OBJECTIVE: Corticotropin-releasing hormone (CRH) is a crucial regulator of human pregnancy and parturition. Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels are important for regulating myometrial quiescence during pregnancy. We investigated regulatory effects of different concentrations of CRH on KATP channel expression in human myometrial smooth muscle cells (HSMCs) in in vitro conditions. METHODS: After treating HSMCs with different concentrations of CRH (1, 10, 102, 103, 104 pmol/L), mRNA and protein expression of KATP channel subunits (Kir6.1 and SUR2B) was analyzed by reverse transcription-polymerase chain reaction and western blot. We investigated which CRH receptor was involved in the reaction and measured the effects of CRH on intracellular Ca2+ concentration when oxytocin was administered in HSMCs using Fluo-8 AM ester. RESULTS: When HSMCs were treated with low (1 pmol/L) and high (103, 104 pmol/L) CRH concentrations, KATP channel expression significantly increased and decreased, respectively. SUR2B mRNA expression at low and high CRH concentrations was significantly antagonized by antalarmin (CRH receptor-1 antagonist) and astressin 2b (CRH receptor-2 antagonist), respectively; however, Kir6.1 mRNA expression was not affected. After oxytocin treatment, the intracellular Ca2+ concentration in CRH-treated HSMCs was significantly lowered in low concentration of CRH (1 pmol/L), but not in high concentration of CRH (103 pmol/L), compared to control. CONCLUSION: Our data demonstrated the regulatory effect was different when HSMCs were treated with low (early pregnancy-like) and high (labor-like) CRH concentrations and the KATP channel expression showed significant increase and decrease. This could cause inhibition and activation, respectively, of uterine muscle contraction, demonstrating opposite dual actions of CRH.
Adenosine Triphosphate ; Adenosine ; Animals ; Blotting, Western ; Corticotropin-Releasing Hormone ; Female ; Humans ; In Vitro Techniques ; KATP Channels ; Mice ; Myocytes, Smooth Muscle ; Myometrium ; Oxytocin ; Parturition ; Potassium Channels ; Potassium ; Pregnancy ; Receptors, Corticotropin-Releasing Hormone ; RNA, Messenger

Cesarean Section ; Cohort Studies ; Female ; Gestational Age ; Humans ; Mass Screening ; Parity ; Pregnancy ; Premature Birth ; Retrospective Studies ; Risk Factors ; Seoul ; Vacuum

Objective: We evaluated the incidence of newly diagnosed gestational diabetes mellitus (GDM) during the 3rd trimester in women with suspected large for gestational age (LGA) fetuses on ultrasound and assessed their perinatal outcomes. Methods: A retrospective cohort study was performed. Singleton pregnant women with suspected LGA on the 3rd trimester ultrasound and whose results of GDM screening at midpregnancy had been normal were enrolled. All participants were retested with 100-g oral glucose tolerance test (OGTT) within 2 days after diagnosis of LGA. We compared perinatal outcomes between the newly diagnosed with GDM group and the non-GDM group. Results: Among 169 pregnant women, 13% (23/169) were newly diagnosed with GDM. The women in the GDM group had a higher HbA1c level at diagnosis (5.8 vs. 5.3, P<0.01) and earlier gestational age at delivery (38.0 vs 38.9 weeks of gestation, P=0.003) than those in the non-GDM group. The rate of cesarean delivery (CD) was significantly higher in the GDM group than that in the non-GDM group (73.9%, vs. 49.3%, P=0.028) with similar proportions for the indications of CD except CD on maternal request (CDMR). The CDMR rate was higher in the GDM group than nonGDM group (41.2% vs. 23.6%) but it did not reach statistical significance. There were no significant differences in the obstetrical and neonatal complications between the two groups. Conclusion Among pregnant women with suspected LGA, 13% were newly diagnosed with GDM in late pregnancy. Nonetheless, there were no differences in the perinatal outcomes between women with newly diagnosed GDM and those without GDM. However, concerns over shoulder dystocia appear to increase CD rates in the GDM group.

Objective: We evaluated the incidence of newly diagnosed gestational diabetes mellitus (GDM) during the 3rd trimester in women with suspected large for gestational age (LGA) fetuses on ultrasound and assessed their perinatal outcomes. Methods: A retrospective cohort study was performed. Singleton pregnant women with suspected LGA on the 3rd trimester ultrasound and whose results of GDM screening at midpregnancy had been normal were enrolled. All participants were retested with 100-g oral glucose tolerance test (OGTT) within 2 days after diagnosis of LGA. We compared perinatal outcomes between the newly diagnosed with GDM group and the non-GDM group. Results: Among 169 pregnant women, 13% (23/169) were newly diagnosed with GDM. The women in the GDM group had a higher HbA1c level at diagnosis (5.8 vs. 5.3, P<0.01) and earlier gestational age at delivery (38.0 vs 38.9 weeks of gestation, P=0.003) than those in the non-GDM group. The rate of cesarean delivery (CD) was significantly higher in the GDM group than that in the non-GDM group (73.9%, vs. 49.3%, P=0.028) with similar proportions for the indications of CD except CD on maternal request (CDMR). The CDMR rate was higher in the GDM group than nonGDM group (41.2% vs. 23.6%) but it did not reach statistical significance. There were no significant differences in the obstetrical and neonatal complications between the two groups. Conclusion Among pregnant women with suspected LGA, 13% were newly diagnosed with GDM in late pregnancy. Nonetheless, there were no differences in the perinatal outcomes between women with newly diagnosed GDM and those without GDM. However, concerns over shoulder dystocia appear to increase CD rates in the GDM group.