Diabetes is associated with impairment of uterine contractility and high Caesarean section rate

Predictive Factors for Successful Cervical Ripening among Women with Gestational Diabetes Mellitus at Term: A Prospective Study

The purpose of this prospective cohort study is to identify the predictive factors for vaginal delivery among women (n = 146) who underwent cervical ripening using a dinoprostone insert (PG) alone (13.7%), cervical ripening balloon (CRB) alone (52.7%), oral misoprostol (M) alone (4.1%), or repeated methods (R, 29.5%) for gestational diabetes mellitus (GDM) at term, and to analyze maternal and neonatal morbidity outcomes according to the method for cervical ripening. After cervical ripening, vaginal delivery occurred in 84.2% (n = 123) and was similar among groups (90.0% after PG, 83.1% after CRB, 83.3% after M, and 83.7% after R; p = 0.89). After a multivariable logistic regression analysis adjusted for potential confounders, the internal cervical os being open before cervical ripening was a predictor of vaginal delivery (adjusted odds ratio (OR) of 4.38, 95% confidence index (CI) of 1.62-13.3, p = 0.03), and previous cesarean delivery was a predictor of cesarean delivery (aOR of 7.67, 95% CI of 2.49-24.00, p < 0.01). Birthweight was also significantly associated with cesarean delivery (aOR of 1.15, 95% CI of 1.03-1.31, p = 0.02). The rates of maternal and neonatal morbidity outcomes were 10.9% (n = 16) and 19.9% (n = 29), respectively, and did not differ according to the mode of delivery and to the method used for cervical ripening. Identifying these specific high-risk women (previous cesarean delivery and internal cervical os being closed before cervical ripening) for cesarean delivery among women who underwent cervical ripening for GDM at term is important and practical for all physicians to make a decision in partnership with women.

High glucose induced HIF-1α/TREK1 expression and myometrium relaxation during pregnancy

Background

The incidence of gestational diabetes mellitus (GDM) is increasing worldwide. GDM patients have a significantly higher rate of cesarean section and postpartum hemorrhage, suggesting changes in uterine contractility. TWIK-1-related potassium channel (TREK1) expressed in the pregnant uterus and its role in uterine contraction. In this study, we examined the expression of HIF-1α and TREK1 proteins in GDM uterine and investigated whether high glucose levels are involved in the regulation of human uterine smooth muscle cells (HUSMCs) contraction through TREK1, and verified the role of HIF-1α in this process.

Methods

Compared the uterine contractility between GDM and normal patients undergoing elective lower segment cesarean section. The HUSMCs were divided into normal glucose group, high glucose group, normal glucose with CoCl2 group, CoCl2 with echinomycin/L-Methionine group, and high glucose with echinomycin/L-Methionine group; Compare the cell contractility of each group. Compared the expression of hypoxia-inducible factor-1α (HIF-1α) and TREK1 protein in each group.

Results

The contractility of human uterine strips induced by both KCl and oxytocin was significantly lower in patients with GDM compared with that in normal individuals, with increased TREK1 and HIF-1α protein expression. The contractility of cultured HUSMCs was significantly decreased under high glucose levels, which was consistent with increased expression of HIF-1α and TREK1 proteins. The contractility of HUSMCs was decreased when hypoxia was induced by CoCl2 and increased when hypoxia was inhibited by echinomycin. The TREK1 inhibitor L-methionine also recovered the decreased contractility of HUSMCs under high glucose levels or hypoxia.

Discussion

The high glucose levels decreased the contractility of the myometrium, and increased expression of HIF-1a and TREK1 proteins play a role in changes in uterus contractility.

Cesarean delivery rates and indications in pregnancies complicated by diabetes

OBJECTIVE

Rates of pregestational (PGDM) and gestational diabetes (GDM), and their associated pregnancy complications, are rising. Pregnancies complicated by diabetes have increased cesarean delivery (CD) rates; however, there are limited data regarding the current rates of, and contributing factors to, these deliveries. The Robson Ten Group Classification System (TGCS) is a clinically relevant, standardized framework that can be used to evaluate and analyze cesarean rates. The objective of this study was to evaluate rates of, and indications for, intrapartum, unplanned CD among pregnancies complicated by diabetes, compared to normoglycemic (NG) pregnancies, in a large United States birth cohort.

METHODS

This retrospective cohort study used chart-abstracted data on births between 24 and 42 weeks' gestation at 17 hospitals that contributed to the Obstetrical Care Outcome Assessment Program database between 01/2016 and 03/2019. The CD rate for NG pregnancies, and pregnancies complicated by gestational and PGDM was calculated and compared using the Robson TGCS. The indications for intrapartum CD in patients with term, singleton, vertex gestations without a prior cesarean were then analyzed. Univariate and multivariate logistic regression models were used to compare the cesarean rate and indications for CD, between the diabetic groups and the NG group. Results were adjusted for maternal age, BMI, neonatal birth weight, and insurance status, as well as clustering by hospital.

RESULTS

A total of 86,381 pregnant people were included in the study cohort. Of these 76,272 (88.3%) were NG, 8591 (9.9%) had GDM, and 1518 (1.8%) had PGDM. Compared to NG patients, overall cesarean rates were higher in patients with GDM (40.3% vs. 29.7%; aOR 1.25, 95%CI 1.18-1.31) and PGDM (60.0% vs. 29.7%; aOR 2.53, 95%CI 2.04-3.13). This finding remained true when the cohort was restricted to term, singleton, vertex laboring patients without a prior cesarean; compared to NG patients, the cesarean rate was higher in patients with GDM (17.4% vs. 12.2%, aOR 1.37, 95%CI 1.29-1.45) and PGDM (26.0% vs. 12.2%, aOR 2.55, 95%CI 2.00-3.25). The cesarean rate for fetal indications was similar in the GDM (5.7%) and NG (4.4%) groups, while those patients with PGDM had a significantly higher rate (10.4%; aOR 2.01, 95%CI 1.43-2.83). Similarly, the rate of cesarean for labor dystocia in patients with PGDM was significantly higher than in NG patients (16.9% vs. 7.0%, and aOR 2.28, 95%CI 1.66-3.13) while patients with GDM had an intermediate rate (10.6% vs. 7.0%, aOR 1.49, 95%CI 1.40-1.57).

