivo. Blood flow parameters in uterine and umbilical arteries were analyzed by Doppler measurements. Mice were killed at gd5, gd10, and gd14 on the first pregnancy, and at gd10 and 14 on the second pregnancy. The weight of the first and second progenies was recorded, and sex ratio was analyzed. BP-3 levels were analyzed in serum and amniotic fluid. BP-3 reduced the fetal weight at gd14 and feto-placenta index of first pregnancy, with 16.13% of fetuses under the 5th percentile; arteria uterina parameters showed altered pattern at gd10. BP-3 was detected in serum 4 h after the exposure at gd6, and in amniotic fluid at gd14. Offspring weight of first progeny was lower in BP-3 group. Placenta weights of BP-3 group were decreased in second pregnancy. First and second progenies of mothers exposed to BP-3 showed a higher percentage of females (female sex ratio). Dermal exposure to low dose of BP-3 during early pregnancy resulted in an intrauterine growth restriction (IUGR) phenotype, disturbed sex ratio and alterations in the growth curve of the offspring in mouse model.

Culturing Rat Whole Ovary for UV Filter Benzophenone-3 Treatment.

We describe a detailed protocol to establish a newborn rat whole ovary culture, which enables the study of direct effects (independent of hypothalamic-pituitary-gonadal axis) of endocrine disrupting chemicals (EDCs), such as benzophenone-3 (BP-3). This method is useful to understand changes in follicle formation, primordial to primary transition, and expression of regulatory molecules linked to these processes and also provides an alternative to animal models. © 2019 by John Wiley & Sons, Inc. Basic Protocol 1: Rat ovarian surgery Basic Protocol 2: Whole organ/ovarian culture Basic Protocol 3: RNA isolation and quantitative real-time PCR Basic Protocol 4: Histological processing and staining.

Exposure to 17α-ethinyl estradiol during early pregnancy affects fetal growth and survival in mice.

17α-ethinyl estradiol (EE2) is a synthetic compound widely used in the generation of contraceptive pills. EE2 is present in the urine of women taking contraceptives and its presence has been confirmed at increasing concentrations contaminating rivers all over the world. Because of this cycle, it can entry the human food chain when watering plants. A negative influence of EE2 on fertility and reproductive capacity of wildlife was already suggested. The short-term impact of exposure to contaminating EE2 on pregnancy outcome has not been addressed. Pregnant mice were exposed to either 0.005 µg (concentrations found in water) or 5 µg EE2/kg (contraceptive dose) body weight/day from gestation day 1-7 by oral gavage. Control mice received a 0.1% ethanol solution. High frequency ultrasound imaging was used to follow-up fetal and placental growth in vivo. Doppler measurements were utilized to analyze blood flow parameters in uterine and umbilical arteries. Mice were sacrificed at gd5, 10, and 14. We show that most fetuses of mothers exposed to the high EE2 dose die intrauterine at gd10, with implantation sizes beginning to be smaller already at gd8. Mothers exposed to the low EE2 dose show an impaired remodeling of the spiral arteries, a higher placental weight and pups that are large for gestational age. The insulin-like growth factor system that regulates fetal and placental growth and development is affected by the EE2 treatment. Our results show that a short-term exposure to EE2 during early pregnancy has severe consequences for fetal growth and survival depending on the dose. Exposition to synthetic estrogens affects placenta growth and angiogenesis. These findings urge to the study of mechanisms dysregulated upon environmental exposition to estrogens.

Bisphenol A exposure during early pregnancy impairs uterine spiral artery remodeling and provokes intrauterine growth restriction in mice.

Endocrine disrupting chemicals are long suspected to impair reproductive health. Bisphenol A (BPA) has estrogenic activity and therefore the capacity of interfering with endocrine pathways. No studies dissected its short-term effects on pregnancy and possible underlying mechanisms. Here, we studied how BPA exposure around implantation affects pregnancy, particularly concentrating on placentation and uterine remodeling. We exposed pregnant female mice to 50 µg/kg BPA/day or 0.1% ethanol by oral gavage from day 1 to 7 of gestation. High frequency ultrasound was employed to document the presence and size of implantations, placentas and fetuses throughout pregnancy. Blood velocity in the arteria uterina was analyzed by Doppler measurements. The progeny of mothers exposed to BPA was growth-restricted compared to the controls; this was evident in vivo as early as at day 12 as analyzed by ultrasound and confirmed by diminished fetal and placenta weights observed after sacrificing the animals at day 14 of gestation. The remodeling of uterine spiral arteries (SAs) was considerably impaired. We show that short-term exposure to a so-called "safe" BPA dose around implantation has severe consequences. The intrauterine growth restriction observed in more than half of the fetuses from BPA-treated mothers may owe to the direct negative effect of BPA on the remodeling of uterine SAs that limits the blood supply to the fetus. Our work reveals unsuspected short-term effects of BPA on pregnancy and urges to more studies dissecting the mechanisms behind the negative actions of BPA during early pregnancy.