Dystocia, Uterine Healing and Uterine Innervation: An Unexplored Intersection

Advanced maternal age (AMA) and pregnancy: a feasible but problematic event

This narrative review aimed to summarize all adverse outcomes of pregnancy in advanced maternal age (AMA) to assess the age of the mother as a potentially crucial risk factor. AMA refers to women older than 35 years. While expectations and the role of women in society have undergone significant changes today, the biology of aging remains unchanged. Various pathologic changes occur in the human body with age, including chronic noncommunicable diseases, as well as notable changes in reproductive organs, that significantly affect fertility. Despite substantial advancements in technology and medicine, pregnancy in AMA remains a formidable challenge. Although there are some advantages to postponing childbirth, they primarily relate to maternal maturity and economic stability. However, regrettably, there are also many adverse aspects of pregnancy at advanced ages. These include complications affecting both the mother and the fetus. Pregnants in AMA were more prone to suffer from gestational diabetes mellitus, preeclampsia, and eclampsia during pregnancy compared to younger women. In addition, miscarriages and ectopic pregnancies were more prevalent. Delivery was more frequently completed via cesarean section, and postpartum complications and maternal mortality were also higher. Unfortunately, there were also complications concerning the fetus, such as chromosomal abnormalities, premature birth, low birth weight, admission to the neonatal intensive care unit, and stillbirth.

Uterine scars after caesarean delivery: From histology to the molecular and ultrastructural level

Uterine rupture during a trial of labor after caesarean delivery (CD) is a serious complication for mother and fetus. The lack of knowledge on histological features and molecular pathways of uterine wound healing has hindered research in this area from evolving over time. We analysed collagen content and turnover in uterine scars on a histological, molecular and ultrastructural level. Therefore, tissue samples from the lower uterine segment were obtained during CD from 16 pregnant women with at least one previous CD, from 16 pregnant women without previous CD, and from 16 non-pregnant premenopausal women after hysterectomy for a benign disease. Histomorphometrical collagen quantification showed, that the collagen content of the scar area in uterine wall specimens after previous CD was significantly higher than in the unscarred myometrium of the same women and the control groups. Quantitative real-time PCR of uterine scar tissue from FFPE samples delineated by laser microdissection yielded a significantly higher COL3A1 expression and a significantly lower COL1A2/COL3A1 ratio in scarred uteri than in samples from unscarred uteri. Histological collagen content and the expression of COL1A2 and COL3A1 were positively correlated, while COL1A2/COL3A1 ratio was negatively correlated with the histological collagen content. Transmission electron microscopy revealed a destroyed myometrial ultrastructure in uterine scars with increased collagen density. We conclude that the high collagen content in uterine scars results from an ongoing overexpression of collagen I and III. This is a proof of concept to enable further analyses of specific factors that mediate uterine wound healing.

Prolonged Dystocic Labor in Neuraxial Analgesia and the Role of Enkephalin Neurotransmitters: An Experimental Study

The investigation studied the enkephalinergic neuro fibers (En) contained in the Lower Uterine Segment (LUS) during the prolonged dystocic labor (PDL) with Labor Neuraxial Analgesia (LNA). PDL is generally caused by fetal head malpositions in the Occiput Posterior Position (OPP), Persistent Occiput Posterior Position (POPP), in a transverse position (OTP), and asynclitism (A), and it is detected by Intrapartum Ultrasonography (IU). The En were detected in the LUS samples picked up during cesarean section (CS) of 38 patients undergoing urgent CS in PDL, compared to 37 patients submitted to elective CS. Results were statistically evaluated to understand the differences in En morphological analysis by scanning electron microscopy (SEM) and by fluorescence microscopy (FM). The LUS samples analysis showed an important reduction in En in LUS of CS for the PDL group, in comparison with the elective CS group. The LUS overdistension, by fetal head malpositions (OPP, OTP, A) and malrotations, lead to dystocia, modification of vascularization, and En reduction. The En reduction in PDL suggests that drugs used during the LNA, usually local anesthetics and opioids, cannot control the "dystocic pain", that differs from normal labor pain. The IU administration in labor and the consequent diagnosis of dystocia suggest stopping the numerous and ineffective top-up drug administration during LNA, and to shift the labor to operative vaginal delivery or CS.

Dystocic Labor and Adrenergic and Noradrenergic Neurotransmitters: A Morphological Experimental Study

Authors investigated the catecholaminergic neurotransmitters (chNs) quantitative modifications in pregnant uterine Lower Uterine Segment (LUS) during prolonged labor (PL) with the fetus in an occiput-posterior position (OPP), in occiput transverse position (OTP) and in fetal head asynclitism, all diagnosed by Intrapartum Ultrasonography (IU). The chNs neurotransmitters, particularly adrenaline (or epinephrine-A) and noradrenaline (or norepinephrine-N), were evaluated in LUS fragments sampled during CS of 34 patients undergoing urgent cesarean section (CS) in PL, compared to chNs fibers in the LUS of 36 women submitted to elective CS. All results were statistically analyzed to understand the differences in neurotransmitters morphological analysis by scanning electronic microscopy examination (SEM). The LUS fragments analysis revealed a reduction of A and N fibers in LUS during PL, compared with the expression of A and N fibers in LUS during elective CS. The PL for OPP, the OTP and asynclitism, all positions causing dystocia in labor lead to a reduction in neurotransmitters in LUS, with a uterine vascularization modification and a reduction in the contractility of smooth uterine cells. The A and N neurotransmitters reduction observed in PL negatively interferes with uterine contraction during labor.