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PubMed1997

The effects of parturition and peripartum complications on the peritoneal fluid composition of mares.

Abnormalities in peritoneal fluid are diagnostically useful for managing equine colic; however, their significance in post-dystocia mares is not known. This study was to determine what changes, if any, occurred following obstetrical manipulations. Peritoneal fluid samples were collected from 2 groups of foaling mares to establish control values, and from a third group that had developed clinical abnormalities (CAb,n = 14) or had made an uneventful recovery (CN,n = 36) following fetal extraction. In Group 1 mares, samples were collected before and after induced parturitions (n = 7), and although the total nucleated cell count was increased (P < 0.02) the median values for peritoneal fluid composition remained within the normal reference range. In Group 2 mares, samples were collected after unassisted foalings (n = 10) on postpartum Days 1, 3, 5 and 7, and the peritoneal fluid values remained within the normal reference range. In the Group 3 (CN) mares neither assisted vaginal delivery or fetotomy caused median peritoneal fluid values to rise above the normal reference range. Although remaining within normal limits, the total nucleated cell count was increased (P < 0.01) on Day 2. The median peritoneal fluid total protein value for Group 3 (CAb) mares was greater than the median value for Group 3 (CN) mares on Day 1 (P < 0.05) and Day 2 (P < 0.001). The peritoneal fluid total nucleated cell count in Group 3 (CAb) mares with a uterine tear, vaginal laceration involving the peritoneal cavity, or a ruptured mesocolon was greater than in Group 3 (CN) mares (P < 0.02). The median peritoneal fluid percentage of neutrophils value for Group 3 (CAb) mares was higher than for Group 3 (CN) mares on both Days 1 and 2 (P < 0.02). Elevation of a single peritoneal fluid value in the postpartum mare may be incidental; however, increases in 2 or more of these (total protein > 3.0 g/dl; total nucleated cell count > 15,000 cells/microl; percentage of neutrophils > 80%) is clinically significant.

Journal Article↗
PubMed1998

Release of proinflammatory cytokines related to luteolysis and the periparturient acute phase response in prostaglandin-induced parturition in cows.

An acute phase response was previously found in cows at parturition, which might be associated with uterine cytokine release. Five late pregnant cows were implanted with vascular catheters in both the maternal aorta and uterine vein. Blood samples were taken to study temporal relationships between changing plasma levels of proinflammatory cytokines and the periparturient acute phase response following prostaglandin (PG)-induced luteolysis at Day 275 of gestation. The plasma levels of three proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6), as well as progesterone (P4), PGFM and serum amyloid A (SAA) were measured every 4 h between PG induction and expulsion of the calf. In the arterial plasma, progesterone levels dropped to baseline levels within 10 h following PG treatment, indicative of complete luteolysis. Contrary to expectations, the uterine vein samples showed lower proinflammatory cytokine levels compared with the maternal aorta values. A classical acute phase response, as assessed by SAA, was observed during the expulsive stage, but not during luteolysis.

Animals↗
PubMed2000

Ultrasonographic study of ovarian function during early pregnancy and after parturition in the ewe.

Transrectal ultrasonography of ovaries was performed in 11 ewes from Days 10 to 26 and on Day 30 of pregnancy to record the number, size, and position of ovarian follicles > or = 3 mm in diameter and corpora lutea (CL). Transrectal and/or transabdominal ultrasonography of the uterus was performed on Days 10 to 26, 30, 35, 40, 45 and 50 of gestation to ascertain the number and position of the conceptuses. In a second experiment, ultrasonography was conducted in 15 ewes on Days 10, 25, 30, 45 and 50 of pregnancy and from Days 13 to 29 after parturition. Ovarian data were classified into ovaries without CL (Group 1), ovaries with the CL in 1 ovary (Group 2), and ovaries with the CL in both ovaries during pregnancy (Group 3). In early pregnant ewes, the total number of follicles and the diameter of all follicles > or = 3 mm were smaller (P < 0.05) in the CL-bearing ovaries (both Group 2, n = 7 and Group 3, n = 8) than in the non-CL-bearing ovaries (Group 1, n = 7), while the largest follicle diameter was significantly smaller in Group 3 than in Group 1 or 2 ovaries. The number of 3-mm follicles in Group 2 ovaries was lower (P < 0.05) than in Group 1 or 3 ovaries, but the mean number of follicles > or = 5 mm in diameter was significantly lower in Group 3 than in Group 1. The total luteal volume per ovary was higher (P < 0.001) in Group 2 than in Group 3 ovaries of early pregnant ewes. The total follicle diameter and the number of follicles growing from 3 to > or = 5 mm in diameter was lower (P < 0.05) for Group 2 ovaries of ewes that carried twins (n = 3) compared with Group 2 ovaries from ewes with singletons (n = 4). There were no differences in follicular dynamics between Group 3 ovaries and the ovaries of Group 2 in ewes that carried twins. No follicles > 3 mm were seen in the ovaries of postpartum ewes that contained CL during gestation, until Days 21 and 25 postpartum for Groups 2 (n = 10) and 3 (n = 8), respectively, and follicles reaching > or = 5 mm in diameter were detected in only 2 ovaries (Group 2), on Days 27 and 28 postpartum, respectively. We conclude that during early pregnancy in ewes there is a suppression of antral follicle growth which appears to be exerted primarily by the developing conceptus but remains confined to CL-bearing ovaries. Residual local inhibition of follicular development extends into the postpartum period.

