Spinal anesthesia-induced hypotension: a risk comparison between patients with severe preeclampsia and healthy women undergoing preterm cesarean delivery.

We previously showed that, in comparison with term healthy parturients, patients with severe preeclampsia had a less frequent incidence of spinal hypotension, which was less severe and required less ephedrine. In the present study, we hypothesized that these findings were attributable to preeclampsia-associated factors rather than to a smaller uterine mass. The incidence and severity of hypotension were compared between severe preeclamptics (n = 65) and parturients with preterm pregnancies (n = 71), undergoing spinal anesthesia for cesarean delivery (0.5% bupivacaine, sufentanil, morphine). Hypotension was defined as the need for ephedrine (systolic blood pressure <100 mm Hg in parturients with preterm fetuses or 30% decrease in mean blood pressure in both groups). Apgar scores and umbilical arterial blood pH were also studied. Neonatal and placental weights were similar between the groups. Hypotension was less frequent in preeclamptic patients than in women with preterm pregnancies (24.6% versus 40.8%, respectively, P = 0.044). Although the magnitude of the decrease in systolic, diastolic, and mean arterial blood pressure was similar between groups, preeclamptic patients required less ephedrine than women in the preterm group to restore blood pressure to baseline levels (9.8 +/- 4.6 mg versus 15.8 +/- 6.2 mg, respectively, P = 0.031). The risk of hypotension in the preeclamptic group was almost 2 times less than that in the preterm group (relative risk = 0.603; 95% confidence interval, 0.362-1.003; P = 0.044). The impact of Apgar scores was minor, and umbilical arterial blood pH was not affected. We conclude that preeclampsia-associated factors, rather than a smaller uterine mass, account for the infrequent incidence of spinal hypotension in preeclamptic patients.

Severe hyperinsulinaemic hypoglycaemia in a baby born to a mother taking oral ritodrine therapy for preterm labour.

Hyperinsulinism of infancy is a major cause of persistent hypoglycaemia in the newborn period. Transient mild self-limiting hyperinsulinaemia and hypoglycaemia have been described in neonates born to mothers taking ritodrine therapy for premature labour. Ritodrine crosses the placental barrier and enters the fetal circulation readily but the mechanism of how it causes hyperinsulinaemia and hypoglycaemia is unclear. We report the case of severe prolonged hyperinsulinaemic hypoglycamia in a neonate born to a mother taking ritodrine therapy from 16 weeks' gestation for preterm labour. The hyperinsulinaemic hypoglycaemia was managed with oral nifedipine as diazoxide was contraindicated due to fluid overload. Possible mechanisms of ritodrine-induced hypoglycaemia and insulin secretion are discussed.

Are maternal hypertension and small-for-gestational age risk factors for severe intraventricular hemorrhage and cystic periventricular leukomalacia? Results of the EPIPAGE cohort study.

OBJECTIVE: The purpose of this study was to examine the relationships between different causes of preterm delivery (eg, maternal hypertension, small-for-gestational age [SGA], other) and cerebral damage (eg, cystic periventricular leukomalacia [c-PVL], grade III intraventricular hemorrhage [IVH], and intra-parenchymal hemorrhage [IPH]). STUDY DESIGN: This study included 1902 very preterm singletons who were transferred to neonatal intensive care units in 9 French regions. We used logistic regression models to compare the risk of cerebral injury associated with maternal hypertension, SGA, and all other causes of preterm delivery. RESULTS: We found that the risk of c-PVL and grade III IVH was higher in infants born after preterm premature rupture of membranes (PPROM) with short latency or idiopathic preterm labor than in infants born to hypertensive mothers. We show that SGA and antepartum maternal hemorrhage significantly increase the risk of IPH. CONCLUSION: Our results show that infants born to hypertensive mothers have a lower risk of cerebral injuries than infants born following idiopathic preterm labor and PPROM because they are less exposed to prenatal infection.

Predictors of vaginal bleeding during the first two trimesters of pregnancy.

This study evaluates maternal age, race, cigarette smoking, prior spontaneous abortion, prior induced abortion, and prior preterm birth in relation to vaginal bleeding during the first two trimesters of pregnancy. Information on vaginal bleeding and predictors came from the Pregnancy, Infection, and Nutrition Study, which enrolled 2806 pregnant women at 24-29 weeks' gestation during 1995-2000 in central North Carolina, USA. Generalised estimating equations were applied to take into account repeated episodes of vaginal bleeding during pregnancy. Women with advanced maternal age and passive smoking exposure were more likely to experience more intense vaginal bleeding during pregnancy, as were women with prior preterm birth. More intense bleeding was also more likely to be reported among women with multiple prior spontaneous abortions or multiple prior induced abortions, but not among women with a single prior spontaneous or induced abortion. The combination of prior spontaneous and induced abortion showed a dose-response association with the occurrence of vaginal bleeding during pregnancy.

