El prematuro tardío, ¿qué sabemos desde el punto de vista perinatal? / The late premature, what do we know from the perinatal point of view?

Resumen El parto prematuro es la principal causa de morbimortalidad neonatal en Chile. Los prematuros tardíos, definidos como nacimientos entre 34 semanas con 0 días (34+0) y 36 semanas con 6 días (36+6) de gestación, representan el 70-80% de los prematuros y se asocian a baja morbilidad y excepcional mortalidad si se comparan con partos bajo 34 semanas, pero significativamente mayor al compararlos con partos de término. Los prematuros tardíos son el resultado de diversas condiciones obstétricas, tales como síndromes hipertensivos del embarazo, rotura prematura de membranas, colestasia intrahepática del embarazo y comorbilidad médica. El propósito de esta revisión es actualizar la información asociada a los prematuros tardíos y dar una visión de las tendencias en el uso de corticoides y el manejo expectante de la rotura prematura de membranas con el objetivo de disminuir las complicaciones en este grupo de prematuros.

Abstract Preterm delivery is the most important cause of neonatal morbidity and mortality in Chile. Late preterm, defined as deliveries between 34 +0 and 36+6-weeks accounts for 70-80% of preterm and is associated with non-severe morbidity and extremely low mortality when compared with deliveries below 34 weeks but significantly high when compared with full term babies. Late preterm deliveries are a result of several obstetric conditions, such a hypertensive disorder, premature rupture of membranes, intrahepatic cholestasis, and maternal medical comorbidities. The purpose of this review is to update the information associated with the risks of late preterm and to guide in the new trends in the application of steroid and expectant management for premature rupture of membranes in order to reduce the frequency of late preterm.

First trimester screening for preterm and term pre-eclampsia by maternal characteristics and biophysical markers in a low-risk population.

AIM: To develop a combined predictive model for preterm and term pre-eclampsia (PE) during the first trimester of pregnancy. METHODS: This investigation was a nested case-control study in singleton pregnancies at the Maternal-Fetal Medicine Unit, University of Chile Hospital. A priori risks for preterm and term PE were calculated by multivariate logistic regression analyses. Biophysical markers were log10 -transformed and expressed as multiples of the median. A multivariate logistic regression analysis was used to estimate a combined predictive model of preterm and term PE. Detection rates at different cut-off points were determined by a receiver operator curve analysis of a posteriori risks. RESULTS: First trimester mean arterial pressure and uterine artery Doppler pulsatility index were significantly higher in women who develop PE than in the unaffected group. The detection rate of preterm PE based on maternal characteristics and biophysical markers was 72% at a 10% false-positive rate, corresponding to a cut-off risk of 1 in 50. The detection rate for term PE was 30% at a 10% false-positive rate. CONCLUSION: Preterm PE can be predicted by a combination of maternal characteristics and biophysical markers. However, first trimester screening is less valuable for term PE.

Anti-Müllerian hormone in type 2 and gestational diabetes during the second half of pregnancy: relationship with sexual steroid levels and metabolic parameters.

Hyperandrogenemia and hyperinsulinemia are observed in women with diabetes during pregnancy. The effect of diabetes on anti-Müllerian hormone (AMH) levels during pregnancy is unclear. The aim of this study was to determine the AMH levels in women with type 2 diabetes (T2D) and gestational diabetes (GD) compared to healthy (C) pregnant women during the second half of gestation. A prospective study of 69 pregnant women with T2D (N: 21), GD (N: 24) and C (N: 24) were followed up during the second half of pregnancy. Clinical assessments and blood samples were collected at 26.7 (25-27.8); 34 (32-34.9) and 37.5 (37-40) weeks of gestation. AMH, sexual steroids, insulin, homeostatic model assessment of insulin resistance, HbA1c levels were measured. AMH levels were similar between T2D, GD and C (p = .07). A decline of AMH levels during the second half of gestation was observed in the three groups (p < .0001). AMH levels were negatively associated with age (p < .001). A positive association between AMH and testosterone (p < .05) was found in all groups. A progressive decline of AMH levels is observed in diabetic and healthy women during the second half of pregnancy. Testosterone levels are an independent factor that influences AMH levels during pregnancy. However, AMH levels are not affected by the presence of diabetes during gestation.

Pregestational type 2 diabetes and gestational diabetes exhibit different sexual steroid profiles during pregnancy.