Animals↗
PubMed1995

Control of human parturition.

Parturition is a process that is composed of five separate and distinct physiological components but which lead from one to the next and are, therefore, interdependent. As such, the regulation of myometrial contractility should not be examined in isolation but as part of this continuum. The initiation of labor begins with the biochemical events that result in the rupture of the fetal membranes, effacement of the cervix, and the switch from contractures to contractions. Because we have defined being in labor as the point at which contractions no longer revert to contractures, we suggest that labor is superimposed upon pregnancy in humans and nonhuman primates. There is no withdrawal or retreat from pregnancy, and no evidence exists that the concentrations or actions of progesterone diminish at term. Rather, the target tissues of labor are activated to perform their physiological functions, and these functions are initiated by stimulators. The best candidate for achieving activation is maternal estrogen, derived from fetal DHEAS, but major gaps in our knowledge of this process still exist. Prostaglandins are the most likely candidates as the stimulators of labor initiation, but close inspection of their precise roles also demands that clearer definition of their synthesis and actions be acquired. Coordination of and communication between the physiological events of labor motivates us to examine nontraditional mediators such as cytokines for their potential roles in the regulation of these events at normal term.

Animals↗
PubMed1998

Alterations in the hypothalamic pituitary adrenal axis during pregnancy and the placental clock that determines the length of parturition.

Although corticotrophin releasing hormone (CRH) was initially identified as a hypothalamic peptide it is also synthesised in the placenta and secreted into both the maternal and fetal circulation. The presence of large molecular weight forms in the placenta suggest that secretion may be constitutive rather that regulated. Placental CRH is bioactive but causes only modest increases in ACTH and cortisol in the pregnant woman because of agonist induced desensitisation of pituitary CRH receptors. CRH concentrations increase exponentially in maternal plasma as gestation advances. Elevated concentrations, compared with gestational age matched controls, occur in patients in preterm labour. The exponential curve describing the CRH increase is shifted to the left in women who will subsequently deliver preterm and to the right in women who will deliver post dates indicating that CRH is linked to a placental clock which determines the length of gestation. Maternal plasma CRH concentrations may be useful in identifying women at high risk of preterm delivery and CRH antagonists may prevent preterm labour. As significant CRH production by the placenta is restricted to primates future research must take into account the species specificity of the mechanisms regulating parturition.

Biological Clocks↗
PubMed1996

Calbindin-D28k mRNA expression in magnocellular hypothalamic neurons of female rats during parturition, lactation and following dehydration.

