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PubMed1993

Effects of parturition, suckling and pseudopregnancy on variables of disease activity in the B/W mouse model of systemic lupus erythematosus.

OBJECTIVE: The pituitary hormone, prolactin, accelerates systemic lupus erythematosus in NZB/NZW F1 (B/W) mice. Our study evaluated disease activity in B/W females experiencing the physiologic hyperprolactinemia of mating, pregnancy, suckling, and pseudopregnancy. METHODS: Nonsuckling postpartum, suckling and pseudopregnant mice were compared to virgin females. Serum prolactin, anti-DNA antibodies (anti-DNA), gp70-anti-gp70 immune complexes, IgM, IgG, albuminuria, and renal function were monitored serially. RESULTS: Females that whelped 2 litters had apparent stimulation of anti-DNA; those that suckled their young had similar premature appearance of anti-DNA as well as delayed, but marked, hypergammaglobulinemia. Pseudopregnant mice, which characteristically secrete repeated surges of prolactin, had significant acceleration of multiple variables of disease activity. CONCLUSIONS: Pregnancy, parturition and suckling did not immediately accelerate lupus in B/W dams, and longevity was not affected in females that had borne litters. Pseudopregnancy was the most effective stimulator of variables of autoimmunity.

Albuminuria↗
PubMed1993

Comparison of maternal serum lipids before and during parturition.

OBJECTIVE: To investigate peripartum progesterone metabolism by measuring its lipid precursors. METHODS: Serum was collected from eight pregnant women not in labor during the third trimester and again during active labor. Samples were analyzed using quantitative spectrophotometric absorbance techniques for apolipoprotein A-1, high-density lipoprotein cholesterol (HDL), and total cholesterol. RESULTS: Remote from labor, the mean gestational age antepartum was 35.6 weeks; during active labor it was 39.2 weeks. The amount of apolipoprotein A-1 present was 182.0 mg/dL before labor and 156.8 mg/dL during active labor; HDL cholesterol was 59.3 mg/dL before labor and 37.5 mg/dL during active labor, and total cholesterol was 226.6 mg/dL before labor and 144.1 mg/dL during active labor. All differences were significant at P < .05. CONCLUSION: Maternal serum lipids associated with progesterone metabolism appear to decrease in the peripartum period. Progesterone metabolism and parturition may be correlated with these lipid changes, thus identifying patients about to enter labor.

Apolipoprotein A-I↗
PubMed1995

[Effect of housing of sows during parturition and the vitality of the piglets].

Group housing of sows had a positive effect on parturition, but led to a decrease in litter size by 1.2 alive born piglets per litter and a reduce in mean birth weight of piglets by 70 g; it had no effect on the vitality of piglets. A high birth weight, a long lasting placento-fetal blood transfer and an air temperature of more than 20 degrees C are factors with significant influence on vitality of neonates.

Animals↗
PubMed1995

Pathways to parturition.

Oxytocin is secreted during parturition to stimulate myometrial contractions and birth. Prior to the start of labour, oxytocin neurones undergo changes to prepare for optimal secretion during labour. Thus, during late pregnancy oxytocin secretion is limited by endogenous opioid inhibition. This does not appear to act at the oxytocin nerve terminals in the neural lobe since they in fact become desensitised to opioid inhibition, responding less to either the general opioid antagonist, naloxone, or to the specific kappa-opioid agonist U50,488, and kappa-receptor binding decreases. However, removal of opioid inhibition on oxytocin neurones by naloxone activates oxytocin cell bodies and there is an increase in the number of cells expressing Fos protein in the supraoptic nucleus. This action is mediated via mu- and not kappa-opioid receptors since norBinaltorphimine (kappa-antagonist) is ineffective. Endogenous opioids are likely to act pre-synaptically on inputs to oxytocin neurones, especially those from the brainstem since naloxone potentiates the firing rate response of oxytocin neurones to intravenous cholecystokinin administration which acts via noradrenergic neurones. The endogenous opioid, beta-endorphin may be responsible for inhibition of oxytocin neurones as both the peptide content and its precursor proopiomelanocortin mRNA content increase in the arcuate nucleus during pregnancy, whereas expression of the co-localized opioids, prodynorphin or proenkephalin A, in magnocellular neurones does not alter.

Animals↗
PubMed1997

Milk production and reproductive performance in dairy cows given bovine respiratory syncytial virus vaccine prior to parturition.

