Perineal Injury in Nulliparous Women Giving Birth at a Community Hospital: Reduced Risk in Births Attended by Certified Nurse‐Midwives

Introduction : Our objective was to determine if there is a difference in rates of perineal injury sustained by nulliparous women attended by obstetricians compared with certified nurse‐midwives (CNMs) at a US community hospital. Methods : We analyzed retrospective data for 2819 women who spontaneously gave birth to singleton, vertex, term, live infants between 2000 and 2005. The independent variable was attendant type (obstetrician or CNM). The main outcome variables were intact perineum, episiotomy, and spontaneous perineal lacerations. Multivariate logistic regression was used to adjust for six potential confounders: macrosomia, maternal age, epidural anesthesia, oxytocin administration, medical insurance status, and ethnicity. Results : The odds ratios (ORs) for obstetrician‐attended births versus CNM‐attended births were significant for a spontaneous minor perineal laceration versus intact perineum (OR = 1.82; 95% confidence interval [CI], 1.33–2.48), spontaneous major laceration versus intact perineum (OR = 2.29; 95% CI, 1.13–4.66), and episiotomy use versus no perineal injury, with or without extension (OR = 2.94; 95% CI, 2.01–4.29). Discussion : We found that the prevalence and severity of perineal injury, both spontaneous and from episiotomy use, were significantly lower in CNM‐attended births. J Midwifery Womens Health 2010;55:243–249 c̊ 2010 by the American College of Nurse‐Midwives.     

Perinatal Outcomes of Women Intending to Give Birth in Birth Centers in Australia

Abstract: Background: A recent Australian study showed perinatal mortality was lower among women who gave birth in a birth center than in a comparable low‐risk group of women who gave birth in a hospital. The current study used the same large population database to investigate whether perinatal outcomes were improved for women intending to give birth in a birth center at the onset of labor, regardless of the actual place of birth. Methods: Data were obtained from the National Perinatal Data Collection (NPDC) in Australia. The study included 822,955 mothers who gave birth during the 5‐year period, 2001 to 2005, and their 836,919 babies. Of these, 22,222 women (2.7%) intended to give birth in a birth center at the onset of labor. Maternal and perinatal factors and outcomes were compared according to the intended place of birth. Data were not available on congenital anomalies, or cause, or timing of death. Results: Women intending to give birth in a birth center at the onset of labor had lower rates of intervention and of adverse perinatal outcomes compared with women intending to give birth in a hospital, including less preterm birth and low birthweight. No statistically significant difference was found in perinatal mortality for term babies of mothers intending to give birth in a birth center compared with term babies of low‐risk women intending to give birth in a hospital (1.3 per 1,000 births [99% CI = 0.66, 1.95] vs 1.7 per 1,000 births [99% CI = 1.50, 1.80], respectively). Conclusions: Term babies of women who intended to give birth in a birth center were less likely to be admitted to a neonatal intensive care unit or special care nursery, and no significant difference was found in other perinatal outcomes compared with term babies of low‐risk women who intended to give birth in a hospital labor ward. Birth center care remains a viable option for eligible women giving birth at term. (BIRTH 37:1 March 2010)     

Cesarean and Vaginal Birth in Canadian Women: A Comparison of Experiences

Abstract: Background: Many publications have examined the reasons behind the rising cesarean delivery rate around the world. Women’s responses to the Maternity Experiences Survey of the Canadian Perinatal Surveillance System were examined to explore correlates of having a cesarean section on other experiences surrounding labor, birth, mother‐infant contact, and breastfeeding. Methods: A randomly selected sample of 8,244 estimated eligible women stratified primarily by province and territory was drawn from the May 2006 Canadian Census. Completed responses were obtained from 6,421 women (78%). Results: Three‐quarters of the women (73.7%) gave birth vaginally and 26.3 percent by cesarean section, including 13.5 percent with a planned cesarean and 12.8 percent with an unplanned cesarean. In addition to more interventions in labor, women who had a cesarean birth after attempting a vaginal birth had less mother‐infant contact after birth and less optimal breastfeeding practices. Conclusion: Findings from the Maternity Experiences Survey indicated that women who have cesarean births experience more interventions during labor and birth and have less optimal birthing and early parenting outcomes. (BIRTH 37:1 March 2010)     

Chronic treatment of cycling rhesus monkeys with low doses of the antiprogestin ZK 137 316: morphometric assessment of the uterus and oviduct

