Definición de la presión arterial normal a las 11-14 semanas de gestación según riesgo / Definition of normal blood pressure at 11 to 14 weeks' gestation according to risk

Resumen Objetivo: Definir la presión arterial normal en el primer trimestre de la gestación según el desempeño para predecir preeclampsia. Método: Estudio de cohorte en embarazos de feto único, según el modelo de riesgos en competencia para preeclampsia. La presión arterial se midió de manera estandarizada entre las 11 y 14 semanas de gestación. Resultados: En 797 embarazos incluidos hubo 40 (5.0%, intervalo de confianza del 95% [IC 95%]: 3.6-6.4) partos con preeclampsia. Las presiones arteriales sistólica, diastólica y media fueron respectivamente de 101 (9), 68 (8) y 79 (8) mmHg en las embarazadas que no desarrollaron preeclampsia, frente a 109 (10), 75 (8) y 86 (8) mmHg en las que sí (p < 0.001, prueba t de Student). Las áreas bajo la curva fueron 0.707 (0.637-0.777), 0.728 (0.661-0.795) y 0.738 (0.673-0.803). A 3% de falsos positivos, los puntos de corte fueron 119, 83 y 94 mmHg con valores predictivos negativos del 95.6%. Conclusiones: Es factible definir normalidad para la presión arterial en el embarazo con base bioestadística y clínica.

Abstract Objective: To define normal blood pressure at first trimester of pregnancy by performance for pre-eclampsia prediction. Method: A cohort study in singleton pregnancies, according to the competing risks model for pre-eclampsia. Blood pressure was measured according to a standardized method at 11 to 14 weeks' gestation. Results: Among 797 pregnancies included, there were 40 (5.0%, IC95 3.6; 6.4) deliveries with pre-eclampsia. The systolic, diastolic, and mean arterial blood pressures were respectively of 101(9), 68(8) and 79(8) mmHg in pregnant women who did not develop pre-eclampsia, against 109(10), 75(8) and 86(8) in those who did (p < 0.001, t-test). The areas under the curves were 0.707 (0.637; 0.777), 0.728 (0.661; 0.795), and 0.738 (0.673; 0.803). At a 3% of false positive rate, the cut-off points were 119, 83 and 94 mmHg with predictive values of negative of 95.6%. Conclusions: It is feasible to define the normal values for blood pressure in pregnancy on biostatistic and clinical basis.

Definition of normal blood pressure at 11 to 14 weeks' gestation according to risk.

OBJECTIVE: To define normal blood pressure at first trimester of pregnancy by performance for pre-eclampsia prediction. METHOD: A cohort study in singleton pregnancies, according to the competing risks model for pre-eclampsia. Blood pressure was measured according to a standardized method at 11 to 14 weeks' gestation. RESULTS: Among 797 pregnancies included, there were 40 (5.0%, IC95 3.6; 6.4) deliveries with pre-eclampsia. The systolic, diastolic, and mean arterial blood pressures were respectively of 101(9), 68(8) and 79(8) mmHg in pregnant women who did not develop pre-eclampsia, against 109(10), 75(8) and 86(8) in those who did (p < 0.001, t-test). The areas under the curves were 0.707 (0.637; 0.777), 0.728 (0.661; 0.795), and 0.738 (0.673; 0.803). At a 3% of false positive rate, the cut-off points were 119, 83 and 94 mmHg with predictive values of negative of 95.6%. CONCLUSIONS: It is feasible to define the normal values for blood pressure in pregnancy on biostatistic and clinical basis.

OBJETIVO: Definir la presión arterial normal en el primer trimestre de la gestación según el desempeño para predecir preeclampsia. MÉTODO: Estudio de cohorte en embarazos de feto único, según el modelo de riesgos en competencia para preeclampsia. La presión arterial se midió de manera estandarizada entre las 11 y 14 semanas de gestación. RESULTADOS: En 797 embarazos incluidos hubo 40 (5.0%, intervalo de confianza del 95% [IC 95%]: 3.6-6.4) partos con preeclampsia. Las presiones arteriales sistólica, diastólica y media fueron respectivamente de 101 (9), 68 (8) y 79 (8) mmHg en las embarazadas que no desarrollaron preeclampsia, frente a 109 (10), 75 (8) y 86 (8) mmHg en las que sí (p < 0.001, prueba t de Student). Las áreas bajo la curva fueron 0.707 (0.637-0.777), 0.728 (0.661-0.795) y 0.738 (0.673-0.803). A 3% de falsos positivos, los puntos de corte fueron 119, 83 y 94 mmHg con valores predictivos negativos del 95.6%. CONCLUSIONES: Es factible definir normalidad para la presión arterial en el embarazo con base bioestadística y clínica.