OBJECTIVE: To assess the effect of vaccination against bovine respiratory syncytial virus on milk production, reproductive performance, and health in lactating dairy cows. DESIGN: Prospective randomized block design. ANIMALS: 385 Holstein dairy cows and heifers. PROCEDURE: Cows were grouped by lactation number, season of calving, and previous mature equivalent 305-day milk production (where appropriate). Prior to parturition, cows and heifers were randomly assigned to be vaccinated i.m. against infectious bovine rhinotracheitis, bovine viral diarrhea, and parainfluenza 3 viruses by use of a three-way vaccine, or to be vaccinated against those viruses as well as bovine respiratory syncytial virus, using a four-way vaccine. Milk production was measured daily through 305 days of lactation. Reproductive and medical records were reviewed to obtain insemination dates and record medical problems of cows in each vaccine treatment group. RESULTS: Compared with the three-way vaccine, administration of the four-way vaccine was associated with higher milk production (1.39 kg [3.06 lb] more milk/d) in first-parity cows during the first 21 weeks of lactation. Vaccination did not have any effect on milk production after the first 21 weeks of lactation in cows of any parity. Conception rates at first insemination were higher for four-way vaccinated first-parity cows than for three-way vaccinated first-parity cows (54.6 vs 32.7%). Compared with second-parity cows that received the three-way vaccine, first insemination conception rate was improved for second-parity cows vaccinated with the four-way vaccine (28.9 vs 47.8%, respectively). In cows of third or greater parity, first insemination conception rate was not different between the 2 vaccine treatment groups. CLINICAL IMPLICATIONS: Vaccination of heifers against bovine respiratory syncytial virus prior to partrition may increase milk production and first insemination conception rates.

Animals↗
PubMed1976

Changes in the concentrations of urea, glucose and some mineral elements in the plasma of the ewe during induced parturition.

Four Finnish Landrace X Dorset Horn ewes were each given an intramuscular injection of 15 mg of dexamethazone on day 142 of gestation. Four ewes with the same fetal numbers were used as controls. Administration of the corticosteroid reduced the mean gestation length from 146-5 to 143-3 days and had no effect on the pre-lambing concentrations of Na, Cl, Ca P and Mg in the maternal plasma or on blood pH. There was a slight but significant (P less than 0-05) decrease in plasma K before lambing in the treated ewes. Plasma urea and glucose concentrations were not affected by treatment. There was a significant increase in the plasma concentration of glucose in both groups of ewes immediately after parturition.

Animals↗
PubMed1997

[Effect of normal parturition on activity of clinically relevant enzymes in blood plasma of goats and kids].

Blood of 24 healthy goats of different breeds in the age between two and six years as well as their 36 lambs in the peripartal period was taken at regular intervals from the day 10 ante partum up to the day 30 post partum. The content of plasma--nonspecific, clinical essential enzymes as well as the selenium content--has been examined. 1. Normal parturition shows an influence on the enzyme activity in plasma. Abundant alterations in concentration (p < or = 0.05-0.001) are detectable in AST, LDH, alpha-HBDH, GGT, GLDH and CK. GGT responds indistinctly to birth. GLDH-concentration is significant higher in the lactation period (p < or = 0.01). 2. The registration of OCT in blood plasma and serum of goats is possible but the activity of the enzyme in plasma and serum is slight. 3. In the blood of new born lambs a high plasma activity of CK and GGT can be found. Up to day 5 post natum the activity of CK descends to post partum adult level and up to day 30 post natum lower enzyme values than those of adult goats are found. GGT activity at day of birth after colostrum uptake is more than 5 times higher than at day 5 post natum. Up to day 30 post natum the activity remains above the mean of adult goats.

Animals↗
PubMed1976

Changes in the renin-angiotensin system in normotensive and hypertensive women during pregnancy and parturition.

Plasma renin activity, plasma renin concentration and plasma angiotensin II were measured in 18 primigravid women and 17 multiparous women between 37 and 42 weeks of gestation. Seven of the primigravid and seven of the multiparous women were admitted to hospital because they developed hypertension during pregnancy. In the primigravid group, the mean angiotensin II level was significantly higher in the hypertensive than in the normotensive women. A highly significant correlation was found between diastolic blood pressure and plasma angiotensin II levels. Although a similar trend was seen in the multiparous women, there was a wide scatter of values and the relationship between diastolic blood pressure and plasma angiotensin II was not significant. No correlation could be established between plasma renin concentration and angiotensin II levels. However, there was a trend towards a negative correlation between plasma renin activity and plasma angiotensin II, suggesting that high angiotensin levels may suppress renal renin release. The influence of parturition on plasma angiotensin II levels was investigated in 12 women. Maternal plasma angiotensin II levels were significantly higher in the second stage of labor than in women delivered by elective cesarean section.

Angiotensin II↗
PubMed1997

C-reactive protein concentration in the sera of pregnant women with imminent premature parturition and preterm amniorrhea.

