Progesterone deficiency and premature labour.

Area of Science:

• Reproductive Endocrinology
• Maternal-Fetal Medicine
• Obstetrics

Background:

• Threatened premature labor is a significant concern in obstetrics, often with unknown etiology.
• Hormonal regulation, particularly progesterone's role in inhibiting uterine activity, is crucial for maintaining pregnancy.

Purpose of the Study:

• To investigate plasma hormone levels (estradiol and progesterone) in patients with threatened premature labor.
• To compare these levels with those in normal pregnancies at similar gestational stages.
• To explore the relationship between hormonal balance and uterine activity regulation.

Main Methods:

• Comparison of plasma estradiol 17beta and progesterone levels.
• Study group: 11 patients with threatened premature labor of unknown cause.
• Control group: Women with normal pregnancies at similar gestational ages.

Main Results:

• Patients with threatened premature labor showed slightly higher estradiol levels compared to normal controls.
• Significantly lower progesterone levels were observed in the threatened premature labor group.
• The estradiol/progesterone ratio was elevated in the study group, increasing further with progesterone withdrawal during labor.

Conclusions:

• Progesterone deficiency appears to create a regulatory imbalance, provoking premature labor.
• The uterine-volume/plasma-progesterone ratio is a more accurate indicator of regulatory balance than progesterone levels alone.
• The cause of progesterone deficiency is unclear, but placental factors may contribute; further research is needed to correct this imbalance.