Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin

Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies. An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects. Basal levels of oxytocin increased 3-4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum. Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin. Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother's brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does

21-hydroxylase deficiency: From molecular genetics to clinical presentation

Congenital adrenal hyperplasia due to deficiency of the enzyme 21-hydroxylase (21-OH), a cytochrome P450 enzyme located in the endoplasmic reticulum and which catalyzes the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and progestene to deoxycorticosterone, is distinguished in its classical and non-classical form and is also one of the most common autosomal recessive inherited diseases in humans. The classical form appears in a rate between 1:5000 and 1:15,000 among the live neonates of North America and Europe, while the non-classical form occurs in approximately 0.2% of the general white population. This rate is especially high between the Ahskenazi Jews and a part (ie Italians, Hispanics) of the Mediterranean populations. Three alleles are associated with the 21-OH locus and can be combined in several ways in individuals who are either unaffected, heterozygote carriers, or affected with classical or non-classical disease. Variable signs and symptoms of hyperandrogenism, such as hirsutism, acne, virilization of the external genitalia and/or the body, short stature, menstrual irregularities, are common to both types of the disorder. Among the genes responsible for the synthesis of the enzyme 21-OH and the antigens of HLA system, exist both a proven genetic linkage and a proven genetic linkage disequilibrium. HLA-B-w47, HLAB(5) and HILA-B-35 are the most common haplotypes usually met in the classical form, while the haplotype HLA-B14DR1, is the most recurrent in the non-classical form of the disease. The significant advances in molecular biology and gene analysis over the past two decades have led to the development of novel sensitive methods of DNA analysis and study, such as polymerase chain reaction and southern blot analysis. Thus, it has been revealed that the synthesis of enzyme 21-OH is controlled by two genes, the active CYP21B gene and the CYP21A pseudogene. All three forms of the disease have a known sequence of gene changes owing to mutations in isolated proteins or whole series of genes due to translocations or deletions of genetic material

Sigmoid colon cancer during pregnancy

Colorectal carcinoma during pregnancy is a rare event. We report a 23-year-old primigravida with advanced stage adenocarcinoma of the sigmoid colon diagnosed at 34 weeks of gestation. A healthy female infant was delivered by cesarean section. The treatment of choice was chemotherapy. The patient died 3 months after delivery. (C) 2002 Published by Elsevier Science Ireland Ltd

The prevalence of non-classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency in greek women with hirsutism and polycystic ovary syndrome

The study was aimed to find out the prevalence of non-classical congenital adrenal hyperplasia (NC-CAH) due to 21-hydroxylase deficiency (21-OHdef) among Greek women with hirsutism and polycystic ovary syndrome (PCOS) and to compare the results of ACTH stimulated 17-hydroxyprogesterone 60 min (17-OHP60) values, with human leukocyte antigens (HLA) phenotypes, in any patient diagnosed as having NC-CAH. One hundred and seven women with hirsutism and PCOS were included in the study. All were presented at the Reproductive Endocrinology Outpatient Clinic with hirsutism and PCOS. After ACTH stimulation test, 10 women were diagnosed as having NC-CAH because of high 17-OHP60 values ≥36 nmol/l, and 97 as having PCOS. Ten (10.3%) of the 97 women presented hormonal findings compatible with adrenal hyper-response due to ACTH testing, because of hyperstimulated 17-OHP60 values ≥21 nmol/l and <32 nmol/l. The HLA typing of 10 patients with NC-CAH revealed the phenotypes B14, DR1, B35, B7 and B44 which present positively genetic linkage disequilibrium with 21-OHdef, as reported in the literature. In conclusion: In Greek women with hirsutism and PCOS we have found that: a. The prevalence of NC-CAH among these women is relatively high and reaches at 10%. b. The HLA phenotypes B14, DR1, B35, B7 and B44 were found in high frequency in these NC-CAH patients. c. Adrenal NC-CAH due to 21-OHdef as well as adrenal hyperactivity, revealed after ACTH testing, constitutes an important reason of hirsutism and PCOS in these Greek women and both reach a rate of 20%

Abnormal fetal heart rate patterns during the active phase of labor: The value of fetal oxygen saturation

Objective: To determine the predictive value of intrapartum fetal oxygen saturation (SO2) for prediction of an umbilical artery pH less than 7.15 at birth in labors complicated by abnormal fetal heart rate traces. Study design: Eighty-five primigravidas in spontaneous labor complicated by abnormal fetal heart rate traces underwent fetal SO2 monitoring using the fetal pulse oximetry technique. Cases with an SO2 of < 30% were delivered by Cesarean section. Umbilical artery pH was measured at birth in all women. Results: With the value set of 30% as the cut-off point of fetal oxygen saturation, the positive predictive value for umbilical artery pH of < 7.15 was 61.5% and the negative predictive value was 95.8%, with a sensitivity of 72% and a specificity of 93%. Conclusions: Fetal pulse oximetry is a promising technique for assessment of fetal well-being during labor and may decrease the number of unnecessary Cesarean sections