Effects and mechanisms of intrauterine chronic hypoxia on ovarian reserve function of zygotic rats

Chronic intrauterine hypoxia (ICH) may lead to permanent alterations in the offspring's body structure, function, and metabolism through the "developmental programming" pathway, resulting in lasting changes in physiology and metabolism, as well as the onset of adult-onset diseases. The aim was to investigate intrauterine growth restriction caused by ICH and its effect on ovarian reserve function in female offspring at different developmental stages after birth. Healthy female Sprague–Dawley rats (n = 20) were pregnant by normal mating, and the rats in the ICH group were treated with chronic intrauterine hypoxia twice a day for 04 h00 each time from day 4 to 21 of gestation. After the first hypoxic treatment, four pregnant rats were randomly selected from the ICH and natural control groups for arterial blood gas analysis. In the ICH group, birth weight and body weight on the 5th day after birth were less than in the control group, the total number of follicles and the number of primordial follicles in the offspring of the ICH group were significantly reduced on postnatal days 5, 20, and 40 (p < 0.05). ICH decreases ovarian reserve function in female offspring rats and programmatically regulates the differential expression of ovarian miRNAs in female offspring rats.