Higher androgen levels are observed in non-pregnant women with diabetes. Whether this hormonal profile is found during pregnancy is unknown. The aim of this study was to determine the sexual steroids levels in pregnant women with pregestational type 2 (T2D) and gestational diabetes (GD) compared to healthy control (C) pregnant women during the second half of pregnancy. A prospective study of 69 pregnant women with T2D (n = 21), GD (n = 24) and control (C, n = 24) was followed up during the second half of gestation. Clinical assessments and blood samples were collected at 26.7 (25-27.8); 34 (32-34.9) and 37.5 (37-40) weeks of gestation. Androgens, sex hormone-binding globulin (SHBG), estrogens, estradiol/testosterone (E/T) ratio, insulin, glucose, HOMA-IR, were measured. Testosterone, insulin and homeostatic model assessment of insulin resistance (HOMA-IR) levels were higher in T2D compared with C at each sampling point during pregnancy, even after adjusting for BMI and age. Estrogens levels and estradiol/testosterone ratio were lower in T2D and GD compared with C. Hyperandrogenemia, and higher insulin resistance is observed in T2D, but not in GD during pregnancy. Decreased estrogen and E/T ratio found in T2D and GD suggests a diminished aromatase activity during gestation. T2D and GD are associated with specific changes in sexual steroids and insulin resistance levels during pregnancy.

[Risk factors for preterm deliveries in a public hospital]. / Factores asociados con el parto prematuro entre 22 y 34 semanas en un hospital público de Santiago.

BACKGROUND: Preterm births are responsible for 75 to 80% of perinatal mortality. AIM: To determine the factors associated with preterm births, using maternal clinical data, laboratory results and pathological placental findings. PATIENTS AND METHODS: Retrospective study of 642 preterm single births at 22-34 weeks' gestation. Four hundred and seven cases with pathological placental studies were included. Births were subdivided into preterm births as a consequence of a medical indication and spontaneous births with or without premature rupture of membranes (PROM). Risk factors for preterm births were classified as maternal, fetal, placental, indeterminable and unclassifiable. RESULTS: The proportions of preterm births were spontaneous 69% (with PROM 27% and with intact membranes 42%) and medically indicated births 31%. A risk factor associated with prematurity was identified in 98 and 85% of medically indicated and spontaneous births, respectively. Ascending bacterial infection (ABI) was the most frequently associated factor with spontaneous preterm delivery in 51% of women (142/280, p < 0.01) and with preterm births of less than 30 weeks in 52% of women (82/157, p < 0.01). Vaginal or urinary infection with Group B Streptococcus, was the most common clinical condition associated with ABI related deliveries. Hypertension was present in 94 of 127 medically indicated preterm deliveries (preeclampsia in 62% and chronic hypertension in 12%), and in 29% (preeclampsia 24%) of preterm births of more than 30 weeks. Congenital anomalies were mainly associated with a maternal age over 35 years in 15% (14/92) of women. The frequency of placental diseases was higher in spontaneous preterm deliveries (14%) and in pregnancies of more than 30 weeks in (14%). CONCLUSIONS: ABI was the most common factor associated with spontaneous preterm births at 2234 weeks, while preeclampsia is the most common factor associated with medically indicated preterm births.

Factores asociados con el parto prematuro entre 22 y 34 semanas en un hospital público de Santiago / Risk factors for preterm deliveries in a public hospital

Background: Preterm births are responsible for 75 to 80% of perinatal mortality. Aim: To determine the factors associated with preterm births, using maternal clinical data, laboratory results and pathological placental findings. Patients and Methods: Retrospective study of 642 preterm single births at 22-34 weeks' gestation. Four hundred and seven cases with pathological placental studies were included. Births were subdivided into preterm births as a consequence of a medical indication and spontaneous births with or without premature rupture of membranes (PROM). Risk factors for preterm births were classified as maternal, fetal, placental, indeterminable and unclassifiable. Results: The proportions of preterm births were spontaneous 69% (with PROM 27% and with intact membranes 42%) and medically indicated births 31%. A risk factor associated with prematurity was identified in 98 and 85% of medically indicated and spontaneous births, respectively. Ascending bacterial infection (ABI) was the most frequently associated factor with spontaneous preterm delivery in 51% of women (142/280, p < 0.01) and with preterm births of less than 30 weeks in 52% of women (82/157, p < 0.01). Vaginal or urinary infection with Group B Streptococcus, was the most common clinical condition associated with ABI related deliveries. Hypertension was present in 94 of 127 medically indicated preterm deliveries (preeclampsia in 62% and chronic hypertension in 12%), and in 29% (preeclampsia 24%) of preterm births of more than 30 weeks. Congenital anomalies were mainly associated with a maternal age over 35 years in 15% (14/92) of women. The frequency of placental diseases was higher in spontaneous preterm deliveries (14%) and in pregnancies of more than 30 weeks in (14%). Conclusions: ABI was the most common factor associated with spontaneous preterm births at 2234 weeks, while preeclampsia is the most common factor associated with medically indicated preterm births.