Reference values for uterine artery mean pulsatility index throughout pregnancy customized by parity, transvaginal measurement and blood pressure.

INTRODUCTION: Population-specific reference ranges for uterine artery (UtA) mean pulsatility index (PI) throughout pregnancy have been shown to be of value in antenatal care. OBJECTIVE: To construct reference values for UtA mean PI throughout pregnancy, customized by maternal characteristics, transvaginal measurement and blood pressure in a Mexican population. METHODS: Cross-sectional study in 2286 normal singleton pregnancies in Mexico City. Blood pressure and UtA mean PI were measured using standardized methodology. Reference ranges by gestation were constructed. The effects of independent variables were tested by multiple linear regression. RESULTS: UtA mean PI median value between 11 and 41 weeks decreased from 1.714 to 0.523. The 95th percentile decreased from 2.600 to 0.653. Previous parity without preeclampsia had the main effect on UtA mean PI. Mean blood pressure had an effect on UtA mean PI by interaction with parity. Previous preeclampsia had an effect on UtA mean PI by interaction with maternal characteristics. A correction factor was obtained for transvaginal measurement. CONCLUSIONS: UtA mean PI usually decreases according to placentation and maternal adaptation to pregnancy. The effects of parity on blood pressure and UtA mean PI might reflect cardiovascular remodeling after gestation.

INTRODUCCIÓN: Los rangos de referencia de población específica para el índice de pulsatilidad medio de la arteria uterina (IPmAUt) durante el embarazo han demostrado valor en el cuidado prenatal. OBJETIVO: Construir valores de referencia para el IPmAUt durante el embarazo, personalizados por características maternas, medición transvaginal y presión arterial en una población mexicana. MÉTODOS: Estudio transversal de 2286 embarazos normales de feto único en la Ciudad de México. La presión arterial y el IPmAUt se midieron mediante metodología estandarizada. Se construyeron rangos de referencia por gestación. Los efectos de las variables independientes se probaron mediante regresión lineal múltiple. RESULTADOS: La mediana del IPmAUt entre las 11 y 41 semanas disminuyó de 1.714 a 0.523. El percentil 95 disminuyó de 2.600 a 0.653. La paridad sin preeclampsia previa representó el principal efecto sobre el IPmAUt. La presión arterial media tuvo efecto sobre el IPmAUt por interacción con la paridad. La preeclampsia previa tuvo efecto sobre el IPmAUt por interacción con las características maternas. Se obtuvo un factor de corrección para medición transvaginal. CONCLUSIONES: El IPmAUt disminuye normalmente según la placentación y adaptación materna al embarazo. Los efectos de la paridad sobre la presión arterial y el IPmAUt podrían reflejar remodelación cardiovascular posterior a la gestación.

Valores de referencia personalizados para el índice de pulsatilidad medio de la arteria uterina durante el embarazo según paridad, medición transvaginal y presión arterial / Reference values for uterine artery mean pulsatility index throughout pregnancy customized by parity, transvaginal measurement and blood pressure

Resumen Introducción: Los rangos de referencia de población específica para el índice de pulsatilidad medio de la arteria uterina (IPmAUt) durante el embarazo han demostrado valor en el cuidado prenatal. Objetivo: Construir valores de referencia para el IPmAUt durante el embarazo, personalizados por características maternas, medición transvaginal y presión arterial en una población mexicana. Métodos: Estudio transversal de 2286 embarazos normales de feto único en la Ciudad de México. La presión arterial y el IPmAUt se midieron mediante metodología estandarizada. Se construyeron rangos de referencia por gestación. Los efectos de las variables independientes se probaron mediante regresión lineal múltiple. Resultados: La mediana del IPmAUt entre las 11 y 41 semanas disminuyó de 1.714 a 0.523. El percentil 95 disminuyó de 2.600 a 0.653. La paridad sin preeclampsia previa representó el principal efecto sobre el IPmAUt. La presión arterial media tuvo efecto sobre el IPmAUt por interacción con la paridad. La preeclampsia previa tuvo efecto sobre el IPmAUt por interacción con las características maternas. Se obtuvo un factor de corrección para medición transvaginal. Conclusiones: El IPmAUt disminuye normalmente según la placentación y adaptación materna al embarazo. Los efectos de la paridad sobre la presión arterial y el IPmAUt podrían reflejar remodelación cardiovascular posterior a la gestación.