Sonographic measurement of cervical length in threatened preterm labor in singleton pregnancies with intact membranes.

OBJECTIVES: To predict when delivery will occur, within 48 h and 7 days of presentation and before 35 weeks' gestation in women presenting with threatened preterm labor. METHODS: Sonographic measurement of cervical length was carried out in 510 women with singleton pregnancies presenting with threatened preterm labor and intact membranes at 24 to 33 + 6 weeks of gestation. The measurement was not taken into account in the subsequent management of the pregnancies. The outcome measures were delivery within 48 h and 7 days of presentation and delivery before 35 weeks. RESULTS: The median gestation at presentation was 30 + 1 (range, 24 to 33 + 6) weeks and the median cervical length was 25 (range, 1-51) mm. Delivery within 48 h of presentation occurred in 21 (4.1%) cases, delivery within 7 days occurred in 43 (8.4%) and delivery before 35 weeks occurred in 76 (14.9%). Logistic regression analysis demonstrated that the only significant independent predictor of delivery within 48 h was cervical length (odds ratio (OR), 0.73; 95% CI, 0.65-0.81) and for delivery within 7 days the independent predictors were cervical length (OR, 0.69; 95% CI, 0.63-0.76) and vaginal bleeding (OR, 19.42; 95% CI, 3.87-97.4). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such delivery was cervical length (OR, 0.92; 95% CI, 0.88-0.96, P < 0.0001). There was no significant independent contribution to any of the outcome measures from ethnic group, maternal age, gestational age, body mass index, parity, cigarette smoking or use of tocolytics. CONCLUSIONS: In women with threatened preterm labor sonographic measurement of cervical length helps to distinguish between true and false labor and to predict early preterm delivery.

Ruptura prematura de membranas / Premature rupture of the membranes

A ruptura prematura de membranas ovulares (ruprema) acomete, aproximadamente, 8 por cento das gestações. Associa-se a um elevado índice de complicações materno-fetais, especialmente as infecciosas, requerendo diagnóstico preciso, assim como adequada terapêutica. Os autores fazem uma revisão sobre ruprema, abordando os principais aspectos a este tema relacionados

Developmental lag in superoxide dismutases relative to other antioxidant enzymes in premyelinated human telencephalic white matter.

Periventricular leukomalacia (PVL) involves free radical injury to developing oligodendrocytes (OLs), resulting from ischemia/reperfusion, particularly between 24 and 32 gestational weeks. Using immunocytochemistry and Western blots, we tested the hypothesis that this vulnerability to free radical toxicity results, in part, from developmental lack of superoxide dismutases (SOD)-1 and -2, catalase, and glutathione peroxidase (GPx) in the telencephalic white matter of the human fetus. During the period of greatest PVL risk and through term (> or = 37 weeks), expression of both SODs (for conversion of O2- to H2O2) significantly lagged behind that of catalase and GPx (for breakdown of H2O2), which, in contrast, superseded adult levels by 30 gestational weeks. Our data indicate that a developmental "mismatch" in the sequential antioxidant enzyme cascade likely contributes to the vulnerability to free radical toxicity of the immature cerebral white matter, which is "unprepared" for the transition from a hypoxic intrauterine to an oxygen-rich postnatal environment. All enzymes, localized to astrocytes and OLs, had higher-than-adult expression at 2 to 5 postnatal months (peak of myelin sheath synthesis), suggesting an adaptive mechanism to protect against lipid peroxidation during myelin sheath (lipid) synthesis. The previously unrecognized dissociation between the expression of the SODs and that of catalase and GPx in the fetal period has potential implications for future antioxidant therapy in PVL.

Expression of connexin 26 in the ganglionic eminence of preterm infants after bleedings.

The ganglionic eminence being a prominent part of the telencephalic proliferative zone is the most common site of bleedings in preterm infants. This immunohistochemical study demonstrates that connexin 26 involved in forming intercellular gap junctions is expressed in ganglionic eminence cells up to 500 microm from the bleeding. In controls, no positive cells are present. It is discussed that an increase of gap junctional communication may result in spreading of the primary injury.

[Maternal risk factors and premature birth in a public hospital at west of Mexico]. / Factores de riesgo materno y nacimiento pretérmino en un hospital público del occidente de México.