Recent studies indicate that calcium binding proteins may play a role in determining the electrical firing patterns of the hypothalamic magnocellular oxytocin (OT) and vasopressin (VP) neurons. In this study we have examined the calbindin-D28k mRNA content of magnocellular neurons in the supraoptic (SON) and paraventricular (PVN) nuclei and determined whether changes in expression correlate with the specific patterns of electrical activity displayed by these cells under different physiological circumstances. In situ hybridization with [35S]-labelled oligonucleotides revealed a heterogeneous pattern of calbindin-D28k mRNA expression in the SON and magnocellular PVN. Quantitative analysis demonstrated that the number of silver grains/cell in the dorsal half of the SON was approximately 30% higher (P < 0.05) than that of the ventral half of the nucleus. Within the PVN, calbindin-D28k mRNA-expressing neurons were detected in the medial magnocellular division of the PVN but not in magnocellular cells forming the core of the lateral magnocellular division. Dehydration for 24 h did not alter calbindin-D28k mRNA expression in the SON, PVN or cingulate cortex. In parturient and lactating rats, calbindin-D28k mRNA levels were significantly (P < 0.05) reduced in the medial magnocellular division of the PVN compared with virgin animals. No significant differences in calbindin-D28k mRNA expression were observed in either ventral or dorsal halves of the SON, or in the cingulate cortex of these animals. These results provide evidence for the differential expression of calbindin-D28k mRNA by hypothalamic magnocellular neurons and suggest that OT cells may express more calbindin-D28k mRNA than VP neurons. The reduction in calbindin-D28k mRNA expression by putative OT neurons of the PVN at the time of parturition and lactation supports the hypothesis of Li and colleagues (J. Physiol., 488 (1995) 601-608) that calbindin may play a part in determining the electrical firing patterns of magnocellular neurons. However, the absence of any similar decrease in the SON suggests that changes in calbindin-D28k mRNA expression are not essential for OT neurons to exhibit episodic bursting behavior.

Animals↗
PubMed1996

Mechanical stretching induces interleukin-8 gene expression in fetal membranes: a possible role for the initiation of human parturition.

OBJECTIVE: Interleukin-8 (IL-8) is known to play a crucial role in human parturition. We aimed to study the effect of mechanical stretching on the expression of IL-8 in fetal membranes (amniochorion) and decidua. STUDY DESIGN: We examined the expression of IL-8 and its receptor in fetal membranes (amniochorion) and decidua by immunohistochemical staining. Also, we studied the synthesis of IL-8 messenger RNA (mRNA) in the fetal membranes before and after stretching. RESULTS: We found that mechanical stretching within physiological limit increased IL-8 messenger RNA (mRNA) synthesis in fetal membranes and decidua in a time- and load-dependent manner. Application of mechanical force led to markedly increased staining of IL-8 receptor in decidual cells but not in amnion or chorion cells. CONCLUSION: These results suggested that mechanical stretching was a candidate for one of the signals important for production of IL-8 in fetal membranes and decidua and probably for initiation of a cytokine network at amniochorio-decidual interface through increased expression of IL-8 receptors.

Amnion↗
PubMed1997

A bovine oxytocin transgene in mice: expression in the female reproductive organs and regulation during pregnancy, parturition and lactation.

Transgene bovine oxytocin 3.5 (bOT3.5) consists of the bovine oxytocin structural gene flanked by 0.6 kbp of upstream and 1.9 kbp of downstream sequences. We have examined the expression of bOT3.5 in the female reproductive organs, and we show tissue-specific and physiological regulation dependent on the stage of pregnancy and lactation. In the ovary, no transgene expression could be detected during the estrus cycle, or during pregnancy. However, high levels of transgene RNA were found at day 1 of lactation. Expression dropped 10-fold by day 2 of lactation, and was undetectable thereafter. Interestingly, the expression of bOT3.5 in the mouse ovary at the beginning of lactation mimics that of the endogenous OT gene in the bovine ovary. Expression of the bOT3.5 transgene correlates with a parturition defect that results in considerable maternal mortality.

Animals↗
PubMed2000

Influence of bull biostimulation, season and parity on resumption of ovarian activity of zebu (Bos indicus) cattle following parturition.

