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

Abstract

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.

Keywords: artificial reproductive techniques; dydrogesterone; early pregnancy; luteal-phase support; progeny; reproductive disorders; safety; tolerability.

Figure 1

Dydrogesterone (DG) treatment induced a short-term increase in implantation sizes at GD10, but did not alter placental and fetal parameters at GD12. Pregnant females were injected with 0.1% ethanol (n = 8), 2 mg/kg DG (n = 9), or 6 mg/kg DG (n = 9) from GD0–GD10. The graphics show (A) implantation areas, (B) placental areas, (C) ratio of placental diameter to placental thickness, (D) total number of implantation, (E) abortion rate, (F) placental weight, (G) fetal weight, and (H) placental index. Data are shown as means plus S.D. and were analyzed for statistical differences either by using one-way ANOVA followed by Tukey’s multiple comparison test or by applying a mixed linear model using the final test principal. ** p < 0.01 vs. control.

Figure 2

Dydrogesterone (DG) treatment had no influence on maternal- and fetal-placental blood-flow parameters in the postimplantation period. Pregnant females were injected with 0.1% ethanol (n = 8), 2 mg/kg DG (n = 9), or 6 mg/kg DG (n = 9) from GD0–GD10. Graphics and figures show (A) location of the uterine artery and corresponding Doppler flow diagram, (B) resistance index of the uterine artery, (C) pulsatility index of the uterine artery, (D) location of the umbilical artery and corresponding Doppler flow diagram, (E) resistance index of the umbilical artery, and (F) pulsatility index of the umbilical artery. Data are shown as means plus S.D. and were analyzed for statistical differences by using one-way ANOVA followed by Tukey’s multiple comparison test or by applying a mixed linear model using the final test principal. RI—resistance index, PI –pulsatility index, PSV—peak systolic velocity, EDV—end-diastolic velocity, UA—uterine artery, UmA—umbilical artery.

Figure 3

Dydrogesterone (DG) treatment of pregnant dams shifted progeny’s sex ratio, affected the weight of female progeny, and impaired sperm quality and quantity of male progeny. Pregnant dams were injected with 0.1% ethanol (n = 8), 2 mg/kg DG (n = 8), or 6 mg/kg DG (n = 8) from GD0–GD10. Graphics and table show (A) ratio of female to male progeny, (B) number of all progeny, (C) total number of all progeny, (D) female progeny weight, (E) male progeny weight, (F) female fertility parameters, and (G) male fertility parameters. Data are shown as means plus S.D. and were analyzed for statistical differences by using one-way ANOVA followed by Tukey’s multiple comparison test, by applying a mixed linear model using the final test principal, or by using the chi square test. * p < 0.05 vs. 6 mg/kg DG and control (body weight).

Figure 4

Dydrogesterone (DG) treatment of pregnant dams did not provoke any changes in placental and fetal parameters or in fetal survival in subsequent pregnancies of female progeny. Pregnant dams were injected with 0.1% ethanol (n = 18), 2 mg/kg DG (n = 11), or 6 mg/kg DG (n = 21) from GD0–GD10. The graphics show (A) implantation areas, (B) placental areas, (C) ratio of placental diameter to placental thickness, (D) total number of implantation, (E) abortion rate, (F) placental weight, (G) fetal weight, and (H) placental index. Data are shown as means plus S.D. and were analyzed for statistical differences either by using one-way ANOVA followed by Tukey’s multiple comparison test or by applying a mixed linear model using the final test principal. ** p < 0.01 vs. 2 mg/kg DG.

Figure 5

Dydrogesterone (DG) treatment of pregnant dams did not influence maternal- and fetal-placental blood-flow parameters in pregnant female progeny. Pregnant dams were injected with 0.1% ethanol (n = 8), 2 mg/kg DG (n = 8), or 6 mg/kg DG (n = 8) from GD0–GD10. Graphics and figures show (A) location of the uterine artery and corresponding Doppler flow diagram, (B) resistance index of the uterine artery, (C) pulsatility index of the uterine artery, (D) location of the umbilical artery and corresponding Doppler flow diagram, (E) resistance index of the umbilical artery, and (F) pulsatility index of the umbilical artery. Data are shown as means plus S.D. and were analyzed for statistical differences by using one-way ANOVA followed by Tukey’s multiple comparison test or by applying a mixed linear model using the final test principal. RI—resistance index, PI—pulsatility index, PSV—peak systolic velocity, EDV—end-diastolic velocity, UA—uterine artery, UmA—umbilical artery.