CONCLUSIONS

The CD rate is significantly higher in pregnancies complicated by diabetes, particularly pregestational, compared to NG pregnancies. Despite controlling for maternal factors and birth weight, pregnancies complicated by diabetes are more likely to undergo an unplanned intrapartum cesarean secondary to labor dystocia than their NG counterparts, but only pregnancies complicated by PGDM have an increased risk of cesarean for fetal indications. More research is needed to understand whether this higher cesarean rate is due to factors intrinsic to diabetes in laboring patients or is due to a difference in the way clinicians manage diabetics in labor.

Assisted reproduction technology outcomes in women with infertility and preexisting diabetes mellitus: a systematic review

OBJECTIVE

To assess maternal and neonatal outcomes in women with or without preexisting diabetes mellitus (DM) undergoing assisted reproduction technology (ART) treatment.

METHODS

Prospective or retrospective controlled trials reporting on women with or without preexisting DM undergoing ART treatment were considered eligible. Twelve electronic databases were systematically searched up to December 2020. The risk of bias was assessed by the Cochrane Risk OF Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Each primary outcome was extracted and pooled as maternal- or neonatal-related.

RESULTS

Two studies were included in the systematic review, reporting on both maternal- and neonatal-related parameters after ART treatment. Due to the limited data, no meta-analysis was conducted. Preterm birth, placenta previa, and excessive bleeding during pregnancy were observed more often in pregnancies complicated by preexisting DM conceived by ART compared with pregnancies without DM. There was no difference in the risk for placental abruption between the groups. Regarding the neonatal outcomes, large-for-gestational-age (LGA) embryos and neonatal intensive care unit (NICU) admission were more commonly reported for women with preexisting DM. In one study, preexisting DM was marginally associated with infant mortality.

CONCLUSIONS

Despite the scarce data, preexisting DM in pregnancies conceived by ART is associated with increased risk for maternal and neonatal complications.

TRIAL REGISTRATION

Registered in PROSPERO (registration number: 143187).

Gestational diabetes mellitus, pre-pregnancy body mass index and gestational weight gain predicts fetal growth and neonatal outcomes

BACKGROUND

Gestational diabetes mellitus (GDM), body mass index (BMI) and gestational weight gain (GWG) are salient predictors of pregnancy-outcomes. However, findings on the association between GDM, BMI, and GWG with fetal growth measures are limited.

OBJECTIVE

The aim of this study was to investigate the effect of GDM on fetal growth measures and birth outcomes.

METHODS

All participants came from Tongji Maternal and Child health cohort, in which pregnant women were enrolled before 16 weeks of gestation and had their weights measured regularly during antenatal visits. GDM was diagnosed by oral glucose tolerance test (OGTT) during 24-28 weeks of gestation. Ultrasound measurements of fetal bi-parietal diameters (BPD), head circumferences (HC), abdominal circumferences (AC) and femur length (FL) before birth were collected and neonate outcomes were obtained from the hospital records. Odds ratios were calculated using logistic regression to assess the association of GDM, pre-pregnancy BMI, and GWG with fetal growth measures of ultrasound and birth outcomes, while controlling confounding.

RESULTS

Of 3253 singleton pregnant women, 293 (9.0%) were diagnosed with GDM, 357 (11.0%) were overweight before pregnancy, and 1995 (61.3%) had excessive GWG. GDM was associated with decreased intrauterine fetal growth measurements including BPD and AC. Maternal pre-pregnancy overweight was associated with increased fetal HC and neonatal birth weight and length, women gained excessive GWG had increased fetal growth measurements of BPD, HC, AC, FL, neonatal birth weight and length. Offspring of GDM women had increased odds of cesarean section 1.31 (1.03, 1.66) and preterm birth 2.02 (1.05, 3.91) in unadjusted models, but these associations disappeared after adjustment. Compared with neonate born to mothers with normal pre-pregnancy weight, those born to underweight mother had higher risk of SGA, and lower risk of cesarean section, LGA and macrosamia, whereas those born to overweight mother had increased risk of cesarean section, LGA and macrosamia. Compared with neonate born to mothers of adequate GWG, neonate of women with excessive GWG had elevated risk of cesarean section, LGA and macrosamia, but lower risk of preterm birth and SGA.

CONCLUSION

Pre-pregnancy BMI, GWG and GDM all associated with fetal growth and birth outcomes. The effect of GDM decreased after adjusting pre-pregnancy BMI and GWG. Early screening and management of GDM, preventing excessive GWG could help protect fetuses of GDM mothers from adverse birth outcomes.

Influence of high glucose in the expression of miRNAs and IGF1R signaling pathway in human myometrial explants

PURPOSE

Several roles are attributed to the myometrium including sperm and embryo transport, menstrual discharge, control of uterine blood flow, and labor. Although being a target of diabetes complications, the influence of high glucose on this compartment has been poorly investigated. Both miRNAs and IGF1R are associated with diabetic complications in different tissues. Herein, we examined the effects of high glucose on the expression of miRNAs and IGF1R signaling pathway in the human myometrium.