Abstract Introduction: Population-specific reference ranges for uterine artery (UtA) mean pulsatility index (PI) throughout pregnancy have been shown to be of value in antenatal care. Objective: To construct reference values for UtA mean PI throughout pregnancy, customized by maternal characteristics, transvaginal measurement and blood pressure in a Mexican population. Methods: Cross-sectional study in 2286 normal singleton pregnancies in Mexico City. Blood pressure and UtA mean PI were measured using standardized methodology. Reference ranges by gestation were constructed. The effects of independent variables were tested by multiple linear regression. Results: UtA mean PI median value between 11 and 41 weeks decreased from 1.714 to 0.523. The 95th percentile decreased from 2.600 to 0.653. Previous parity without preeclampsia had the main effect on UtA mean PI. Mean blood pressure had an effect on UtA mean PI by interaction with parity. Previous preeclampsia had an effect on UtA mean PI by interaction with maternal characteristics. A correction factor was obtained for transvaginal measurement. Conclusions: UtA mean PI usually decreases according to placentation and maternal adaptation to pregnancy. The effects of parity on blood pressure and UtA mean PI might reflect cardiovascular remodeling after gestation.

Presión arterial en embarazos normales de la Ciudad de México / Blood pressure in normal pregnancies from Mexico City

Resumen Objetivo: Determinar la presión arterial (PA) normal en embarazadas en la Ciudad de México. Método: Estudio transversal descriptivo de la PA en embarazos normales de feto único en la Ciudad de México. Las mediciones siguieron un método estandarizado con uso de dispositivos electrónicos automatizados. Se construyeron valores de referencia de las presiones sistólica (PS), diastólica (PD) y arterial media (PAM). Se probaron los efectos de las características maternas y de la gestación sobre la PA. Los intervalos de referencia de la PA se ajustaron para las variables significativas. Resultados: En 1,056 mujeres con edad media de 33 años y 160 cm medios de estatura se realizaron 1,915 mediciones entre las 5 y 41 semanas de edad gestacional (EG) con peso medio de 65 kg. La PA durante el embarazo fue de 102.7/67.2 ± 9.3/7.4 DE mmHg y 79.0 ± 7.4 DE mmHg la PAM. La PA tuvo una relación cuadrática con la EG, la más baja en el segundo trimestre. La PS y la PD mostraron una correlación lineal (r = 0.71). El peso materno tuvo el efecto más significativo sobre PS y PAM; la estatura sobre la PD. La edad, etnia, paridad, consumo de tabaco y antecedente familiar ejercieron efectos diferentes en cada PA. La gestación no tuvo efecto significativo en el modelo multivariado de la PS. Conclusiones: La PA se halló por debajo de la norma convencional en embarazadas. Los criterios diagnósticos para hipertensión en el embarazo deben revisarse; los valores de referencia pueden ajustarse a características maternas y gestacionales.

Abstract Objective: To determine the normal blood pressure (BP) in pregnancy, Mexico City. Methods: A cross-sectional observational study was carried out of BP on singleton normal pregnancies in Mexico City. Measurements followed a standardised methodology using automated electronic devices. Reference values of systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP) were constructed. Maternal and gestation characteristics effects on BP were tested. The reference ranges of BP were adjusted for significant variables. Results: On 1,056 women of 33 years old mean age and 160.0 cm mean height, 1,915 measurements were made between 5 and 41 weeks of gestational age (GA) with 65.0 kg of mean weight. The median BP throughout pregnancy was 102.7/67.2 ± 9.3/7.4 SD mmHg, and 79.0 ± 7.4 SD mmHg the MAP. BP had a quadratic relationship with GA, being the lowest in 2nd trimester. SBP and DBP had a r = 0.71 linear correlation. Maternal weight had the most significant effect on SBP and MAP; height, on DBP. Maternal age, ethnic origin, parity, tobacco habit and family history had differential effects on BP. Gestation had no significant effect on SBP multivariate model. Conclusions: BP resulted lower than conventional standard for pregnant women. Diagnostic criteria for hypertension in pregnancy must be revised; reference values can be adjusted by maternal and gestation characteristics.