OBJECTIVE: To identify the maternal risk factors associated with preterm birth. MATERIAL AND METHOD: A case-control study of 158 preterm birth and 158 term newborns, was done from September to December 2002 in the Hospital Civil Dr. Juan I. Menchaca. Gestational age was determined with Capurro simplified method in > 29 week-babies and with last menstruation date in < 29 week-cases. The exposure was documented by a direct interview to the mother and clinical information of the clinical expedient. The association was measured with the odds ratios and confidence interval of 95%. RESULTS: The frequency of preterm birth was of 3.4 percent of newborn alive, mortality was of 13%. The maternal risk factors associated with preterm birth were: multiple birth (OR: 12.61, IC 95: 3.6-53.0), illnesses during pregnancy (OR: 12.61, IC 95%: 3.6-53.0), premature rupture of amniotic membranes (OR: 7.06, IC 95%: 3.5-14.6), inadequate prenatal care (OR: 4.07, IC 95%: 2.1-7.8), urinary tract infections (OR: 3.20, IC 95%: 1.7-6.2), cervicovaginitis (OR: 2.45, IC 95%: 1.4-4.3) and low socioeconomic level (OR: 1.92, IC 95%: 1.2-3.1). CONCLUSIONS: The association of maternal risk factors with preterm birth requires more study with special design.

Maintenance therapy with calcium channel blockers for preventing preterm birth after threatened preterm labour.

BACKGROUND: Calcium channel blocker maintenance therapy is one of the types of tocolytic therapy used after an episode of threatened preterm labour (and usually an initial dose of tocolytic therapy) in an attempt to prevent the onset of further preterm contractions. OBJECTIVES: To assess the effects of calcium channel blockers as maintenance therapy on preventing preterm birth after threatened preterm labour. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (31 March 2004); MEDLINE (1966 to March 2004) and DARE (June 2003). SELECTION CRITERIA: Randomised controlled trials of calcium channel blockers used as maintenance therapy to prevent preterm birth after threatened preterm labour, compared with alternative drug therapy, placebo or no treatment. DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the selection criteria, extracted data from the included study and assessed study quality. MAIN RESULTS: One trial of 74 women was included. No difference in the incidence of preterm birth was found when calcium channel blocker (nifedipine) maintenance therapy was compared with no treatment. Twenty-five women out of 37 in each group gave birth before 37 weeks (relative risk 1.00, 95% confidence interval 0.73 to 1.37). The trial did not report stillbirths and neonatal deaths prior to discharge. Neurological follow up of the infants was not addressed. REVIEWERS' CONCLUSIONS: The role of maintenance therapy with calcium channel blockers for preventing preterm birth is not clear. Well designed randomised trials of sufficient size with relevant outcomes are required.

W(h)ither the deaf community? Population, genetics, and the future of Australian sign language.

According to enrollments in schools for the deaf and data from the national census and neonatal hearing screening programs, the incidence of severe and profound childhood deafness in Australia is, and has been, less than commonly assumed. Factors implicated include improved medical care, mainstreaming, cochlear implants, and genetic science. Data for the United States, Britain, and other developed countries seem consistent with those for Australia. Declining prevalence and incidence rates have immediate implications for sign-based education, teacher-of-the-deaf training programs, and educational interpreting. There are also serious consequences for research, documentation, and teaching regarding Australian Sign Language (Auslan), and for the future viability of Auslan. Prompt action is essential if a credible corpus of Auslan is to be collected as the basis for a valid and verifiable description of one of the few native sign languages in the world with significant attested historical depth.

Deep tendon reflexes, magnesium, and calcium: assessments and implications.

The perinatal nurse, in collaboration with physicians, can use deep tendon reflexes as a powerful tool in determining the need to start, adjust, or stop magnesium infusion. Toxicity can be detected using physical manifestations as a guide. Clinical signs may be a better indicator than serum levels of tissue levels of magnesium. Whether magnesium is given to prevent seizures or for tocolysis, patients in both situations are at risk for developing toxicity and must be assessed regularly to ensure patient safety.

Is pre-eclampsia more than one disease?