METHODS

Human myometrial explants were cultivated for 48 h under either high or low glucose conditions. Thereafter, the conditioned medium was collected for biochemical analyses and the myometrial samples were processed for histological examination as well as miRNA and mRNA expression profiling by qPCR.

RESULTS

Myometrial structure and morphology were well preserved after 48 h of cultivation in both high and low glucose conditions. Levels of lactate, creatinine, LDH and estrogen in the supernatant were similar between groups. An explorative screening by qPCR arrays revealed that 6 out of 754 investigated miRNAs were differentially expressed in the high glucose group. Data validation by single qPCR assays confirmed diminished expression of miR-215-5p and miR-296-5p, and also revealed reduced miR-497-3p levels. Accordingly, mRNA levels of IGF1R and its downstream mediators FOXO3 and PDCD4, which are potentially targeted by miR-497-3p, were elevated under high glucose conditions. In contrast, mRNA expression of IGF1, PTEN, and GLUT1 was unchanged.

CONCLUSIONS

The human myometrium responds to short-term exposure (48 h) to high glucose concentrations by regulating the expression of miRNAs, IGF1R and its downstream targets.

Forces Involved with Labor and Delivery-A Biomechanical Perspective

Childbirth is a primarily biomechanical process of physiology, and one that engineers have recently begun to address in a broader fashion. Computational models are being developed to address the biomechanical effects of parturition on both maternal and fetal tissues. Experimental research is being conducted to understand how maternal tissues adapt to intrauterine forces near the onset of labor. All of this research requires an understanding of the forces that are developed through maternal efforts-both uterine contractions and semi-voluntary pushing-and that can be applied by the clinician to assist with the delivery. This work reviews the current state of knowledge regarding forces of labor and delivery, with a focus on macro-level biomechanics.

Fetal and Placental Weight in Pre-Gestational Maternal Obesity (PGMO) vs. Excessive Gestational Weight Gain (EGWG)-A Preliminary Approach to the Perinatal Outcomes in Diet-Controlled Gestational Diabetes Mellitus

Both pre-gestational maternal obesity (PGMO) and excessive gestational weight gain (EGWG) increase the risk of gestational diabetes mellitus (GDM). Here, we conducted a retrospective study to comparatively examine the relation between fetal birth weight (FW) and placental weight (PW) in PGMO (n = 100) compared to EGWG (n = 100) with respect to perinatal outcomes in diet-controlled GDM. The control group was made up of 100 healthy pregnancies. The mean FW and the mean PW in EGWG were correlated with lowered fetal weight/placental weight ratio (FW/PW ratio). The percentage of births completed by cesarean section accounted for 47%, 32%, and 18% of all deliveries (EGWG, PGMO, and controls, respectively), with the predominance of FW-related indications for cesarean section. Extended postpartum hospital stays due to neonate were more frequent in EGWG, especially due to neonatal jaundice (p < 0.05). The results indicate the higher perinatal risk in mothers with EGWG compared to PGMO during GDM-complicated pregnancy. Further in-depth comparative studies involving larger patient pools are needed to validate these findings, the intent of which is to formulate guidelines for GDM patients in respect to management of PGMO and EGWG.

Uterine Dysfunction in Diabetic Mice: The Role of Hydrogen Sulfide

It is well-known that the physiological uterine peristalsis, related to several phases of reproductive functions, plays a pivotal role in fertility and female reproductive health. Here, we have addressed the role of hydrogen sulfide (H₂S) signaling in changes of uterine contractions driven by diabetes in non-obese diabetic (NOD) mice, a murine model of type-1 diabetes mellitus. The isolated uterus of NOD mice showed a significant reduction in spontaneous motility coupled to a generalized hypo-contractility to uterotonic agents. The levels of cyclic nucleotides, cAMP and cGMP, notoriously involved in the regulation of uterus homeostasis, were significantly elevated in NOD mouse uteri. This increase was well-correlated with the higher levels of H₂S, a non-specific endogenous inhibitor of phosphodiesterases. The exposure of isolated uterus to L-cysteine (L-Cys), but not to sodium hydrogen sulfide, the exogenous source of H₂S, showed a weak tocolytic effect in the uterus of NOD mice. Western blot analysis revealed a reorganization of the enzymatic expression with an upregulation of 3-mercaptopyruvate-sulfurtransferase (3-MST) coupled to a reduction in both cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) expression. In conclusion, the increased levels of cyclic nucleotides dysregulate the uterus peristalsis and contractility in diabetic mice through an increase in basal H₂S synthesis suggesting a role of 3-MST.

PROGNOSTICATION LABOR DYSTOCIA AND CESAREAN SECTION

The article presents the results of the analysis of clinical and anamnestic indicators to create a model for predicting the development of labor dystocia that caused Caesarean section. The most significant prognostic factors included in the prognostic model were fetus-pelvic imbalances, diabetes mellitus, a burdened gynecological history and cardiovascular diseases in the nulliparous women of late reproductive age. Assessment of the totality of risk factors made it possible to achieve an accurate prognosis in 88.6% of cases with a sensitivity of 40.4%, specificity - 92.1%.

Association between insulin and post-caesarean resuscitation rates in infants of women with GDM: A retrospective study

BACKGROUND

Gestational diabetes mellitus (GDM) and caesarean deliveries independently increase the risk of postoperative complications. There are limited data on the influence of insulin use on the outcomes of neonates who were delivered via caesarean section. We sought to investigate the impact of insulin use in women with GDM on resuscitation rates of infants post caesarean delivery.

METHODS

A retrospective database review of women with singleton term (≥ 37 weeks) pregnancies who were on insulin for GDM delivering between January 2005 and December 2014 at a major metropolitan hospital in Sydney.