Presión arterial en embarazos normales de la Ciudad de México.

OBJECTIVE: To determine the normal blood pressure (BP) in pregnancy, Mexico City. METHODS: A cross-sectional observational study was carried out of BP on singleton normal pregnancies in Mexico City. Measurements followed a standardised methodology using automated electronic devices. Reference values of systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP) were constructed. Maternal and gestation characteristics effects on BP were tested. The reference ranges of BP were adjusted for significant variables. RESULTS: On 1,056 women of 33 years old mean age and 160.0 cm mean height, 1,915 measurements were made between 5 and 41 weeks of gestational age (GA) with 65.0 kg of mean weight. The median BP throughout pregnancy was 102.7/67.2 ± 9.3/7.4 SD mmHg, and 79.0 ± 7.4 SD mmHg the MAP. BP had a quadratic relationship with GA, being the lowest in 2nd trimester. SBP and DBP had a r = 0.71 linear correlation. Maternal weight had the most significant effect on SBP and MAP; height, on DBP. Maternal age, ethnic origin, parity, tobacco habit and family history had differential effects on BP. Gestation had no significant effect on SBP multivariate model. CONCLUSIONS: BP resulted lower than conventional standard for pregnant women. Diagnostic criteria for hypertension in pregnancy must be revised; reference values can be adjusted by maternal and gestation characteristics.

OBJETIVO: Determinar la presión arterial (PA) normal en embarazadas en la Ciudad de México. MÉTODO: Estudio transversal descriptivo de la PA en embarazos normales de feto único en la Ciudad de México. Las mediciones siguieron un método estandarizado con uso de dispositivos electrónicos automatizados. Se construyeron valores de referencia de las presiones sistólica (PS), diastólica (PD) y arterial media (PAM). Se probaron los efectos de las características maternas y de la gestación sobre la PA. Los intervalos de referencia de la PA se ajustaron para las variables significativas. RESULTADOS: En 1,056 mujeres con edad media de 33 años y 160 cm medios de estatura se realizaron 1,915 mediciones entre las 5 y 41 semanas de edad gestacional (EG) con peso medio de 65 kg. La PA durante el embarazo fue de 102.7/67.2 ± 9.3/7.4 DE mmHg y 79.0 ± 7.4 DE mmHg la PAM. La PA tuvo una relación cuadrática con la EG, la más baja en el segundo trimestre. La PS y la PD mostraron una correlación lineal (r = 0.71). El peso materno tuvo el efecto más significativo sobre PS y PAM; la estatura sobre la PD. La edad, etnia, paridad, consumo de tabaco y antecedente familiar ejercieron efectos diferentes en cada PA. La gestación no tuvo efecto significativo en el modelo multivariado de la PS. CONCLUSIONES: La PA se halló por debajo de la norma convencional en embarazadas. Los criterios diagnósticos para hipertensión en el embarazo deben revisarse; los valores de referencia pueden ajustarse a características maternas y gestacionales.

Validation of a preeclampsia early screening test in a Mexican population.

BACKGROUND: No preeclampsia screening test has been validated in our country. OBJECTIVE: To assess the fit and performance of the FMF 4.0 Bayesian algorithm in a Mexican population. METHOD: Cohort study in singleton pregnancies, according to the competing risks model for preeclampsia. A priori risk was calculated based on medical history. Mean blood pressure (MBP), uterine artery mean pulsatility index (UtAmPI) and pregnancy-associated plasma protein A (PAPP-A) were measured at 11-14 weeks of gestation using standardized methodology. The value of each marker was transformed into multiples of the median (MoM) by the originala algorithm and by population-correctionb. Multivariate normal distribution and Bayes theorem were applied to obtain post-test probabilities. RESULTS: There was 5.0% (40/807) of preeclampsia. Distributions in women without preeclampsia were MBP = 0.927a vs. 0.991b, UtAmPI = 0.895a vs. 1.030b and PAPP-A = 0.815a vs. 0.963b (p < 0.001). The AUC was 0.821a vs. 0.823b. For a detection rate of 69 %, cutoff points were 1 in 240a and 1 in 120b, with false positive rates of 31 %a and 29 %b. CONCLUSIONS: The model has to be adjusted to the target population.