The long-term effects of the antiprogestin ZK 137 316 on reproductive tract morphology in rhesus macaques were investigated. The monkeys were injected daily (i.m.) for five menstrual cycles with vehicle or 0.01, 0.03 or 0.1 mg ZK 137 316/kg body weight. Reproductive tracts (n = 3/ group) were collected during the mid-luteal phase (day 8) of the fifth cycle in the control, 0.01 and 0.03 mg/kg groups, or 6-7 days after the oestradiol peak in the 0.1 mg/kg group. ZK 137 316 treatment resulted in a dose-dependent atrophy of the endometrium, marked by reduced mitotic activity in the glands, compaction of the stroma, degradation of spiral arteries and dilation of veins. There was no effect of ZK 137 316 on myometrial or oviductal weight. Treatment with 0.1 and 0.03 mg/kg, but not 0.01 mg/kg resulted in fully ciliated and secretory oviducts, indicating a dose-dependent blockade of progesterone antagonism of oestrogen-dependent oviductal differentiation. In the endometrium, the suppressive action of progesterone on oestrogen and progestin receptors was also blocked by ZK 137 316 in a dose-dependent manner. However, endometrial atrophy appeared due to inhibition of progesterone action together with a blockade of oestrogen-dependent proliferation. The profoundly suppressed endometrium produced by chronic low-dose ZK 137 316 treatment is unlikely to support implantation. Such treatment may therefore provide a novel contraceptive modality.      

Oocyte maturation and embryonic failure

Embryonic development is readily compromised by imperfectionsintroduced during the process of oocyte maturation. We discussthe nature and causes of these imperfections, particularly inoocytes exposed to inappropriate hormonal regimes in vivo orto culture systems designed to induce the maturation of oocytesin vitro. The acquisition of developmental competence involvesthe synthesis and storage of a wide range of molecules duringoocyte growth followed by the reprogramming and ordered utilizationof these stored products during maturation, fertilization andearly embryogenesis. The regulatory signals for these molecularchanges are produced by the follicle cells in response to circulatinglevels of gonadotrophins; we report that some ovarian stimulationprotocols distort these signals thereby disrupting molecularreprogramming of the oocyte and reducing subsequent developmentalcompetence. The aspiration of immature oocytes from antral folliclesfollowed by their maturation in vitro is a potential alternativeto hormonal stimulation of patients in IVF treatment. Althoughrelatively successful in a variety of animals, the productionof fully viable human embryos by in-vitro maturation is stillunsatisfactory despite the use of a wide variety of cultureprotocols. Our data suggests that the key to maturation andembryo viability in vitro resides in the follicle cell compartmentrather than the oocyte. Because of rapid luteinization changes,follicle cells in culture probably fail to provide the maturingoocyte with the necessary ordered set of instructive signalsand nutrients needed for the acquisition of developmental competence.Although much remains to be discovered about the nature, concentrationand transmission of signals, nevertheless it is already clearthat different steroids, matrix metalloproteinases and growthfactors are involved in conferring viability on the maturingoocyte. Major improvements in the yield of viable embryos fromin-vitro matured oocytes can be anticipated from a systematicanalysis of somatic signals from the pre-ovulatory follicle.     

The effect of bloodletting on exercise performance in a subject with a high-affinity hemoglobin variant

We studied two young army recruits with erythrocytosis. One had a variant hemoglobin with high affinity for oxygen (hemoglobin Osler, also known as Fort Gordon and Nancy, beta 145 Tyr leads to Asp). The other had normal oxygen affinity and erythrocytosis of undetermined etiology. Both were asymptomatic. We studied exercise capacity on a cycle ergometer before and after hemodilution. In the subject with high oxygen affinity, hemodilution resulted in reduced maximal work and increased heart rate at every work level. In addition, minute ventilation and arterial lactic acid increased, while anaerobic threshold decreased, indicating diminished oxygen supply to tissues. In contrast, the subject with normal oxygen affinity had no significant changes in exercise performance after hemodilution. These results suggest that when blood oxygen affinity is high, loss of efficiency in tissue oxygenation can be expected after phlebotomy or hemodilution. Therefore, it may be useful to measure blood oxygen affinity and exercise performance in polycythemic subjects in whom such procedures are intended to ameliorate symptoms of hyperviscosity.     

补骨脂总香豆素的平喘作用

目的：研究补骨脂总香豆素的止喘作用。方法：豚鼠ip12．5mg/kg的补骨脂总香豆素,同时设立氨茶碱和生理盐水作对照,观察其豚鼠过敏性哮喘和组胺性哮喘潜伏期及死亡率的影响。结果：补骨脂总香豆素对过敏性哮喘和组胺性哮喘的潜伏期均有显著的延长作用（P＜0．01和P＜0．05）;显著降低动物死亡率（P＜0．05）。结论：补骨脂总香豆素对哮喘有明显的拮抗作用。     

Liposarcoma of the hypopharynx

A case of the unusual condition of liposarcoma of the hypopharynx extending submucosally down the oesophagus in a 64 year old male is reviewed. The clinical, radiological and pathological features are presented and the role of various radiological modalities is discussed.