RESULTS

One thousand eight hundred and fifty-seven women with GDM were identified. The mean age was 31.01 ± 5.63 years and mean gestational period of 39.07 ± 1.00 weeks. 31.0% received insulin treatment for GDM. Women who were on insulin were older (31.9 ± 5.7 vs 30.6 ± 5.6 years, P < 0.001), had a higher body mass index (BMI) (31.2 ± 7.7 vs 29.0 ± 7.4 kg/m2, P < 0.001), higher rates of preeclampsia (7.3% vs 4.1%, P = 0.004), lower rates of alcohol consumption (0.4% vs 1.7%, P = 0.014), and had infants with lower resuscitation rates (21.2% vs 28.6%, P = 0.001). Infants who required resuscitation had a lower gestational age, lower five-minute APGAR score, and lower birth weight, length, and head circumferences. On multivariate analysis, women with GDM treated with insulin (odds ratio [OR] = 0.69, CI = 0.54-0.89, P = 0.004), higher gestational age (OR = 0.88, CI = 0.78-0.99, P = 0.032), higher maternal BMI (OR = 1.02, CI = 1.01-1.04, P = 0.005), and emergency caesarean (OR = 2.33, CI = 1.74-3.12, P < 0.001) independently predicted incidence of resuscitation.

CONCLUSIONS

The findings suggest a relationship between insulin use and reduced resuscitation rates of infants born from mothers with GDM. Further studies investigating the role, dosage, and criteria for insulin use in women with GDM are required.

Cesarean Delivery and Vaginal Birth After Cesarean Delivery Rates in a First Nations Community-Based Obstetrical Program in Northwestern Ontario

OBJECTIVE

To examine rates of cesarean delivery (CD) and vaginal birth after cesarean delivery (VBAC) and the patient profile in a community-based obstetrical practice.

METHODS

Retrospective data from 2012 to 2017 for the Sioux Lookout Meno Ya Win Health Centre (SLMHC) were compared to data from the 30 hospitals providing the same level of services (Maternity 1b: maternity care by family physicians/midwives with CD and VBAC capacity) and Ontario. SLMHC VBAC patients were then compared to the general SLMC obstetrical population. Data included maternal age, parity, comorbidities, CD, VBAC, neonatal birth weight, and Apgar scores.

RESULTS

The SLMHC obstetrical population differed from comparable obstetrical programs, with significantly higher rates of alcohol, tobacco, and opioid use and a higher prevalence of diabetes. CD rates were significantly lower (25% vs. 28%), and women delivering at SLMHC chose a trial of labour after CD almost twice as often (46% vs. 27%), resulting in a significantly higher VBAC rate (31% vs. 16%). Patients in the VBAC population differed from the general SLMHC obstetrical population, being older (7 years) and of greater parity. The neonates of VBAC patients had equivalent Apgar scores but lower rates of macrosomia and lower birth weights, although the average VBAC birth weight at 3346 g was equivalent to the provincial average.

CONCLUSION

The SLMHC obstetrical program has lower CD and higher VBAC rates than expected, despite prevalent risk factors typically associated with CD. Our study demonstrates that VBAC can be safely performed in well-screened and monitored patients in a rural setting with emergency CD capacity.

Epidemiology of mental disorders during pregnancy and link to birth outcome: a large-scale retrospective observational database study including 38,000 pregnancies

PURPOSE

To investigate the real-life epidemiology of mental disorders during pregnancy and their impact on birth outcome in an unselected low-risk population in Germany.

METHODS

Claims data of the Techniker Krankenkasse (TK) were analyzed as part of a retrospective observational study over a one-year period from 01/2008 to 12/2008 including 38,174 pregnant women. ICD-10 codes were clustered into four diagnostic groups: depression, anxiety disorders, somatoform/dissociative disorders and acute stress reactions. The relationship between mental disorders, birth mode and infant weight was tested using chi-squared tests and multivariate logistic regression. Main outcome measures included the prevalence of mental disorders during pregnancy, performed cesarean sections and infants born underweight.

RESULTS

N = 16,639 cases with at least one diagnosis from the four mental disorder diagnostic groups were identified: 9.3% cases of depression, 16.9% cases with an anxiety disorder, 24.2% cases with a somatoform/dissociative disorder, and 11.7% cases of acute stress reactions. Women diagnosed with a mental disorder were more likely to deliver their child by cesarean section ([depression: OR =1.26 (95% CI 1.14-1.39); anxiety: OR 1.11 (95% CI 1.02-1.19); somatoform disorders: OR 1.12 (95% CI 1.05-1.20); acute stress reactions: OR 1.17 (95% CI 1.07-1.28)]. Furthermore, infants of women diagnosed with an ICD-10 code for depression during pregnancy were more likely to be underweight and/or delivered preterm [OR =1.34 (95% CI 1.06-1.69)].

CONCLUSIONS

We observed substantially high prevalence rates of mental disorders during pregnancy which urgently warrant more awareness for validated screening and adequate treatment options.

Diabetes, myometrium, and mitochondria in pregnant women at term

AIMS

Poor myometrial contractility has been demonstrated in women at term with diabetes and decreased muscular mitochondrial content and/or function has been extensively implicated in the progression of type 2 diabetes. Alterations of the uterine mitochondrial phenotype in pregnant women with diabetes have yet to be investigated as a causal link to decreased myometrial contractility.

METHODS

Observational study of 18 women with diabetes (type 2 and gestational) scheduled for an elective Caesarean section at term with matching controls. A uterine biopsy and fasting blood samples were taken on the day of delivery.