ANTECEDENTES: Ninguna prueba de tamiz de preeclampsia ha sido validada en nuestro país. OBJETIVO: Evaluar el ajuste y rendimiento del algoritmo bayesiano FMF 4.0 en una población mexicana. MÉTODO: Estudio de cohorte en embarazos de feto único, según el modelo de riesgos en competencia para preeclampsia. El riesgo a priori se calculó por historia clínica. La presión arterial media (PAM), el índice de pulsatilidad medio de la arteria uterina (IPmAUt) y la proteína plasmática A asociada al embarazo (PAPP-A) se midieron a las 11-14 semanas de gestación con metodología estandarizada. El valor de cada marcador se transformó en múltiplos de la mediana (MoM) por el algoritmo originala y el corregidob a la población. Se aplicaron la distribución normal multivariante y el teorema de Bayes para las probabilidades posprueba. RESULTADOS: Hubo un 5.0% (40/807) de preeclampsia. Las distribuciones sin preeclampsia fueron PAM 0.927a vs. 0.991b, UtAmPI 0.895a vs. 1.030b y PAPP-A 0.815a vs. 0.963b (p < 0.001). El área bajo la curva fue 0.821a vs. 0.823b. Para una detección del 69%, los puntos de corte fueron 1 en 240a y 1 en 120b, a falsos positivos del 31%a y 29%b. CONCLUSIONES: El modelo debe ajustarse a la población diana.

Validación de la calculadora de la Fundación de Medicina Fetal para tamiz de preeclampsia adaptada a población mexicana / Validation of the Fetal Medicine Foundation calculator for pre-eclampsia screening test adapted to a Mexican population

Resumen OBJETIVO: Validar el rendimiento de la calculadora de la Fundación de Medicina Fetal 4.0 adaptada a población mexicana. MATERIALES Y MÉTODOS: Estudio de cohorte efectuado en embarazos con feto único, según el modelo de riesgos en competencia para preeclampsia en un centro de medicina fetal de la Ciudad de México. El riesgo a priori se calculó de acuerdo con la historia clínica. La presión arterial media, el índice de pulsatilidad medio de la arteria uterina y la proteína plasmática A asociada al embarazo se midieron a las 11 a 14 semanas de gestación con metodología estandarizada. El valor de cada marcador se transformó en múltiplos de la mediana adaptados a la población local. Se aplicaron la distribución normal multivariante y el teorema de Bayes para obtener las probabilidades posprueba individuales, que se utilizaron como clasificadores para el área bajo la curva de característica receptor-operador. RESULTADOS: La incidencia de preeclampsia fue del 5.0% (54/1078). El área bajo la curva de característica receptor-operador fue de 0.784 (0.712; 0.856) para preeclampsia a menos de 37 semanas y de 0.807 (0.762; 0.852) para preeclampsia global. CONCLUSIONES: La calculadora FMF 4.0 adaptada a población mexicana resultó válida. Si bien tuvo menor rendimiento al esperado para preeclampsia a menos de 37 semanas, el rendimiento para preeclampsia global fue satisfactorio. Se justifica desarrollar la calculadora local.

Abstract OBJECTIVE: To validate the performance of the Fetal Medicine Foundation 4.0 calculator adapted to the Mexican population. MATERIALS AND METHODS: Cohort study performed in singleton pregnancies, according to the competing risk model for preeclampsia in a fetal medicine center in Mexico City. The a priori risk was calculated according to the clinical history. Mean arterial pressure, mean uterine artery pulsatility index and pregnancy-associated plasma protein A were measured at 11 to 14 weeks of gestation with standardized methodology. The value of each marker was transformed into multiples of the median adapted to the local population. Multivariate normal distribution and Bayes' theorem were applied to obtain individual posttest probabilities, which were used as classifiers for the area under the receiver-operator characteristic curve. RESULTS: The incidence of preeclampsia was 5.0% (54/1078). The area under the receiver-operator characteristic curve was 0.784 (0.712; 0.856) for preeclampsia at less than 37 weeks and 0.807 (0.762; 0.852) for global preeclampsia. CONCLUSIONS: The FMF 4.0 calculator adapted to Mexican population proved valid. Although it had lower performance than expected for preeclampsia at less than 37 weeks, the performance for global preeclampsia was satisfactory. The development of the local calculator is justified.

