Atypical Intrapartum Maternal Heart Rate Pattern in a Woman with Paroxysmal Supraventricular Tachycardia

Pregnant women show characteristic hemodynamics, and their heart rates ordinarily increase with uterine contractions during labor. Conversely, uterine contraction-associated decelerations of maternal heart rate (MHR) are rare. We present a pregnant woman with paroxysmal supraventricular tachycardia (PSVT) who exhibited intrapartum MHR deceleration pattern. We performed simultaneous fetal heart rate monitoring with an external ultrasound transducer and MHR monitoring with a tocogram during her parturition. She developed a PSVT exacerbation in the second stage of parturition. As revealed by cardiotocography, the MHR baseline abruptly declined at onset of uterine contractions during the active phase of labor. Recovery followed, and the contraction resolved. The tachycardia got prolonged as the labor advanced. Our patient exhibited the unusual, up-and-down changes of the MHR pattern associated with labor contractions. The etiology of the occurrence of uterine contraction-associated MHR decelerations was unclear in the present case. Continuous tracing to visually inspect MHR patterns during parturition is a simple method for examining real-time MHR status of patients treated within obstetric practice settings.

Ge-Gen Decoction attenuates oxytocin-induced uterine contraction and writhing response: potential application in primary dysmenorrhea therapy

The uterine tetanic contraction and uterine artery blood flow reduction are possible reasons for primary dysmenorrhea(PD). In the present study, we aimed to evaluate the uterine relaxant effect and the influence on uterine artery blood velocity of Ge-Gen Decoction(GGD), a well-known Chinese herbal formula. In female ICR mice, uterine contraction was induced by oxytocin exposure following estradiol benzoate pretreatment, and the uterine artery blood velocity was detected by Doppler ultrasound. Histopathological examination of the uterine tissue samples were performed by H&E staining. Ex vivo studies demonstrated that oxytocin, posterior pituitary, or acetylcholine induced contractions in isolated mouse uterus. GGD inhibited both spontaneous and stimulated contractions. In vivo study demonstrated that GGD significantly reduced oxytocin-induced writhing responses with a maximal inhibition of 87%. Further study demonstrated that GGD normalized oxytocin-induced abnormalities of prostaglandins F_2 alpha(PGF_(2α)) and Ca^(2+) in mice. In addition, injection of oxytocin induced a decrease in uterine artery blood flow velocity. Pretreatment with GGD reversed the oxytocin response on blood flow velocity. Histopathological examination showed pretreatment with GGD alleviated inflammation and edema in the uterus when compared with the model group. Both ex vivo and in vivo results indicated that GGD possessed a significant spasmolytic effect on uterine tetanic contraction as well as improvement on uterine artery blood velocity which may involve PGF_(2α) and Ca^(2+) signaling, suggesting that GGD may have a clinic potential in PD therapy.

Effect of Acupoint Sanyinjiao(SP6) Moxibustion on the First Stage of Labor and Uterine Contractive Pain in Primiparae

Objective：To observe the effect of acupoint Sanyinjiao（SP6） moxibustion（S-Mox） on the duration of the first labor stage and uterine contractive pain in primiparae.Methods：Sixty primipara women in labor were equally assigned according to their choice to three groups：women in the S-Mox group received bilateral S-Mox for 30 min,women in the non-acupoint group received moxibustion（Mox） applied on non-acupoints for 30 min,and those in the control group did not receive Mox intervention.The duration of the first labor stage was recorded and the degree of labor pain was estimated by a visual analogue scale（VAS） before and after Mox. Results：The duration of the first stage active phase in the S-Mox group was significantly shorter than that in the other two groups（P0.05,P0.01）;the VAS score after Mox was lower in the S-Mox group,showing a statistical difference in comparison with the control group（P0.05）.Conclusions：Applying S-Mox could markedly shorten the active phase of the first stage of labor and lower the VAS score of uterine contractive pain,which means alleviating the pain caused by vaginal delivery.Its mechanism is worthy of further study.

Expression of Potassium Channels in Uterine Smooth Muscle Cells from Patients with Adenomyosis

Background： Adenomyosis （AM） has impaired contraction. This study aimed to explore the expression of potassium channels related to contraction in myometrial smooth muscle cells （MSMCs） of AM. Methods： Uterine tissue samples from 22 patients （cases） with histologically confirmed AM and 12 （controls） with cervical intraepithelial neoplasia were collected for both immunohistochemistry and real-time polymerase chain reaction to detect the expression of large conductance calciumand voltage-sensitive K＋ channel （BKCa）-a/β subunits, voltage-gated potassium channel （Kv） 4.2, and Kv4.3. Student＇s t-test was used to compare the expression. Results： The BKCa-a/β subunits, Kv4.2, and Kv4.3 were located in smooth muscle cells, glandular epithelium, and stromal cells. However, BKCa-β subunit expression in endometrial glands of the controls was weak, and Kv4.3 was almost undetectable in the controls. The expression of BKCa-a messenger RNA （mRNA） （0.62 ± 0.19-fold decrease, P 〈 0.05） and Kv4.3 mRNA （0.67 ±0.20-fold decrease, P 〈 0.05） decreased significantly in the MSMCs of the control group compared with the AM group. However, there were no significant differences in BKCa-β subunit mRNA or Kv4.2 mRNA. Conclusions： The BKCa-a mRNA and the Kv4.3 mRNA are expressed significantly higher in AM than those in the control group, that might cause the abnormal uterus smooth muscle contractility, change the microcirculation of uterus to accumulate the inflammatory factors, impair the endometrium further, and aggravate the pain.

Ggps1 deficiency in the uterus results in dystocia by disrupting uterine contraction

Dystocia is a serious problem for pregnant women, and it increases the cesarean section rate. Although uterine dysfunction has an unknown etiology, it is responsible for cesarean delivery and clinical dystocia, resulting in neonatal morbidity and mortality;thus, there is an urgent need for novel therapeutic agents. Previous studies indicated that statins, which inhibit the mevalonate (MVA) pathway of cholesterol synthesis, can reduce the incidence of preterm birth, but the safety of statins for pregnant women has not been thoroughly evaluated. Therefore, to unambiguously examine the function of the MVA pathway in pregnancy and delivery, we employed a genetic approach by using myometrial cell-specific deletion of geranylgeranyl pyrophosphate synthase (Ggps1) mice. We found that Ggps1 deficiency in myometrial cells caused impaired uterine contractions, resulting in disrupted embryonic placing and dystocia. Studies of the underlying mechanism suggested that Ggps1 is required for uterine contractions to ensure successful parturition by regulating RhoA prenylation to activate the RhoA/Rock2/p-MLC pathway. Our work indicates that perturbing the MVA pathway might result in problems during delivery for pregnant females, but modifying protein prenylation with supplementary farnesyl pyrophosphate or geranylgeranyl pyrophosphate might be a strategy to avoid side effects.