RESULTS

Respiration rates in isolated mitochondria and myometrial mRNA levels of genes related to mitochondrial biogenesis were unaffected by diabetes. Mitochondrial quantity examined by quantification of the complexes of the respiratory chain and histology did not indicate alterations in mitochondrial quantity. Citrate syntase activity was higher (0.31 ± 0.02 vs. 0.24 ± 0.02 U/mg protein, P = 0.008), whereas protein content was lower in women with diabetes compared with the control group (94.6 ± 6.9 vs. 118.6 ± 7.4 mg/g wet wt, P = 0.027). Histological examinations did not support any structural alterations in the myometrium or its mitochondria.

CONCLUSION

No indication of decreased mitochondrial function, content, morphology, or localization in the myometrium at term in women with diabetes compared with controls was observed. The increase in citrate syntase activity in the myometrium could be explained by the lower protein content in the myometrium, which we suggest is due to alterations in tissue or cellular composition.

Seipin deficiency leads to defective parturition in mice

Seipin is an integral endoplasmic reticulum membrane protein encoded by Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2/Bscl2) gene. Seipin deficiency results in lipodystrophy, diabetes, muscle hypertrophy, and male infertility in both human and mouse. Seipin function in female reproduction is unknown. Bscl2-/- dams had normal embryo implantation and body weight gain during pregnancy but reduced delivery rates from 2nd to 4th pregnancies and reduced numbers of pups delivered from 1st to 4th pregnancies. Characterization of first pregnancy revealed increased gestation period and parturition problems, including uterine prolapse, difficulty in delivery, undelivered fetuses, and undelivered tissues in Bscl2-/- females. Bscl2-/- uterine weight was comparable to control at 3 weeks old but significantly increased with myometrial hypertrophy at 10 months old. In situ hybridization revealed relatively low level of Bscl2 mRNA expression in myometrium throughout pregnancy and postpartum but high level of expression in uterine luminal epithelium, suggesting that systemic effect (e.g. elevated glucose and insulin levels) rather than local seipin-deficiency in myometrium might be a main contributing factor to myometrial hypertrophy. On near-term gestation day 18.5 (D18.5), Bscl2-/- females had normal levels of serum progesterone and 17β-estradiol, indicating functional ovary and placenta. Proliferating Cell Nuclear Antigen (PCNA) staining showed minimal myometrial cell proliferation in both D18.5 Bscl2+/+ and Bscl2-/- uteri. There was strong LC3 immunostaining in Bscl2+/+ and Bscl2-/- peripartum myometrium and increased LC3 staining in Bscl2-/- peripartum uterine luminal epithelium, suggesting a potential role of seipin in regulating autophagy in uterine luminal epithelium but not myometrium. This study demonstrates an association of seipin with myometrium and parturition.

Abscisic acid: a novel uterine stimulator in normal and diabetic rats

Diabetes is usually associated with alterations in myometrial contractility with altered oxytocin responsiveness that increase the incidence of fetal and maternal morbidity and mortality. Pancreatic β-cells release abscisic acid (ABA) in response to glucose, which in turn potentiates insulin secretion. The aim of the study was to find out the effect of ABA on the uterine contractility in normal and diabetic induced rats and tried to detect its possible underlying signaling pathway. Adult non-pregnant female rats were divided into normal nondiabetic group (n = 27) and diabetic group (n = 12). The effect of ABA on the normal and diabetic isolated myometrium was determined alone or after different blockers. Spontaneous diabetic myometrial contraction showed significant decrease and less responsiveness to oxytocin, KCL, and acetylcholine than nondiabetic samples. ABA showed 60% of oxytocin stimulatory effects on myometrial contraction in a dose-response manner in both groups. Meanwhile, this effect was decreased after blocking L-type calcium channels and completely abolished after blocking prostaglandin F (FP) and inositol trisphosphate (IP₃) receptors. ABA is found to have an uterotonic effect that is mediated mainly via FP receptor through increasing the level of IP₃. So, ABA by its novel effect could be beneficial as pre-labor prescription, especially in diabetic females.

Effects of gestational diabetes mellitus on time to delivery and pregnancy outcomes in full-term pregnancies with dinoprostone labor induction

OBJECTIVE

To investigate the effects of gestational diabetes mellitus (GDM) on time to delivery and perinatal outcomes in full-term pregnancies underwent dinoprostone-induced labor.

METHODS

GDM patients that underwent labor induction with dinoprostone vaginal inserts were retrospectively recruited. Full-term pregnancies with normal glucose tolerance (NGT) that underwent labor induction at the same period were recruited as control. Time to delivery and perinatal outcomes were compared between the two groups.

RESULTS

A total of 1555 pregnancies with 226 GDM and 1329 NGT were recruited. GDM pregnancies had older ages, lower gestational age, higher body mass index (BMI) and abortion history, and more multigravida than NGT pregnancies (P< 0.05). Univariate analysis showed no significant difference in time to delivery and delivery rates between the two groups. However, after adjusted in a multivariate analysis model, the delivery rates of GDM women delivered within 12, 24, 36 or 48 h and those vaginally delivered within 12 or 36 h were significantly lower than those in the NGT group (P< 0.05). Perinatal outcomes were clinically similar between the two groups.

CONCLUSION

GDM did not affect the time to delivery, cesarean delivery and other perinatal outcomes in Chinese women underwent dinoprostone-induced labor. However, it may be associated with the lower rates of delivery within different time intervals.