C-reactive protein (CRP) levels were evaluated during spontaneous labour, in imminent premature parturition (IPP) and after preterm rupture of oocyst membranes (PROM). Increasing CRP level during spontaneous labour was found in 16.6% parturients. Elevated CRP level in patients with IPP makes it impossible to predict premature labour. In parturients with PROM, increase in CRP level makes further infection predictable only in a few cases.

C-Reactive Protein↗
PubMed1976

Plasma cortisol levels in human fetus during parturition.

In several mammalian species, the fetal adrenal cortex plays an important role in the spontaneous onset of labor. No conclusive evidence has yet been presented that a similar mechanism is active in humans. Although in some previous studies the cortisol concentration in human cord blood has been found higher after spontaneous labor than after induced labor, it has not been possible to determine whether this rise in the fetal cortisol level precedes the onset of parturition or is a consequence of labor. In the present study, starting at the earliest possible stage of labor, fetal scalp blood samples were taken sequentially during 16 spontaneous and 13 induced vaginal deliveries. Cortisol levels in these 2 goups of samples were compared with each other and also with cord blood cortisol levels in 11 patients undergoing elective cesarean section. The initial fetal cortisol levels did not differ between groups with different modes of labor onset. A pronounced rise of plasma cortisol levels occurred during labor in simultaneously sampled maternal and fetal blood. These results do not support the concept of a role for the fetal adrenal cortex in the initiation of labor in humans; they invalidate the use of cortisol concentration in cord blood for the estimation of prelabor fetal cortisol level. The origin of the cortisol surge in fetal plasma during labor and also whether the fetal adrenocortical function responds to the stress of labor are discussed. It is concluded that the rise of fetal cortisol levels during labor might mainly be a reflection of the maternal response to stress.

Amniotic Fluid↗
PubMedDate not supplied

[Cytokine concentrations and expression of adhesion molecules in the lower uterine segment during parturition at term: relation to cervical dilatation and duration of labor].

OBJECTIVE: To determine the concentrations of tumor necrosis factor (TNF)alpha, interleukin (IL)beta, IL-6 and IL-8 and the expression of endothelial leukocyte adhesion molecule-1 (ELAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the lower uterine segment during parturition at term and to investigate correlations with the stage of cervical dilatation and with the duration of labor. PATIENTS AND METHODS: Biopsy specimens were taken from the lower uterine segment of 59 women undergoing non-elective cesarean sectin at term at different stages of cervical dilatation (< 2 cm, n = 17; 2-3 cm, n = 12; 4-6 cm, n = 13; > 6 cm, n = 17) after varying length of the time in labor (1-6 h, n = 18; > 6-12 h, n = 16; > 12-24 h, n = 15; > 24 h, n = 10). The concentrations of TNF alpha, IL-1 beta, IL-6 and IL-8 in protein extracts of these specimens were determined by enzyme linked immunosorbent assays and the expression of ELAM-1 and VCAM-1 was studied by immunohistochemistry. Staining was considered negative if < 5% of the endothelial cells were stained and positive if > or = 5% were stained. RESULTS: At < 2 cm dilated cervix the median concentrations of TNF alpha, IL-1 beta, IL-6 and IL-8 were 8.0 pg/mg total protein (TP), 1.3 pg/mg TP, 12.6 pg/mg TP and 17.2 pg/mg TP, respectively. At 4-6 cm dilatation the median concentrations were increased (TNF alpha: 22.2 pg/mg TP [P = 0.05], IL-1 beta: 22.2 pg/mg TP [P < 0.05], IL-6: 1226 pg/mg TP [P < 0.05], IL-8: 2081 mg/mg TP [P < 0.05]). At > 6 cm dilatation no further increase was observed. The expression of ELAM-1 and VCAM-1 was significantly greater at > 6 cm dilatation than < 2 cm dilatation (P < 0.001 and 0.05, respectively). With increasing duration of labor, the concentrations of IL-1 beta, IL-6 and IL-8 (but not of TNF alpha) increased and were significantly higher at > 6 cm dilatation than at < 2 cm (P < 0.05). Expression of ELAM-1 and VCAM-1 did not vary with duration of labor. CONCLUSIONS: These first investigations of cytokines and cell adhesion molecules in the lower uterine segment at both different stages of cervical dilatation and different duration of labor support the decisive role of cytokines for normal cervical dilatation. Local changes in the lower uterine segment independent from the effects of labor (e.g. increase of endothelial adhesivity) seem to be of special importance in this process.

Cell Adhesion Molecules↗
PubMed1998

[Thyroid hormones in Old German Black Pied- and Holstein-Friesian suckling calves. Effects of parturition and postpartum adaptation].