OBJECTIVES: The clinical characteristics of pre-eclampsia (gestational hypertension and proteinuria) may represent separate pathogenetic conditions. Pre-eclampsia accompanied by restricted fetal growth may originate from abnormal implantation, and appropriate or high birthweights may indicate a mixture of conditions, ranging from mild pre-eclampsia with modest placental involvement to hypertensive conditions without placental disease. DESIGN: Prospective, observational study. SETTING: General population. POPULATION: We used data from the Medical Birth Registry of Norway, a population-based registry that has recorded births since 1967. For this study, we used information on length of gestation and presence of pre-eclampsia among 1,679,205 singletons born between 1967 and 1998. Pre-eclampsia was diagnosed in 44,220 (2.6%) pregnancies. METHODS: We studied the risk of pre-eclampsia in relation to standardised measures (z scores) of birthweight, adjusted for length of gestation, and stratified by term and preterm delivery. We also explored whether gestational diabetes was more prevalent in conjunction with preterm than term pre-eclampsia. MAIN OUTCOME MEASURES: Pre-eclampsia diagnosed at term or preterm. RESULTS: For pre-eclampsia diagnosed around term, there was a U-shaped association with birthweight. Compared with appropriate birthweights for gestation, the risk of term pre-eclampsia was more than fourfold higher (relative risk [RR] 4.5, 95% confidence interval [CI], 4.3 to 4.7) if the baby's birthweight was lower than two standard deviations under the mean. For birthweights three standard deviations or higher than the mean, pre-eclampsia was more than twice as likely (RR 2.6, 95% CI 2.2-2.9). In contrast, the risk of preterm pre-eclampsia displayed an L-shaped association with birthweight. Low birthweight (less than -2 standard deviations) was associated with greatly increased risk (RR 9.9, 95% CI 9.1-10.9), but for high birthweights (>or=3 standard deviations), there was no association with the risk of preterm pre-eclampsia (RR 1.2, 95% CI 0.7-2.1). The prevalence of gestational diabetes was three times (prevalence ratio 3.3, 95% CI 2.6-3.6) higher in preterm than term pre-eclampsia. CONCLUSION: Whereas pre-eclampsia with preterm delivery associated with low birthweight may be caused by underlying placental abnormality, pre-eclampsia delivered at term may represent a mixture of conditions, ranging from mild pre-eclampsia with moderate placental affection to hypertensive conditions in pregnancy without placental dysfunction.

An investigation into the association among preterm birth, cytokine gene polymorphisms and periodontal disease.

OBJECTIVE: To investigate a putative relationship between preterm delivery and the carriage of polymorphic genes that code for the cytokines interleukin-1beta (IL-1beta) at codon +3953 and tumour necrosis factor-alpha (TNF-alpha) at codon -308 in a group of postpartum women and to elucidate if the concurrent presence of periodontal disease increased the risk of preterm delivery in this group. DESIGN: Case-control study SETTING: Postnatal wards at Guy's and St Thomas' Hospital Trust. POPULATION: Postpartum women from southeast London, UK. METHODS: Case subjects were defined as those who experienced a birth at less than 37 weeks of gestation. Control subjects gave birth at term. Demographic data were collected and a periodontal examination was performed. Blood samples were collected and analysed by restriction fragment length polymerase techniques for the presence of each of the allelic variants. MAIN OUTCOME MEASURES: The level of periodontal disease and the carriage of allelic variants of IL-1beta+3953 and TNF-alpha-308 genes. RESULTS: Forty-eight case subjects and 82 control subjects were assessed. There was no statistically significant difference in the carriage of the IL-1beta+3953 allelic variant between cases and controls (29%versus 18%, P= 0.112). However, 23 (48%) of the case subjects and 24 (29%) of controls were heterozygous or homozygous for the variant TNF-alpha-308 gene (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.0-5.0, P= 0.026). There was no association between the carriage of either the polymorphic IL-1beta+3953 or TNF-alpha-308 variant and the severity of periodontal disease. The combination of periodontal disease and the allelic variant did not increase the risk of preterm delivery. CONCLUSIONS: In this study, a higher proportion of women who delivered preterm carried the polymorphic TNF-alpha-308 gene. There did not appear to be any interaction between either of the genotypes and periodontal disease with preterm delivery as has been reported for bacterial vaginosis and the TNF-alpha-308 polymorphic gene.

[Preterm labour and risk factors]. / Frühgeburt und Risikofaktoren.

Infections, stress and haemorrhages are risk factors in the pathophysiology of preterm delivery. Genital infections can be diagnosed and treated, and thus the frequency of preterm labour is lowered. How psychosocial burdens which are also stress factors can be influenced remains uncertain.

Fisiopatología de la rotura prematura de las membranas ovulares em embarazos de pretérmino / Physiopathology of the premature rupture of membranes in preterm pregnancies

Se revisa la información de la literatura respecto de la estructura de las membranas ovulares, describiendo la zona de morfología alterada extrema, los mecanismos fisiopatológicos involucrados en la rotura prematura de membranas (destacando el proceso de apoptosis), relacionados a infección, isquemia placentaria, distensión de membranas, hemorragia coriodecidual, tabaquismo, relaxina, prolactina, hormona paratiroídea.