Contractility Measurements of Human Uterine Smooth Muscle to Aid Drug Development

Discovery and characterization of novel pharmaceutical compounds or biochemical probes rely on robust and physiologically relevant assay systems. We describe methods to measure ex vivo myometrium contractility. This assay can be used to investigate factors and molecules involved in the modulation of myometrial contraction and to determine their excitatory or inhibitory actions, and hence their therapeutic potential in vivo. Biopsies are obtained from women undergoing cesarean section delivery with informed consent. Fine strips of myometrium are dissected, clipped and attached to a force transducer within 1 mL organ baths superfused with physiological saline solution at 37 °C. Strips develop spontaneous contractions within 2-3 h under set tension and remain stable for many hours (>6 h). Strips can also be stimulated to contract such as by the endogenous hormones, oxytocin and vasopressin, which cause concentration-dependent modulation of contraction frequency, force and duration, to more closely resemble contractions in labor. Hence, the effect of known and novel drug leads can be tested on spontaneous and agonist-induced contractions. This protocol specifically details how this assay can be used to determine the potency of known and novel agents by measuring their effects on various parameters of human myometrial contraction. We use the oxytocin- and V1a receptor antagonists, atosiban and SR49059 as examples of known compounds which inhibit oxytocin- and vasopressin-induced contractions, and demonstrate how this method can be used to complement and validate pharmacological data obtained from cell-based assays to aid drug development. The effects of novel agonists in comparison to oxytocin and vasopressin can also be characterized. Whilst we use the example of the oxytocin/ vasopressin system, this method can also be used to study other receptors and ion channels that play a role in uterine contraction and relaxation to advance the understanding of human uterine physiology and pathophysiology.

Is gestational diabetes an independent risk factor of neonatal severe respiratory distress syndrome after 34 weeks of gestation? A prospective study

PURPOSE

To evaluate if neonates delivered after 34^0/7 weeks from mothers diagnosed with gestational diabetes (GD) are exposed to an increased risk of neonatal severe respiratory distress syndrome (SRDS).

METHODS

Women with singleton pregnancy in labour after 34^0/7 weeks of gestation or admitted for planned caesarean section and who had been systematically screened for GD were eligible to participate to this prospective cohort study. Diagnosis of SRDS was defined by the association of clinical signs of early neonatal respiratory distress, with consistent radiologic features and requiring mechanical ventilation with a fraction of inspired oxygen (FiO₂) >0.25 for a minimum of 24 h and admission to neonatal intensive care unit.

RESULTS

A total of 444 women were included. GD was diagnosed in 60 patients (13.5%). A neonatal SRDS was diagnosed in 32 cases (7.2%). Compared to others, neonatal SRDS was significantly more often observed in neonates from women diagnosed with GD: 12 (20%) vs. 20 (5.2%), respectively (p < 0.001). Women whose neonates presented neonatal SRDS were significantly more likely to be obese (p = 0.002), to have undergone a caesarean section (p < 0.001) and to have received corticosteroids therapy before 34^0/7 weeks (p = 0.013). In multivariate analysis, GD was identified as an independent risk factor of neonatal SRDS (aOR 3.6; 95% CI 1.5-8.6; p = 0.005). Other risk factors were maternal obesity (aOR 2.8; 95% CI 1.1-7.1; p = 0.029) and assisted vaginal delivery (aOR 5.5; 95% CI 1.9-15.9; p = 0.002).

CONCLUSIONS

GD is an independent risk factor of neonatal SRDS after 34^0/7 weeks.

Diabetes mellitus: an independent predictor of duration of prostaglandin labor induction

OBJECTIVE

The objective of this study is to analyze the association of diabetes mellitus with progress and outcomes of prostaglandin (PG) labor induction using a retrievable vaginal insert.

STUDY DESIGN

This is a secondary analysis of data collected during the Misoprostol Vaginal Insert Trial (Miso-Obs-004), a multicenter, double-blind, randomized controlled trial of women undergoing induction of labor with PGs. The duration, characteristics and outcomes of labor were compared in women with and without diabetes. Multivariable regression analysis was performed on all outcomes of interest, adjusting for differences in baseline characteristics.

RESULTS

There were 122 women with diabetes within the sample of 1275 women who delivered during their first admission. The time to reach active labor was significantly prolonged among women with diabetes compared with those without (22.0±13.0 vs 18.5±11.1, P=0.008) as was the time to delivery (30.2±15.0 vs 26.0±12.6, P=0.004). Fewer women with diabetes delivered within 36 h (adjusted odds ratio: 0.41, 95% confidence interval: 0.26 to 0.66, P=0.0003) and 48 h (adjusted odds ratio: 0.36, 95% confidence interval: 0.19 to 0.71, P=0.004). These relationships were significant after a multivariate regression analysis of baseline characteristics that adjusted for age, race, parity, body mass index, baseline modified Bishop Score, gestational age at induction and treatment group allocation.

CONCLUSION

After PG labor induction, women with diabetes took longer to reach active labor and to deliver. We emphasize that this result comes from a secondary analysis and needs confirmation with additional studies.

Maternal body mass index and post-term birth: a systematic review and meta-analysis

Post-term birth is a preventable cause of perinatal mortality and severe morbidity. This review examined the association between maternal body mass index (BMI) and post-term birth at ≥42 and ≥41 weeks' gestation. Five databases, reference lists and citations were searched from May to November 2015. Observational studies published in English since 1990 were included. Linear and nonlinear dose-response meta-analyses were conducted by using random effects models. Sensitivity analyses assessed robustness of the results. Meta-regression and sub-group meta-analyses explored heterogeneity. Obesity classes were defined as I (30.0-34.9 kg m-2 ), II (35.0-39.9 kg m-2 ) and III (≥40 kg m-2 ; IIIa 40.0-44.9 kg m-2 , IIIb ≥ 45.0 kg m-2 ). Searches identified 16,375 results, and 39 studies met the inclusion criteria (n = 4,143,700 births). A nonlinear association between maternal BMI and births ≥42 weeks was identified; odds ratios and 95% confidence intervals for obesity classes I-IIIb were 1.42 (1.27-1.58), 1.55 (1.37-1.75), 1.65 (1.44-1.87) and 1.75 (1.50-2.04) respectively. BMI was linearly associated with births ≥41 weeks: odds ratio is 1.13 (95% confidence interval 1.05-1.21) for each 5-unit increase in BMI. The strength of the association between BMI and post-term birth increases with increasing BMI. Odds are greatest for births ≥42 weeks among class III obesity. Targeted interventions to prevent the adverse outcomes associated with post-term birth should consider the difference in risk between obesity classes.

