Csapo, A. I., Pulkkinen, M. O., Ruttner, B., Sauvage, J. P., & Wiest, W. G. (1972). The significance of the human corpus luteum in pregnancy maintenance. I. Preliminary studies. American Journal of Obstetrics and Gynecology, 112(8), 1061-1067. https://doi.org/10.1016/0002-9378(72)90181-0
Csapo AI, Pulkkinen MO, Ruttner B, Sauvage JP, Wiest WG. The significance of the human corpus luteum in pregnancy maintenance. I. Preliminary studies. Am J Obstet Gynecol. 1972;112(8):1061-1067. doi:10.1016/0002-9378(72)90181-0
Csapo, A. I., et al. "The significance of the human corpus luteum in pregnancy maintenance. I. Preliminary studies." American Journal of Obstetrics and Gynecology, vol. 112, no. 8, 1972, pp. 1061-1067.
Removing a large corpus luteum at day 49 was followed by abortion
A 1972 series of 12 first-trimester patients reported that removing a large corpus luteum around day 49 was followed by abortion, but removing a smaller one around day 61 was not. Progesterone continued to fall after removal around day 49 but fell only briefly after removal around day 61.
Key Findings
Twelve first-trimester pregnant patients were studied: 3 had ovariectomy for ovarian cysts, and 9 had luteectomy during tubal ligation.
In 7 patients, corpora lutea averaging 21 plus or minus 1mm were removed at Day 49 plus or minus 2; abortion followed a mean of 5 plus or minus 1 days later.
Five patients had corpora lutea averaging 11 plus or minus 1mm, removed at Day 61 plus or minus 4. Progesterone fell only briefly and then rose, and abortion did not follow.
The authors write that it appears the corpus luteum is indispensable while it is the major source of progesterone, and dispensable after the luteoplacental shift to the placenta.
Interpretation
The report is a small clinical series of 12 patients. Researchers followed progesterone, intrauterine pressure, oxytocin response and cervical dilatation after the luteal tissue was removed. The abstract presents the two groups with different operation timing and corpus luteum size. This synopsis draws on that abstract of the preliminary report, so full methods are not summarized.
RRM Context
This series examines progesterone from the corpus luteum in early pregnancy. Restorative reproductive medicine treats the luteal phase as worth examining. NaProTechnology does this with cycle-timed assessment.
Our editorial summary of this paper, not the article's abstract.
Abstract
Following the total removal of luteal tissue, circulating plasma progesterone, intrauterine pressure, oxytocin response, and clinical progress in abortion were determined sequentially in 12 first-trimester pregnant patients. 3 patients were ovariectomized for the removal of ovarian cysts and 9 were luteectomized during tubal ligation in an attempt to terminate pregnancy in spontaneous abortion. 7 patients had corpora lutea which averaged 21 plus or minus 1mm in diameter at operation when performed at Day 49 plus or minus 2 (mean S.E.) of pregnancy. These patients responded to ovariectomy or luteectomy by a continuing decrease in progesterone, evolution in intrauterine pressure, oxytocin response, progress in cervical dilitation and, abortion. Abortion occurred with a mean lapse time of 5 plus or minus 1 days after operation. In contrast, 5 patients whose corpora lutea averaged only 11 plus or minus 1mm in diameter when removed at Day 61 plus or minus 4 of pregnancy showed only transient decrease in progesterone after operation. This decrease was followed by an increase in progesterone; no progress in the evolution of intrauterine pressure, oxytocin response, cervical dilatation, and abortion. It appears that so long as the corpus luteum serves as the major source of progesterone, it is indispensable in the maintenance of pregnancy in human subjects as it is in the clinical model animal, the rabbit. However, with the shift of progesterone production from the corpus luteum to the placenta (the luteoplacental shift) the human corpus luteum becomes dispensable. These findings identify the corpus luteum and its secretory product, progesterone, as feasible targets of fertility control strategy.