Maternal cardiac output between 11 and 13 weeks of gestation in the prediction of preeclampsia and small for gestational age.

OBJECTIVE: To investigate maternal cardiac output in the first trimester as a predictor of preeclampsia and delivery of small for gestational age (SGA) infants. METHODS: In women attending for routine care between 11(+0) and 13(+6) weeks of gestation, we recorded maternal variables and measured cardiac output by echocardiography. We compared cardiac output in those that developed preeclampsia (n=83), pregnancy-induced hypertension (PIH) (n=87), or SGA (n=532) with those unaffected by preeclampsia, PIH, or SGA (n=3,591). Regression analysis was used to first determine which of the factors among the maternal variables were significant predictors of cardiac output in the unaffected group and, secondly, to predict each complication by a combination of maternal variables and cardiac output. RESULTS: In the unaffected group, cardiac output increased with gestation and maternal weight and decreased with maternal age. Cardiac output was higher in parous women, in cigarette smokers, in those taking antihypertensive or beta-mimetic medications, and in those conceiving after in vitro fertilization, and lower in women of Afro-Caribbean origin. Compared with the unaffected group, cardiac output was significantly higher in the preeclampsia and PIH groups and lower in the SGA group. In screening by cardiac output and maternal variables, for a 10% false-positive rate, the detection rates were 43.4% for all preeclampsia, 52% for preeclampsia without SGA, 23.3% for PIH, and 23.9% for SGA. CONCLUSION: In pregnancies complicated by preeclampsia, PIH, and SGA, alterations in maternal cardiac output predate the clinical onset of the disorders by several months. Maternal cardiac output in the first trimester is increased in women who develop preeclampsia and decreased in women who deliver SGA infants. LEVEL OF EVIDENCE: II.

Pseudocoartación de la aorta / Pseudocoarctation of the aorta

La pseudocoartación de la aorta es una elongación tortuosa del cayado aórtico con acodadura en la inserción del ligamento arterioso, sin reducción importante de su lumen, gradientes significativos de presión ni desarrollo de circulación colateral. Entre 12 pacientes estudiados desde 1975 habían 10 varones, el promedio de edad fue 15,6 años, habían cardiopatías asociadas en 9: en 5, estenosis valvulares aórticas; en 2, válvulas aortas bicúspides con insuficiencia aórtica; un caso de comunicación interauricular, tipo ostium secundum y uno de comunicación interventricular. Siete pacientes fueron referidos para estudiar la cardiopatía asociada, 5 por densidades radiológicas paramedianísticas. Sólo en un caso había hipertensión arterial que era de origen renovascular. Los pulsos femorales eran normales en 9 pacientes y ligeramente disminuidos en otros tres que tenían estenosis aórtica. La pseudocoartación fue confirmada mediante estudio hemodinámico, no había gradiente de presión en 4 pacientes, en otros 6 no eran significativas (2 a 17 mmHg), y en dos pacientes hizo el registro. La aortografía biplana y la cineaortografía en 2 planos demostraron las alteraciones morfológicas características en la aorta

Incidencia de cardiopatías congénitas en nacidos vivos / Incidence of congenital heart diseases in live born infants

De un total de 7.370 nacidos vivos durante 1983 en un hospital metropolitano de Santiago, 730 fueron referidos para estudio en la Unidad de Cardiología pediátrica, encontrando 101 pacientes con cardiopatías congénitas, lo que representa una incidencia de 13,70 por mil nacidos vivos. La mayoría de ellas (74%) fueron pesquisadas durante el primer mes de vida, el resto, en edades mayores, a lo largo de un período de seguimiento de 20 a 32 semanas. La presencia de soplos anorgánicos se detectó en 68 de 730 niños referidos a cardiología, desapareciendo en 30 de ellos (45%) en los controles sucesivos. De los 22 síndromes genéticos detectados en la población estudiada, 14 correspondieron a síndrome de Down y 11 de ellos (79%) tenían cardiopatías congénitas. Se encontraron malformaciones asociadas en 15 de los 101 (14,8%) pacientes con cardiopatías congénitas. Durante el primer año de vida, fallecieron 17 de los 101 pacientes: letalidad 168 por mil. La tasa descrita para cardiopatías congénitas en este estudio es la primera que se comunica en nuestro medio, y es mayor que la descrita en el extranjero. La distribución porcentual relativa concuerda en general con la descrita por otros autores