A total of 135 postpartum suckled zebu cows were assigned randomly at calving to two treatments: cows exposed to vasectomised bulls (Mature Bull Exposure, MBE) and cows not exposed to bulls (No Bull Exposure, NBE) for a period of 150 days postpartum. This study was conducted to determine the influence of bull biostimulation, season and parity on postpartum reproductive performance of Bos indicus cattle. The trials were conducted in two seasons: cows calving in the dry season and cows calving in the rainy season. Cows with an increase in serum progesterone (P(4)) concentration of >1 ng/ml from the weekly blood samples were used to analyse the number of days from calving to the time of resumption of ovarian activity. The introduction of vasectomised bulls shortened the postpartum anoestrus in cattle following calving. Mean interval from calving to resumption of ovarian activity for the MBE cows was 71.7 days, which was significantly earlier following calving than the NBE cows with a duration of 77.8 days. By 60 to 80 days postpartum, the proportion of cows at resumption of postpartum activity for MBE cows was greater than for the NBE cows. Mean interval from calving to resumption of ovarian activity for cows that calved in the dry season was 71.3 days, which was significantly earlier than for cows that calved in the rainy season (78.6 days). At 60 days postpartum, the proportion of cows at resumption of postpartum ovarin activity for cows that calved in the dry season was greater than the cows that calved in the rainy season. Mean interval from parturition to resumption of ovarian activity for cows with three to five calvings was 65.1 days, which was significantly earlier than the value of 71. 2 days for cows with one to two calvings. By 60 to 80 days postpartum, the proportion of cows at onset of ovarian activity for cows with three to five calvings was greater than those cows with one to two calvings. Cows that calved in the dry season completed uterine involution by 24.4 days, which was significantly shorter than the duration of 26.5 days for cows that calved in the rainy season. Cows with three to five calvings completed uterine involution earlier than those with one to two calvings. It is concluded that bull-cow biostimulation influences reproductive activity in the cow possibly through olfactory cues (pheromones).

Animals↗
PubMed1990

The endocrinology of parturition in the human.

Current evidence suggests that oestrogens, progesterone, relaxin, the prostaglandins, and oxytocin are all hormones concerned to a major degree with the onset and maintenance of parturition. Oestrogens, relaxin, and the prostaglandins are particularly involved with cervical ripening, while prostaglandins, progesterone and oxytocin are more involved in regulating myometrial contractility. Catecholamines may also have some regulatory function in relation to uterine contractions. Progesterone dominance during pregnancy is associated with a firm closed cervix, few myometrial gap junctions, low calcium levels in the cells, and a quiescent myometrium. At term, a change in the oestrogen/progesterone balance favours cervical ripening and increased uterine activity. Of particular importance at the level of the muscle cell are changes in the number of oxytocin receptors; a complex interaction between cAMP and phosphoinositide metabolism governs the intracellular level of calcium, thus regulating contractile activity.

Catecholamines↗
PubMed2000

Neuroactive steroids, their precursors, and polar conjugates during parturition and postpartum in maternal and umbilical blood: 1. Identification and simultaneous determination of pregnanolone isomers.

A rapid method for the identification and measurement of four pregnanolone isomers and their polar conjugates in human plasma was developed using a simple quadrupole GC/MS system with electron impact ionization. Steroid levels were measured in the plasma of 13 and three women at delivery with subarachnoidal and epidural analgesia, respectively, and in corresponding samples of umbilical plasma. A good correlation (r=0.94, P<0.001, n=8) was found between the allopregnanolone in maternal plasma determined by GC/MS and that measured by RIA. Epipregnanolone (3beta-hydroxy-5beta-pregnan-20-one) was identified and measured for the first time in human plasma; its concentration in both maternal and umbilical plasma was much lower than that of other pregnanolone isomers. The levels of 3beta-hydroxy-pregnanolone isomers were significantly higher in the umbilical plasma than in the maternal plasma, while the differences in 3alpha-hydroxy-isomers were insignificant. The differences in conjugates were insignificant except in the case of allopregnanolone, the levels of which were lower in umbilical plasma. In all of the pregnanolone isomers, a significantly lower conjugated/unconjugated steroid ratio was found in the umbilical plasma than in the maternal plasma. The possible role of the sulfatation of pregnanolone isomers around parturition is discussed.

Adult↗
PubMedDate not supplied

Putative role of placental corticotropin-releasing factor in the mechanisms of human parturition.