Diabetes-induced changes in the morphology and nociceptinergic innervation of the rat uterus

The prevalence of diabetes mellitus (DM) is about 6% across the globe. This prevalence has been reported to increase in the near future. This means that the number of women with DM who would like to get pregnant and have children will also increase. The present study is aimed at investigating the morphological changes observed in the uterus after the onset of DM. The study also examined the pattern of distribution of nociceptin (NC), a neuropeptide involved in the regulation of pain, a major physiological factor during parturition. The study shows a severe atrophy of uteri as early as 15 days post DM and continued until the termination of the eight-week study. This atrophy was confirmed by light microscopy. Electron microscopy study showed atrophy of the columnar cells of the endometrium, reduced myofibril number and destruction of smooth muscle cells in the myometrium of diabetic rats compared to control. Immunofluorescence and immunoelectron microscopy studies clearly demonstrated the presence of NC in the endometrium, myometrium and on the myofibrils of the smooth muscles of both control and diabetic rat uteri. In addition, NC-positive neurons and varicose fibres were observed in the myometrium of both normal and diabetic rats. However, the expression of NC decreased after the onset of DM. Morphometric analysis showed that the number of NC-labeled cells was significantly (p < 0.05) lower in diabetic rat uteri compared to those of control. In conclusion, DM-induced uterine atrophy is associated with a decrease in the expression of NC in cells, neurons and myofibrils of the rat uterus.

Calcium plus vitamin D supplementation affects pregnancy outcomes in gestational diabetes: randomized, double-blind, placebo-controlled trial

OBJECTIVE

The present study was designed to assess the effects of Ca+vitamin D supplementation on pregnancy outcomes in women with gestational diabetes mellitus (GDM).

DESIGN

A randomized, double-blind, placebo-controlled trial was conducted among sixty women with GDM. Participants were divided into two groups to receive Ca+vitamin D supplements or placebo. Individuals in the Ca+vitamin D group (n 30) received 1000 mg Ca/d and two pearls containing 1250 µg (50 000 IU) of cholecalciferol (vitamin D(3)) during the intervention (one at study baseline and another at day 21 of the intervention); those in the placebo group (n 30) received two placebos of vitamin D at the mentioned times and placebos of Ca every day for 6 weeks. Pregnancy outcomes were determined.

SETTING

A urban community setting in Arak, Iran.

SUBJECTS

Sixty women with GDM and their newborns, living in Arak, Iran were enrolled.

RESULTS

Women treated with Ca+vitamin D had a significant decrease in caesarean section rate (23·3 % v. 63·3 %, P=0·002) and maternal hospitalization (0 v. 13·3 %, P=0·03) compared with those receiving placebo. In addition, newborns of GDM women randomized to Ca+vitamin D had no case of macrosomia, while the prevalence of macrosomia among those randomized to placebo was 13·3 % (P=0·03). Lower rates of hyperbilirubinaemia (20·0 % v. 56·7 %, P=0·03) and hospitalization (20·0 % v. 56·7 %, P=0·03) were also seen in the supplemented group of newborns than in the placebo group.

CONCLUSIONS

Ca+vitamin D supplementation for 6 weeks among pregnant women with GDM led to decreased caesarean section rate and maternal hospitalization, and decreased macrosomia, hyperbilirubinaemia and hospitalization in newborns.

Progress in understanding electro-mechanical signalling in the myometrium

In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity.

Factors associated with higher oxytocin requirements in labor

OBJECTIVE

To identify clinical characteristics associated with high maximum oxytocin doses in women who achieve complete cervical dilation.

METHODS

A retrospective nested case-control study was performed within a cohort of all term women at a single center between 2004 and 2008 who reached the second stage of labor. Cases were defined as women who had a maximum oxytocin dose during labor >20 mu/min, while women in the control group had a maximum oxytocin dose during labor of ≤20 mu/min. Exclusion criteria included no oxytocin administration during labor, multiple gestations, major fetal anomalies, nonvertex presentation, and prior cesarean delivery. Multiple maternal, fetal, and labor factors were evaluated with univariable analysis and multivariable logistic regression.

RESULTS

Maximum oxytocin doses >20 mu/min were administered to 108 women (3.6%), while 2864 women received doses ≤20 mu/min. Factors associated with higher maximum oxytocin dose after adjusting for relevant confounders included maternal diabetes, birthweight >4000 g, intrapartum fever, administration of magnesium, and induction of labor.

CONCLUSIONS

Few women who achieve complete cervical dilation require high doses of oxytocin. We identified maternal, fetal and labor factors that characterize this group of parturients.

