Desarrollo evolutivo infantil, patología obstétrica y repercusión sociofamiliar en nacidos antes de la semana 29 / Child development, obstetrice abnormalities and social and familial repercussions in infants born at less than 29 weeks’ gestation

Objetivos: Conocer el futuro infantil de nacidoscon edad gestacional inferior a 29 semanas y susimplicaciones obstétricas y sociofamiliares.Material y métodos: Estudio retrospectivo de 28niños, nacidos antes de la semana 29, derivados alPrograma de Atención Temprana del Gobierno deCantabria, entre enero de 2002 y junio de 2006.Resultados: Las causas de prematuridad másfrecuentes de este grupo son: corioamnionitis,desprendimiento prematuro de placenta normoinserta y amenaza de parto pretérmino. Un 28,57% de los niños estudiados presentan una minusvalía: retraso mental grave y parálisis cerebral infantil (37%); retraso mental moderado (24%) y, en los casos restantes, hipoacusia moderada bilateral, alteraciones respiratorias y retraso mental leve. Las principales consecuencias sociales son: la transformación de roles en la familia, la repercusión económica negativa y la gran carga emocional.Conclusiones: Un 28,57% de estos niños presentan una minusvalía documentada; no hay una patología obstétrica determinante, pero las consecuencias sociofamiliares son muy importantes

Objectives: To determine the outcomes of infantsborn at less than 29 weeks’ gestation, obstetricabnormalities, and the social and familialrepercussions of this prematurity.Material and methods: We retrospectively studied28 infants, born at less than 29 weeks’ gestation,referred to the Early Healthcare Program of theCantabrian Government between January 2002 andJune 2006.Results: The main causes of prematurity in thisgroup were chorioamnionitis, placental abruption,and preterm labor. Of the infants studied, 28.57%had a disability. Severe mental retardation andcerebral palsy was found in 37% and moderatemental retardation in 24%. Bilateral hypacusis,respiratory alterations and mild mental retardationwere found in the remainder. The main socialrepercussions were a change in family roles,negative economic effects, and heavy emotionalburden.Conclusions: A total of 28.57% of the infantsstudied had a recognized disability. No predominant obstetric abnormality was identified. However, the social and familial repercussions were substantial (AU)

Síndrome de Goldenhar. Manifestaciones intraútero y tras nacimiento / Goldenhar syndrome. Intrauterine and postnatal features

El síndrome de Goldenhar fue descrito por primera vez en 1952 por Maurice Goldenhar como la asociación entre diferentes anomalías de la región facial, frecuentemente oculares y auriculares. Debido a la complejidad de sus manifestaciones, es conocido como displasia óculo-aurículo-vertebral (AU)

Goldenhar syndrome was first described in 1952 by Maurice Goldenhar as the association of various facial anomalies. The most frequent anomalies are ocular and auricular. Due to the complexity of its manifestations, this syndrome is also known as oculo-auriculo-vertebral dysplasia (AU)

Repercusión del parto pretérmino / Out comes of preterm parturition

Se realizó un estudio prospectivo descriptivo en el hospital Ginecobstétrico Provincial Docente Ana Betancourt de Mora de Camagüey para determinar la repercusión del parto pretérmino desde enero a diciembre del año 2004. El universo estuvo constituido por las gestantes que tuvieron este evento entre 21 y 36.6 semanas; en total fueron 197 embarazadas, con edad media de 26.4 +/- 6.4 años; de las cuales 101 para el 51.2 por ciento, no tenían experiencia previa de parto, 89 fueron evaluadas como bajo peso (45.1 por ciento) y 119 con ganancia insuficiente (60.4 por ciento). La infección vaginal fue la enfermedad asociada más frecuente, al constituir el 41.6 por ciento de la muestra y la rotura prematura de membranas la propia con 108 para el 54.8 por ciento. La mayor cantidad de partos ocurrió después de las 33 semanas con 138 para un 70 por ciento. La depresión respiratoria transitoria con 55 (27.9 por ciento), la neumonía congénita 23 (11.6 por ciento) y la enfermedad de la membrana hialina 22 (11.1 por ciento) constituyó la principal morbilidad de los neonatos; mientras que la anemia con 11 (5.5 por ciento) y la dehiscencia de la rafia con 6 (0.3 por ciento) las maternas. Se confirmó la necesidad del estudio y control de los factores de riesgo del parto pretérmino como la infección cervicovaginal que tan elevada morbilidad puede causar a nuestras mujeres en general y particularmente a los gestantes con su secuela de bajo peso al nacer e inmadurez secundaria a la prematuridad, ya sea directamente o través de la rotura prematura de las membranas amnióticas(AU)