Corticotropin-releasing factor is a 41-amino-acid neuropeptide synthesized in the paraventricular nucleus of the hypothalamus and released in response to stress. Its major role is the regulation of the hypothalamus-pituitary-adrenal axis by stimulation of ACTH release from the anterior pituitary gland. In addition, corticotropin-releasing factor modulates behavioral, vascular, and immune responses to stress. Corticotropin-releasing factor was first detected in the extracts of human placentas obtained at full term from spontaneous deliveries. Placental corticotropin-releasing factor content and messenger RNA expression progressively increase during normal pregnancy, and corticotropin-releasing factor levels in maternal plasma have a similar time course. The addition of corticotropin-releasing factor to primary trophoblast cell cultures stimulates ACTH secretion in a dose-dependent manner, and its action is mediated by cyclic adenosine monophosphate as second messenger. In addition, corticotropin-releasing factor is a potent local regulator of myometrial contractility and of membrane prostaglandin release. The effects of corticotropin-releasing factor in these various tissues are mediated by specific receptors. Placental corticotropin-releasing factor is also secreted into the fetal circulation and the stimulation of fetal pituitary ACTH and fetal adrenal gland dehydroepiandrosterone sulfate release in vitro has been shown. Recently, urocortin, a new peptide related to corticotropin-releasing factor, has been found in human placenta. Corticotropin-releasing factor and urocortin share some of their biologic effects, acting on the same receptors. A large-molecular-weight corticotropin-releasing factor-binding protein modulates the activity of both these peptides. Plasma corticotropin-releasing factor levels are low in nonpregnant women and become higher during the second trimester of pregnancy, rising steadily until about 35 weeks, and then increasing more rapidly until term. Vaginal delivery is a condition associated with the highest values of maternal corticotropin-releasing factor levels. Corticotropin-releasing factor is also measurable in fetal plasma (20-fold lower than in maternal circulation) and in amniotic fluid. Increased maternal plasma corticotropin-releasing factor levels characterize some gestational diseases. Women with chronic hypertension and preeclampsia have high corticotropin-releasing factor levels, and intrauterine growth retardation is associated with an activation of the hypothalamus-pituitary-adrenal axis, reflected by increased fetal plasma concentrations of ACTH, cortisol, and corticotropin-releasing factor. The role of corticotropin-releasing factor in preterm labor is uncertain, but midgestational plasma corticotropin-releasing factor levels may be higher in women delivering preterm. In these various pathologic states, maternal plasma corticotropin-releasing factor-binding protein levels undergo opposite changes, decreasing to very low levels. The endocrine-paracrine corticotropin-releasing factor/corticotropin-releasing factor-binding protein pathways may play a major role in the mechanism of human parturition.

Carrier Proteins↗
PubMed1995

Staphylococci in heifer mastitis before and after parturition.

Aseptic udder quarter secretion samples (n = 1112) from 200 mastitic and 65 non-mastitic control heifers from 160 different farms were collected for bacteriological examination and in vitro antimicrobial susceptibility testing. Coagulase-negative staphylococci (CNS) were the most frequently isolated bacteria (57.8%). The percentage of Staphylococcus aureus was 20.1, of streptococci 11.3 and of other pathogens 10.8. Staph. simulans, Staph. hyicus, Staph. xylosus and Staph. chromogenes were the most common CNS. Staph. simulans and Staph. hyicus were most frequently found in clinical samples after parturition, whereas other CNS were equally or more often found in control samples. Most CNS infections detected in the prepartum period were eliminated spontaneously or with antibiotic treatment during early lactation, but the infected quarters were more susceptible to new infection by other pathogens. Milk N-acetyl-beta-glucosaminidase activities were measured to monitor changes in inflammation. Among the CNS infections, N-acetyl-beta-glucosaminidase activities were highest for Staph. hyicus and lowest for Staph. xylosus in the lactating mammary gland of heifers. CNS were resistant to trimethoprim-sulphonamide, ampicillin and erythromycin. Staph. aureus was more resistant than CNS to beta-lactamase-sensitive penicillins.

Acetylglucosaminidase↗
PubMed2000

A mathematical model of uterine dynamics and its application to human parturition.

We have developed a simple mathematical model with three physiologically significant states to describe the changes in intrauterine pressure associated with a contraction during human parturition. The myometrium is modelled as a set of smooth muscle cells, each of which is in one of three states (quiescent, contracted, refractory) at a given time. These states are occupied according to a cycle governed by three temporal parameters. The solutions of the equations describing the model show an oscillatory behavior for particular values of these parameters, which is very similar to the time dependent development of intrauterine pressure during labor. Due to its non-linear terms, our model could lead to chaotic oscillations (in the mathematical sense), whose clinical counterpart may occur in cases of dystocia. Despite its simplicity, this model appears to be a useful guide to further investigations of the oscillatory behavior of the myometrium, or other smooth muscles, in normal and pathological situations.

Dystocia↗
PubMed2002

Cytokine concentrations in the amniotic fluid during parturition at term: correlation to lower uterine segment values and to labor.