[Prenatal screening for anueploidies in the first trimester: Audit to a Fetal Medicine Centre with specialized Laboratory in Mexico]. / Tamiz prenatal de aneuploidías en el primer trimestre: auditoría a un centro de medicina fetal con laboratorio especializado en México.

BACKGROUND: Screening for aneuploidies using ultrasound and biochemical first trimester markers has an expected performance if the qualification requirements are fulfilled. OBJECTIVE: To describe the first trimester markers in Mexico through the audit to a Fetal Medicine Centre and Laboratory. MATERIAL AND METHOD: Descriptive study conducted with the audit method of ultrasound and biochemical markers in pregnancies that prenatal screening tests in the first quarter were made between 11 + 1 and 14 + 1 weeks pregnant patients who came to the Laboratorio del Centro Médico para Atención Fetal Especializada. RESULTS: In 17 months n=1020 pregnancies, 962 (94.3%) single, 55 (5.4%) doubles, and 3 (0.3%) triplets. Median maternal age of 33.8 years (16-52), 413 (40.5%) > or = 35 years. 1080 foetuses with 1009 valid measurements of nuchal translucency (29.8% at external cabinets), 54% >p50; 7.3% >p95, and 1.6% > p99. Out of 1555 sera processed at the Laboratory (f-beta-hCG and PAPP-A, Roche), 641 (41.2%) were interpreted at external centres. In 914 sera the f-beta-hCG MoM were p50 = 0.72, 3.2% >p95; for PAPP-A, p50 = 0.89, 9.0% < p5. There were 850 combined tests, and in 745 an additional marker was added; the IP ductus venosus median was 0.99 MoM. A risk > or =1 in 100 resulted in 50 foetuses (4.6%); 27 underwent invasive procedure at our Centre, 19 normal karyotypes, and 8 abnormal as: 3 trisomy 21 and 5 diverse aneuploidies. CONCLUSIONS: The qualification requirements are fulfilled for nuchal translucency, ductus venosus, and the combined test; 1 out of 3 invasive procedures resulted an aneuploidy; the estimated false positive rate is 3.9%. The Laboratory will adjust the median values of the biochemical markers. A cohort study has begun.

[Causes of preterm delivery among adolescent mothers]. / Causas de nacimiento pretérmino entre madres adolescentes.

OBJECTIVE: To describe the proportion of preterm delivery at pregnant adolescents clinic and their maternal, obstetric and fetal conditions other than spontaneous labor. PATIENTS AND METHOD: Descriptive inside a cohort of consecutive cases. Preterm was defined from 20 to 36 full weeks. Maternal, obstetric and fetal conditions were defined if directly caused preterm labor or elective interruption; it was differentiated from spontaneous preterm labor. RESULTS: Preterm delivery rate was 10.8% (252/2326): 0.8% from 20 to 27 weeks (19/2326), 3.3% from 28 to 33 weeks (77/2326) and 6.7% from 34 to 36 weeks (156/2326). Spontaneous preterm labor presented in 39.3% (99/252); main conditions found were: rupture of the membranes 18.7% (47/252), preeclampsia-eclampsia 10.3% (26/252), twin pregnancy 10.3% (26/252), intrauterine growth restriction 5.6% (14/252) and congenital defects 5.6% (14/252). They were classified as: obstetric-type 34.9% (887252), fetal 25.4% (64/252) and maternal 0.4% (1/252). There was a 40.5% rate of vaginal delivery (102/252), with the use of forceps in 1 out of 5. CONCLUSIONS: At purpose-built clinics using evidence-based and problem oriented interventions, that are individually adapted and continuously up-dated, a non-risk comparable preterm delivery rate can be achieved at gestational ages with better neonatal prognosis.

[Analysis of the perinatal results of the first five years of the functioning of a clinic for pregnant teenagers]. / Análisis de los resultados perinatales de los primeros cinco años del funcionamiento de una clínica de atención para adolescentes embarazadas.