The present trial deals with the effects of birth stress on the thyreoidea respectively on the thyroxine- and triiodthyronine-concentration as well as on their unbound fraction (FT4 and FT3) of suckler calves and the evolution of those parameters in the first three months of life. T4- and T3 concentrations in blood serum of calves were beyond maternal levels increasing significantly in the first 24 hours with strong individual specificity and reaching levels of adult animals at the end of the three-month-period. The different increasing rates of the four parameters show a stimulation of the thyreoideal activity and of the monodejodinase-system as well and they show also a greater decomposition rate of the binding proteins. An influence of the course of parturition on the T3 level p.n. and the T4/T3 ratio in the first 24 hours could be disclosed. The hormone concentrations p.n. showed correlations to the pH and pCO2 of the neonatal calves. For T4 and T3 a strong influence of maternal levels on the hormone levels of the calves p.n. could be ascertained. Effects of breed, surrounding temperatures and type of husbandry on the investigated parameters could be established.

Acclimatization↗
PubMed1976

Initiation of human parturition. V. Progesterone binding substance in fetal membranes.

This study was undertaken as part of an investigation of the potential role of progesterone metabolism within fetal membranes in the initiation of human labor. The results of this study provide evidence that a progesterone binding substance is present in amnion and chorion laeve during the last few days of pregnancy. This substance binds progesterone, cortisol, and 5alpha-dihydroprogesterone but does not bind 20alpha-hydroxy-4-pregnen-3-one, R 5020, or dexamethasone. We conclude that this is a previously undescribed progesterone binding substance and propose a possible mechanism by which this substance may be involved in the initiation of human parturition.

17-alpha-Hydroxypregnenolone↗
PubMed1976

[Experimental hypocalcemia as a model for the study of etiopathogenetic factors of hypocalcemic hysteroparesis due to parturition in dairy cows].

Hypocalcaemia was experimentally induced to cattle of different age groups, and the resulting model showed that intraplasmic parathormone-induced calcium rise due to activation of calcium from the apatite crystals of the skeletal depot was a function of age and a sufficiently plausible explanation for age-dependent growing morbidity rates in the context of hypocalcaemic hysteroparalysis in concomitance with parturition. High vitamine D3 doses are recommended for systematic prophylaxis.

Animals↗
PubMed2005

Observation of parturition in the Mexican mantled howler monkeys (Alouatta palliata) on the Island of Agaltepec, Veracruz State, Mexico.

We observed a birth in a group of Mexican mantled howler monkeys (Alouatta palliata) living under semi-free-ranging conditions on Agaltepec Island, Catemaco, Veracruz, Mexico. Although we could not quantify contractions, we were able to record a complete description of the sequence of events that resulted in a successful birth. Nine minutes passed from the release of the amniotic fluid to the total emergence of the infant. Although all group members were resting relatively close to the female when the birth occurred, none approached her until the postpartum period. Only then did several individuals briefly inspect the newborn and then resume their foraging activities.

Alouatta↗
PubMed2003

Three-dimensional ultrasound imaging of the pelvic floor: the effect of parturition on paravaginal support structures.

OBJECTIVE: It is assumed that support of the female urethra and bladder is maintained by paraurethral and paravaginal fascial structures, with hypermobility resulting from delivery-related trauma. This study used three-dimensional translabial ultrasound to assess these structures and document peripartal changes. DESIGN: A clinical observational pilot study was performed on 26 nulliparous women recruited in the third trimester of pregnancy. They underwent translabial two- and three-dimensional ultrasound. Twenty-three women were again seen 2-5 months postpartum. The assessor was blinded against two-dimensional ultrasound and delivery data. Vaginal tenting was rated as being present, indeterminate or absent at each of three levels, and was correlated with bladder neck descent (BND) and urethral rotation on Valsalva maneuver. RESULTS: Tenting was visible at all levels in 21 of 26 women antepartally. In three women tenting was absent on one level; in two cases tenting was rated indeterminate. There was no significant difference in BND between women with visible tenting and those without. The BND range for women with intact tenting was 5.4-41.6 mm. Twenty-one of the 26 women were included in the postpartum analysis. Of these, obvious peripartal changes were documented in five. Loss of tenting did not correlate significantly with changes in BND. CONCLUSIONS: Most nulliparous women showed evidence of intact paravaginal support structures. Tenting occurred in women with widely varying BND, implying that excess bladder neck mobility may be due to increased fascial compliance. Postnatally, fascial disruption was suspected in a minority of patients only. In some women delivery-related changes may be due to attenuation rather than disruption of structures.

Adult↗