El parto prematuro: la emboscada en la preparación maternal / Premature labour: the ambush in maternal education

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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.

Asociación entre las infecciones del tracto urinario y el parto pretérmino / Association between urinary tract infections and preterm birth

Objetivo: Valorar si los partos pretérmino se asocian a mayor incidencia de infecciones del tracto urinario (ITU) que los partos a término. Diseño: Estudio retrospectivo de casos y controles. Emplazamiento: Servicio de Ginecología y Obstetricia del Hospital Universitario Central de Asturias. Participantes: Grupo estudio: 60 gestantes con parto antes de la 37 semana. Grupo control: 37 gestantes que dieron a luz a término. En ambos casos se descartaron todas las causas conocidas de parto pretérmino, salvo las relacionadas con ITU. Mediciones principales: Variables analizadas: edad, paridad, ITU sintomática, infecciones genitales durante la gestación, edad gestacional en el primer episodio de amenaza de parto pretérmino y en el parto, tipo de parto y complicaciones perinatales. Se realizó un estudio descriptivo y comparativo de ambos grupos. Resultados: El 50% de las gestantes del grupo estudio presentaban ITU frente al 18,9% del grupo control (p = 0,002). El 83,3% de los recién nacidos del grupo estudio presentaron complicaciones perinatales frente al 5,4% en el grupo control (p = 0,000). No se encontraron diferencias estadísticamente significativas entre ambos grupos en infecciones vaginales ni en vía de parto.Conclusiones: Los partos pretérmino sin otro factor de riesgo conocido se asocian a mayor incidencia de ITU

Objective: To evaluate whether preterm birth is associated with a greater incidence of urinary tract infection (UTI) than term births. Design: Retrospective case-control study. Setting: Gynecology and Obstetrics Service of the Central University Hospital of Asturias (Spain). Participants: Sixty pregnant women who gave birth before week 37. Control group: 37 pregnant women who had term deliveries. In both groups, all known causes of premature birth were ruled out except those related to UTI. Main measurements: The variables analyzed were age, parity, symptomatic UTI, genital infections during pregnancy, gestational age in the first episode of risk of premature delivery, type of delivery, and perinatal complications. A descriptive, comparative study of both groups was performed. Results: UTI was found in 50% of pregnant women in the study group compared with 18.9% of those in the control group (p = 0.002). Perinatal complications were found in 83.3% of neonates in the study group versus 5.4% of those in the control group (p = 0.000). No significant differences between the two groups were found in vaginal infections or delivery route. Conclusions: Preterm birth without other known risk factors is associated with a greater incidence of UTI

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.

Resultados perinatales en gestaciones triples. Estudio de 90 casos / Perinatal results in triplet gestations. A study of 90 cases