Prematuridade como possível fator influenciador do controle da cabeça / Prematurity as possible influence factor on the postural control of the head

Um controle postural estável constitui a base para a organização e execução voluntária do movimento. Este é exteriorizado através da emergência de habilidades motoras como, por exemplo, o controle da cabeça. Partos prematuros são eventos patológicos e gram muitos riscos para a criança, pois o desenvolvimento rápido e íntegro do seu sistema nervoso central, resposável pela motricidade voluntária, pode ser comprometido. O objetivo desse estudo foi comparar o controle de cabeça entre as crianças pré-termo e a termo. Para tal, analisou-se vídeo-registros de cinco crianças pré-termo e cinco a termo, aos dois e quatro meses de idade, incluídas em um Programa de Acompanhamento do desenvolvimento Motor em crianças pré-termo, do departamento de Fisioterapia do Hospital Universitário do Norte do Paraná, da Universidade Estadual de Londrina. Foram avaliados os itens relacionados com a aquisição do controle de cabeça da avaliação Gross Motor Fuction Measurement (GMFM). Através dessa análise, observou-se uma diferença de pontuação entre o grupo das crianças pré-termo e a termo. No entanto, estes valores não foram significativos ao serem analisados estatísticamente pelo teste t de stuedent. Por meio dos resultados obtidos neste estudo, pode-se sugerir que a prematuridade não é um fator influenciador do controle de cabeça final e que apesar de um ligeiro atraso do desenvolvimento da aquisição do controle de cabeça das crianças pré-termo, ao final dos quatro meses de idade, ambos os grupos apresentavam pontuações similares...

Antibiotic use and preterm labor: attitudes and practice patterns of North Carolina obstetric providers.

BACKGROUND: Despite the reported link between subclinical genital tract infection (GTI) and preterm labor (PTL), it is not certain that treating PTL empirically with antibiotics decreases neonatal morbidity and mortality. This study describes the beliefs of family physicians and nurse-midwives regarding the link between subclinical GTI and PTL and their use of empiric antibiotics to treat spontaneous PTL. METHODS: This was a survey of family physicians, family practice residents, and midwives (n = 588) who practice obstetrics in North Carolina. The response rate was 61%. RESULTS: Ninety-six percent of providers search for GTI, and 76% believe antibiotics for presumed infection will benefit the neonate. Wide variation in the use of antibiotics exists within groups and between groups of providers. Nurse-midwives are more likely than family physicians to use broad-spectrum antibiotics (p < 0.001). CONCLUSIONS: Family physicians and nurse-midwives are uncertain about the optimal management of PTL. Empiric antibiotic use varies widely despite the lack of supportive data.

Obstetric and gynecologic complications in women with Marfan syndrome.

OBJECTIVE: To analyze the maternal and fetal outcomes of pregnancy and gynecologic problems in women with Marfan syndrome. STUDY DESIGN: The outcomes of 14 pregnancies in 4 women with Marfan syndrome were prospectively observed between January 1988 and December 2000. The cardiovascular and obstetric complications were analyzed. During pregnancy all the patients were carefully monitored with serial echocardiography and close attention to symptoms. RESULTS: Of the 14 pregnancies, 5 (35.7%) ended in abortion, and 3 of them occurred in the early second trimester due to cervical incompetence. Premature onset of labor occurred in 2 pregnancies at 31 and 34 weeks. Postpartum hemorrhage complicated 3 deliveries, and inversion of the uterus occurred in 1 patient. Significant cardiovascular complications occurred in 2 patients, who required surgical correction of the aortic aneurysm and replacement of the aortic valve. In one patient the operation was performed within hours of vaginal delivery, and the other patient underwent surgery 8 weeks postpartum. No maternal death occurred in the study. One infant in the series was diagnosed as having Marfan syndrome. A premature infant delivered at 31 weeks died on the second day of life. CONCLUSION: Women with Marfan syndrome are at high risk of aortic dissection in pregnancy even in the absence of preconceptional aortic root dilatation. Obstetric complications in patients with this condition have been underreported in the past. Women with aortic root dilatation of < 40 mm usually tolerate pregnancy well, with good maternal and fetal outcomes. Women with Marfan syndrome should be counseled regarding the risk of pregnancy to both mother and fetus. Patients who have cardiac decompensation or aortic dilatation > 40 mm are advised to avoid pregnancy.

Preterm birth, birth weight, and subsequent risk of female breast cancer.

We have previously found an increased risk of breast cancer among women born preterm. To confirm or refute the results, an enlarged study was conducted. The results from this study do not confirm the initial findings and suggest that preterm birth can be ruled out as a risk factor for breast cancer.