Different patterns between mechanical and electrical activities: an approach to investigate gastric motility in a model of long-term diabetic rats

The relationship between time-courses of mechanical and electrical events in longstanding diabetes was investigated in rats. Magnetic markers and electrodes were surgically implanted in the gastric serosa of male rats. Simultaneous recordings were obtained by AC biosusceptometry, electromyography and electrogastrography one, three and six months after injections of saline (control) or alloxan (diabetic). Frequency and amplitude of contraction, abnormal rhythmic index and half-bandwidth were obtained (ANOVA P < 0.05). Antral hypomotility and gastric motility instability were observed in the signal waveform of diabetic rats at the three time points of study. The mean frequency (4.4 ± 0.4 cpm) was strictly similar, but the mechanical and electrical correlation was lowest for diabetics groups. Decreases in mechanical amplitude were observed for all diabetic groups compared with control; also the ranges of frequency were much wider in diabetes. The half-bandwidth increased since the first month in mechanical recordings and only after the third month in electrical. In diabetic animals, about 40% of gastric activity was abnormal (against 12% in control) and may reach 60% in the sixth month of mechanical recordings. The multi-instrumental approach showed a more substantial deterioration in mechanical activity and created an integrative view of gastric motility for longstanding diabetic model.

A comparison of the contractile properties of myometrium from singleton and twin pregnancies

Objective

Over half of twin pregnancies in US and UK deliver prematurely but the reasons for this are unclear. The contractility of myometrium from twin pregnancies has not been directly investigated. The objective of this research was to determine if there are differences in the contractile activity and response to oxytocin, between myometrium from singleton and twin pregnancies, across a range of gestational ages. Furthermore, we wished to determine if contractile activity correlates with increasing level of stretch, using neonatal birth weights as a marker of uterine stretch.

Methods

This was an in vitro, laboratory based study of myometrial contractility in women pregnant with one or two babies, using biopsies obtained from non-labouring women undergoing Caesarean section. Spontaneous, oxytocin-stimulated and depolarization induced contractile activity was compared.

Results

Direct measurements of myometrial contractility under controlled conditions show that the frequency of contractions and responses to oxytocin are significantly increased in twins compared to singletons. The duration of contraction however was significantly reduced. We find that contractile activity correlates with increasing levels of stretch, using neonatal birth weights as a surrogate for uterine stretch, with response to oxytocin being significantly positively correlated with birth weight.

Conclusions

We have found significant differences in contractile properties between myometrium from singleton and twin pregnancies and that increasing uterine stretch can alter the contractile properties of myometrium. We discuss the implication of these findings to preterm delivery and future studies.

What do we know about what happens to myometrial function as women age?

Much has been written about the effects of aging on reproductive function, especially female fertility. Much less is known about how aging may affect the contractility of the smooth muscle within the uterus, the myometrium. The myometrium is active through a woman’s entire life, not just during pregnancy. Here we will discuss briefly the contractile functions of the uterus and the changes it undergoes throughout the stages of a woman’s life from menstruation and the menopause, before evaluating the evidence for any changes in myometrial contractility and responses as women age, with a particular focus on women of advanced maternal age. We present original contractility analysis for the widest data set for human myometrium so far examined, and determine inherent spontaneous activity as well as responses to depolarisation and stimulation with oxytocin. Our data show that in the non-pregnant state there is a significant decrease in contractility for both spontaneous and depolarised-induced contractions, with age. We suggest that muscle atrophy and down regulation of Ca channels may account for this. Interestingly in pregnant myometrium we found a wide range of contractile ability between women and little evidence for decreased spontaneous activity between the ages of 25–40. Oxytocin responses appear to be more affected by aging, a finding that is consistent with previously reported clinical findings, and may partly be the result of membrane lipids such as cholesterol, increasing as women age. The marked differences between the age-related decline of force beyond age 30 in non-pregnant uterus, and the lack of difference in the pregnant state over this period, shows that the uterus retains its ability to respond to gestational hormones. The growth of the pregnant uterus and increase in content of myofibrillar proteins, may abolish any previous age-related force deficit. This finding is consistent with what is apparent for postmenopausal women in their 50s and 60s; that with the appropriate hormonal stimulation the uterus can allow an embryo to implant, and then without further intervention, carry the foetus to term. It is tempting therefore to speculate that unlike other well documented declines in female reproductive functions with age, the myometrium remains able to function into a woman’s 7th decade.

Poor spontaneous and oxytocin-stimulated contractility in human myometrium from postdates pregnancies

Prolongation of pregnancy i.e. going more than 10 days over the estimated due date, complicates up to 10% of all pregnancies and is associated with increased risk to both mother and fetus. Despite the obvious need for contractions of the uterus to end pregnancy, there have been no studies directly examining the role of uterine smooth muscle, myometrium, in the aetiology of prolonged pregnancy. This study tested the hypothesis that the intrinsic contractile characteristics of myometrium taken from women with prolonged pregnancy (>41 weeks and 3 days) was reduced compared to those delivering at term (39–41 weeks). We recruited women undergoing Caesarean Section (CS) delivery either pre-labour (n = 27) or in labour (n = 66) at term or postdates. The contractile ability of the postdates myometrium, whether spontaneous or elicited by oxytocin or high-K solution, was significantly reduced compared to term myometrium. These differences remained when adjusted for parity and other maternal characteristics. The findings remained significant when expressed per cross sectional area. Histological examination revealed no differences between the two groups. The contractile differences were however related to intracellular Ca transients suggesting an effect of [Ca] on reduced force production in the postdates group. In summary, myometrium from prolonged pregnancies contracts poorly in vitro even when stimulated with oxytocin and in active labour. Responses to high K⁺ and measurements of Ca suggest that alterations in excitation contraction coupling, rather than any histological changes of the myometrium, may underlie the differences between term and postdates myometrium. We show that postdates pregnancy is associated with poor myometrial activity and suggest that this may contribute to increased myometrial quiescence and hence, prolonged gestation.