Objectives. To analyze the perinatal results of 90 triplet pregnancies attended in the Hospital de Cruces (Vizcaya) during the last 15 years. Material and methods. From January 1989 until December 2003 there were a total of 78 566 deliveries, of which 90 were triplets. We make a retrospective study of these pregnancies. Results. The incidence of triplet pregnancies has increased noticeably in recent years, increasing from 0.5 ‰ in 1989 to 3 ‰ in 2002. The main complication of these pregnancies was pre-term labour (45.6%), with an average hospital admission of 12.4 ± 13.9 days (range 1-60 days). Mean gestational age at delivery was 34 ± 2.9 weeks, with a pre-maturity level of 86.6%. The average weight of the newborns was 1795 ± 506, 1890 ± 513 and 1795 ± 517 grams respectively for the first, second and third fetus. Of the newborns, 6.28% weighed less than 1000 grams. All cases of perinatal mortality (18.5%) were in this group of newborns who weighed less than 1000 grams. Conclusion. The level of pre-maturity is the main complication to remember when making any prognostic on triplet pregnancies, and is the main influence for perinatal results (AU)

Objetivos. Analizar los resultados perinatales de los 90 embarazos triples atendidos durante los últimos 15 años en el Hospital de Cruces (Vizcaya). Material y métodos. Desde enero de 1989 hasta diciembre de 2003 se ha atendido un total de 78.566 partos. De ellos, 90 fueron partos triples. Estudiamos de forma retrospectiva los resultados perinatales de estos embarazos. Resultados. La incidencia de embarazos triples se ha incrementado notablemente en los últimos años, que pasó del 0,5‰, en 1989, al 3‰, en 2002. La principal complicación de estas gestaciones fue la amenaza de parto pretérmino (45,6%), con un tiempo medio de hospitalización por este proceso de 12,4 ± 13,9 días (rango, 1-60 días). La edad media en el momento del parto fue de 34 ± 2,9 semanas, con una tasa de prematuridad del 86,6%. El peso medio de los recién nacidos fue de 1.795 ± 506, 1.890 ± 513 y 1.795 ± 517 g, respectivamente, para el primero, segundo y tercer feto. El 6,28% de los recién nacidos nació con un peso inferior a 1.000 g. Todos los casos de mortalidad perinatal (18,5‰) se centraron en este grupo de recién nacidos de peso < 1.000 g. Conclusión. La tasa de prematuridad es la principal complicación a tener en cuenta a la hora de dar un pronóstico a los embarazos triples y la que más condiciona los resultados perinatales (AU)

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.

Relación entre enfermedad periodontal y parto prematuro. Bajo peso al nacimiento: una revisión de la literatura / The relationship between periodontal disease and preterm low birth weight: a literature review

A pesar de los esfuerzos realizados en el control del embarazo y el parto, la frecuencia de los partos prematuros no ha disminuido en las dos últimas décadas. El parto prematuro supone una seria amenaza para la salud del recién nacido, y representa además un porcentaje muy importante de los costes destinados a la atención sanitaria perinatal. La investigación científica ha revelado diversos mecanismos por los que infecciones remotas como la enfermedad periodontal pueden participar en la patogenia del parto prematuro. Estudios recientes han demostrado que la enfermedad periodontal es un factor de riesgo para el parto prematuro, habiéndose hallado un riesgo relativo mayor que el calculado para factores de riesgo tradicionales como el tabaquismo, bajo peso materno o consumo de alcohol. Se ha sugerido que la prevención y el tratamiento de la enfermedad periodontal en mujeres gestantes podrían contribuir a la prevención del parto prematuro. En el presente artículo revisamos la evidencia científica presente en la literatura acerca de esta asociación y del papel del tratamiento periodontal en la prevención del parto prematuro (AU)

Despite all efforts made for pregnancy and labour care, the incidence of preterm births has not decreased in the last two decades. Prematurity implies a serious threat to the health of the newborn, representing an important percentage of the perinatal health care costs. Scientific research has revealed multiple mechanisms through which remote infections such as periodontal disease can participate in the pathogenesis of preterm birth. Recent studies have demonstrated that periodontal disease is a risk factor for preterm birth, even with higher odds ratios than those calculated for traditional risk factors such as tobacco consumption, low maternal weight or alcohol consumption. It has be en suggested that the prevention and treatment of periodontal disease in pregnant women could contribute to the prevention of preterm birth. This paper reviews the scientific evidence in the literature regarding this asociation and the role of periodontal therapy in preventing preterm birth (AU)

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.