Effect of endogenous steroid hormones on 17-alpha-hydroxyprogesterone caproate metabolism.

OBJECTIVE: Plasma concentrations of 17-alpha-hydroxyprogesterone caproate (17-OHPC) vary substantially in pregnant patients who receive an identical dose. Endogenous steroid hormones may alter 17-OHPC metabolism, which contributes to this large variability. STUDY DESIGN: Pooled human liver microsomes were incubated with 17-OHPC alone or in combination with progesterone, hydroxyprogesterone, estrone, estradiol, or estriol. High-performance liquid chromatography with ultraviolet detection was used to quantify 17-OHPC. RESULTS: Under the conditions that were studied, 17-OHPC metabolism was inhibited by 37% by a combination of endogenous steroid hormones. Progesterone alone significantly inhibited 17-OHPC metabolism by 28% (P < .001). CONCLUSION: 17-OHPC metabolism is inhibited significantly by endogenous steroids and, in particular, progesterone. This effect may account for some of the large variation in plasma 17-OHPC concentrations that is seen in pregnant patients who receive a fixed dose of medication.

Unruptured 32-week rudimentary horn pregnancy presenting as right upper quadrant pain.

BACKGROUND: An unruptured third trimester rudimentary horn pregnancy is rare, life threatening, and can go undetected until the onset of symptoms. Given the high risk of uterine rupture, conservative management after viability is controversial. CASE: A 21 year-old with a 32-week rudimentary horn pregnancy, diagnosed via exploratory laparotomy five days earlier, presented with acute right upper quadrant pain. The patient underwent cesarean delivery. The rudimentary horn was noted to be intact, but so thin it was transparent. CONCLUSION: Advanced ectopic pregnancy or rudimentary horn pregnancy should be considered in cases of unusual or undiagnosed abdominal pain in pregnancy. When surgical exploration is performed, an incision allowing optimal visualization and exposure is recommended.

Diagnosis and management of a monochorionic/monoamniotic twin gestation discordant for fetal anomalies.

Monoamniotic twinning is rare and associated with fetal mortality as high as 13-32% (1). In pregnancies discordant for fetal anomalies, mortality is as high as 43% (2.3). Currently, the optimal management and timing of delivery is not clearly defined. A 28-year-old presented with a monochorionic/monoamniotic twin gestation with unexplained ascites, ventriculomegaly, and pericardial effusion of Twin B. She was admitted at 24 weeks for intensive fetal surveillance and sulindac therapy. Planned Cesarean delivery was performed at 32 weeks gestation. A favorable neonatal outcome was achieved. Aggressive inpatient surveillance and intentional preterm delivery may result in favorable outcomes in monochorionic/monoamniotic twin gestations.