BACKGROUND: In previous studies a significant increase in interleukin (IL)-6 and IL-8 concentrations in the lower uterine segment parallel to cervical dilatation at term could be found, however only a weak correlation to duration of labor was detected. This study compares amniotic fluid concentrations of interleukin (IL)-6 and IL-8 with those in the lower uterine segment, and the duration of labor. METHODS: Amniotic fluid and lower uterine segment specimens were obtained from 29 patients during cesarean section at term. The patients were divided into groups according to cervical dilatation (< 2 cm, 2-3.9 cm, 4-6 cm, > 6 cm) and to labor (0 h, > 0-12 h, > 12 h). Interleukin-6 and IL-8 concentrations were determined by enzyme immunoassay. RESULTS: Amniotic fluid IL-6 already increased at 2-3.9 cm (p = 0.02), while the steepest increase in IL-8 was observed at > 6 cm (p = 0.003). No correlation with lower uterine segment values was observed for either of the cytokines. However, the amniotic fluid IL-6 concentration correlated with labor (p = 0.0008). CONCLUSION: The increase in the concentration of IL-6 in the amniotic fluid earlier than its increase in the lower uterine segment supports the hypothesis that IL-6 plays a crucial role for the promotion of labor in the first place, and afterwards for the biochemical degradation processes in the lower uterine segment. The fact that the greatest increase in IL-8 concentration occurs only at > 6 cm indicates that this chemotactic cytokine has only minor significance in the initiation of parturition by its concentration in the amniotic fluid.

Amniotic Fluid↗
PubMed1980

Postpartum aggression in rats: II. Dependence on maternal sensitivity to young and effects of experience with pregnancy and parturition.

Two experiments were carried out to explore the relation between postpartum aggressive behavior in rats and other aspects of maternal behavior. In Experiment 1, nulliparous females experimentally induced to behave maternally; i.e., sensitized, failed to show elevations in aggressive responding above levels seen in untreated nulliparous controls; lactating females displayed characteristically high levels of aggression. In Experiment 2, animals in these groups were tested, along with parturient females allowed varying amounts (0 hr, 2 days, or 9 days) of postpartum exposure to young, spanning a period that is sensitive for the induction of maternal behavior. The three parturient groups responded with levels of aggression that were similar to one another and significantly higher than those seen in controls. Sensitized animals in Experiment 2 exhibited high levels of fighting; differences between these animals and those in Experiment 1 may be due to differences in both length of sensitization and ovarian cyclicity. These data indicate that the experiences of pregnancy and/or parturition prime the postparturient female to respond aggressively to an intruder later in lactation and that, unlike the initiation of pup-oriented maternal behaviors, establishment of postpartum aggression is not dependent upon pup exposure during the immediate postpartum period.

Aggression↗
PubMed1983

Studies on the role of zinc in parturition in the rat.

1. Pregnant rats were fed either low (less than 1 p.p.m.) Zn or control (40 p.p.m. Zn) diets from day 10 of gestation. They were killed at intervals during the last 96 h preceding the normal time for onset of parturition, and differences in plasma progesterone, oestradiol-17 beta and ovarian 20 alpha-hydroxysteroid dehydrogenase were assessed. 2. Gestation was prolonged in Zn-deficient rats. 3. Although the preparturient decline in plasma progesterone began at the same time in all groups, at term, plasma progesterone concentration in Zn-deficient rats remained significantly higher than in normal females. 4. Induction of ovarian 20 alpha-hydroxysteroid dehydrogenase activity was delayed by about 8 h by Zn deficiency. This delay was not observed if prostaglandin F2 alpha was injected previously. 5. The results suggest a Zn-dependent step(s) in uterine synthesis and/or release of prostanoids.

20-Hydroxysteroid Dehydrogenases↗
PubMed1999

Sudden sensorineural hearing loss with fracture of the stapes footplate following sneezing and parturition.

Three rare cases of sudden high frequency sensorineural hearing loss with longitudinal fracture of the stapes footplate are presented. In two patients it occurred after they suppressed a sneeze. In the third patient after the exertion of parturition. At exploratory tympanotomy all were found to have longitudinal fractures of the stapes footplate and two had a perilymph fistula at that site. The history and audiometric profiles in such patients should raise a high index of suspicion regarding the possibility of a stapes footplate fracture.

Adult↗