OBJECTIVE: To evaluate the perinatal outcomes within a pregnant cohort of adolescents aged 16 years and younger. PATIENTS AND METHODS: Case review prospective study. All pregnant adolescents who attended to the Coordination for assistance of the adolescent patient from June 1998 to July 2003 were included. INCLUSION CRITERIA: age, irrespective from antenatal care inside or outside of the Coordination and delivering inside the institution. Variables analyzed were: age, occupation, marital status, gestational age at first antenatal visit, number of antenatal visits, medical complications during pregnancy, gestational age on delivery, mode of delivery and contraceptive acceptance on discharge. Neonatal variables: weight at birth and intensive care admissions. Statistical analysis included descriptive measures. RESULTS: We identified 2723 pregnant adolescents, from whom only 2,315 met the inclusion criteria. Mean maternal age was 15.3 (SD 0.87). From the total 58% were single and 83.4% were households while only. Mean gestational age on first visit at the coordination was 24.26 (SD 6.79) weeks. The average number of antenatal visits was 4.78 (SD 3.99). The most frequent medical complications affected the genital and urinary tract, with a 54.2% of cervical and vaginal infections, and a 23.8% of urinary tract infections; anemia in 16.7%, threatened preterm delivery in 9.2% and pregnancy induced hypertension in 3.8%. From the total of cases the 79.1% presented with any morbidity. Mean gestational age concluded at 37.58 (SD 3.03), the preterm delivery rate was 15.4%. The most frequent way of delivery was vaginal with a 55.8% rate. On the neonatal outcomes, the mean birth weight was 2819.07 (SD 613.85). The contraceptive acceptance on the discharge was 98%. CONCLUSIONS: The adolescent pregnant has a high risk of suffering major complications, such as genital and urinary tract infections, anemia and preterm delivery.

[Quantification of perinatal risk in Mexican adolescents: consequences of maternal low weight]. / Cuantificación del riesgo perinatal en adolescentes mexicanas: consecuencias del bajo peso materno.

OBJECTIVE: To determine whether a pregnant adolescent whose weight-for-age is less than 90% is on the risk of delivering a baby who is small for gestational age. PATIENTS AND METHOD: Six hundred and one adolescents aged 12-16 years, at 40 weeks of gestation were included. Body weight was measured at baseline with Mexican reference tables. Low maternal weight was considered less than 90%. Rate of small for gestational age at birth was determined for each group. Comparisons were made using chi2 and relative risks were estimated. RESULTS: The rate of small for gestational age among adolescents with low body weight was 16.1% (30/186), it differed significantly (36/415) from the others (8.7%). Relative risk for small for gestational age babies among adolescents with low body weight was 1.9 (95% CI, 1.2 - 2.9). An exploratory analysis suggests that this effect depends on gestational age. CONCLUSIONS: If body weight of a pregnant adolescent is to be evaluated in the absence of a previous record, tables by Arroyo can be used as reference; if body weight is less than 90%, then you have an indicator of perinatal risk.

[Perinatal implications of pregnancy in adolescent women]. / Implicaciones perinatales del embarazo en la mujer adolescente.

OBJECTIVE: To establish if there are differences on obstetric and perinatal outcomes between adolescents who are younger than 16 with young adults aging 20 to 24 years old. PATIENTS AND METHOD: A double-cohort prospective and comparative study in 328 Mexican pregnant women. Cohort I included 153 pregnant adolescents younger than 16 years old and cohort II included 175 young adults aging 20 to 24 years old. Inclusion criteria for both groups were: healthy, singleton, primigravidas, with 4 or more antenatal care visits and delivery at institution. STATISTICAL ANALYSIS: descriptive, t-test, chi-squared and Fisher's exact test. RESULTS: Cohort I: Mean age, 15 years old. Mean gestational age on first visit, 22.35 +/- 6.75 weeks. Morbidity was due mainly by vaginitis and vaginosis (p = 0.0001), urinary tract infection (p = 0.110) and anemia (p = 0.0001). Maternal weight on first visit was 54.11 +/- 9.11 (p = 0.001). In cohort II mean maternal age was 22 years old with a mean gestational age on first visit of 19.58 +/- 7.94 weeks. Main morbidity was: urinary tract infections, vaginitis-vaginosis and preeclampsia (p = 0.191). Mean maternal weight on first visit was 60.37 +/- 9.99. Gestational age on delivery and birth weight were not statistically different between newborns in each group. CONCLUSIONS: Pregnancy in adolescents should be considered of risk; nevertheless, adequacy in antenatal care provides good obstetric and perinatal outcomes.