Frozen-thawed embryo transfer: the potential importance of the corpus luteum in preventing obstetrical complications.

The use of frozen-thawed embryo transfer (FET) has increased over the past decade with improvements in technology and increasing live birth rates. FET facilitates elective single-embryo transfer, reduces ovarian hyperstimulation syndrome, optimizes endometrial receptivity, allows time for preimplantation genetics testing, and facilitates fertility preservation. FET cycles have been associated, however, with an increased risk of hypertensive disorders of pregnancy for reasons that are not clear. Recent evidence suggests that absence of the corpus luteum (CL) could be at least partly responsible for this increased risk. In a recent prospective cohort study, programmed FET cycles (no CL) were associated with higher rates of preeclampsia and preeclampsia with severe features compared with modified natural FET cycles. FET cycles are commonly performed in the context of a programmed cycle in which the endometrium is prepared with the use of exogenous E2 and P. In these cycles, ovulation is suppressed and therefore the CL is absent. The CL produces not only E2 and P, but also vasoactive products, such as relaxin and vascular endothelial growth factor, which are not replaced in a programmed FET cycle and which are hypothesized to be important for initial placentation. Emerging evidence has also revealed other adverse obstetrical and perinatal outcomes, including postpartum hemorrhage, macrosomia, and post-term birth specifically in programmed FET cycles compared with natural FET cycles. Despite the widespread use of FET, the optimal protocol with respect to live birth rate, maternal health, and perinatal outcomes has yet to be determined. Future practice regarding FET should be based on high-quality evidence, including rigorous controlled trials.

Cesación de tabaquismo en embarazo / Smoking cessation in pregnancy

Resumen En Chile, las mujeres en edad fértil y las embarazadas presentan una alta prevalencia de tabaquismo. El consumo de tabaco durante el embarazo tiene efectos prenatales (por ejemplo, aborto espontáneo, mortinatalidad) y es un factor de riesgo de morbilidad y mortalidad infantil. Todas las mujeres en edad fértil deben ser alentadas a dejar de fumar, y las mujeres que ya están embarazadas deben ser alentadas a dejar de fumar continuamente durante todo el embarazo, desde el momento más precoz posible hasta el período posterior al parto. Se presenta un conjunto de antecedentes y recomendaciones para la cesación de tabaquismo en embarazadas, basadas en guías internacionales sobre este tema.

In Chile, women of childbearing age and pregnant women have a high prevalence of smoking. Tobacco use during pregnancy has antenatal effects (spontaneous abortion, stillbirth) and it is a risk factor for infant morbidity and mortality. All women of childbearing age should be encouraged to quit smoking, and women who are already pregnant should be encouraged to stop smoking continuously throughout the pregnancy, from the earliest possible moment to the postpartum period. We present a set of background information and recommendations for smoking cessation in pregnant women, based on international guidelines on this topic.

An update on the risk factors for and management of obstetric haemorrhage.

Obstetric haemorrhage is associated with increased risk of serious maternal morbidity and mortality. Postpartum haemorrhage is the commonest form of obstetric haemorrhage, and worldwide, a woman dies due to massive postpartum haemorrhage approximately every 4 min. In addition, many experience serious morbidity such as multi-organ failure, complications of multiple blood transfusions, peripartum hysterectomy and unintended damage to pelvic organs, loss of fertility and psychological sequelae, including posttraumatic stress disorders. Anticipation of massive postpartum haemorrhage, prompt recognition of the cause and institution of timely and appropriate measures to control bleeding and replacement of the lost blood volume and restoration of oxygen carrying capacity (i.e. haemoglobin) and correction of the 'washout phenomenon' leading to coagulopathy will help save lives. Obstetric shock index may help in avoidance of underestimation of blood loss and the use of tranexamic acid, oxytocics and timely peripartum hysterectomy, if appropriate, will help save lives. Triple P procedure has been recently developed as the conservative surgical alternative for women with abnormal invasion of the placenta and has been shown to significantly reduce the blood loss and to reduce inpatient stay.

Smoking cessation in pregnancy.

More than 400,000 deaths occur per year in the United States that are attributable to cigarette smoking; the risks to the general public are widely known. The risk to women, especially those who are pregnant, is less commonly known. During pregnancy, smoking increases the risk of low birth weight infants, placental problems (previa and/or abruption), chronic hypertensive disorders, and fetal death. It is proposed that much of this happens because of vasoconstriction with decreased uterine blood flow from nicotine, carbon monoxide toxicity, and increased cyanide production. Infants of smoking mothers have increased risks, such as sudden infant death syndrome.

Uterine artery suture: a preventive approach for pernicious placenta previa.

Pernicious placenta previa is an obstetric complication that results in a crisis situation for many patients. Most existing options deal with the problems after delivery leading to unfavorable outcomes. To circumvent this situation, a few preventive simple surgical options have been discussed in this paper. The highlight of the approach is the application of ascending uterine artery suture that drastically reduced the amount of bleeding as compared to that observed in regular surgeries. Combined with the placenta accrete location, wedge resection and 'patch' homeostasis of the serous membrane, the surgical modifications adopted effectively reduced the need for hysterectomy thus preserving the fertility of the patients for the future. Since fetuses were safely removed within 1-2 min, the Apgar scores of the neonates were also largely unaffected.

Predicting placental abruption and previa in women with a previous cesarean delivery.

The purpose of this study was to determine if placental abruption or previa in women with a history of a prior cesarean delivery (CD) can be predicted. A retrospective cohort study of pregnant women with previous CD was conducted in 17 centers between 1996 and 2000. Women developing placenta previa or abruption in the subsequent pregnancy were compared with those without these complications. Bivariate and multivariable techniques were used to develop predictive models for placenta previa or abruption. The area under the receiver-operator characteristic curves, sensitivity, specificity, and accuracy of the models were compared. Among 25,076 women with prior CD, there were 361 (15 per 1000 births) with placenta previa and 309 (13 per 1000 births) with abruption. The significant risk factors for these complications include advanced maternal age, Asian race, increased parity, illicit drug use, history of spontaneous abortion, and three or more prior cesarean deliveries. Prediction models for abruption and previa had poor sensitivity (12% and 13% for abruption and previa, respectively). In women with at least one prior cesarean delivery, the risk factors for placental previa and abruption can be identified. However, prediction models combining these risk factors were too inefficient to be useful.

Síndrome de Munchausen y gestación / Syndrome of Munchausen and pregnancy

Las metrorragias en el tercer trimestre de la gestación que parecen un cuadro de placenta previa pueden corresponder a una llamada de atención del paciente hacia el médico. Esta situación clínica nace de alteraciones facticias que permiten al paciente adoptar el papel de enfermo. Ello puede conducir a una intervención quirúrgica inútil: cesárea por metrorragias, por ejemplo. La principal dificultad de la situación es diagnóstica. El tratamiento está basado en la psicoterapia, dirigida a mejorar la relación ulterior madre-hijo y puede prevenir actos de automutilación (AU)

Metrorrhagia during the third trimester of pregnancy, simulating placenta previa, may be a sign of the patient calling for help to the doctor. This clinical situation is one where the woman mimics an illness, in order to play the role of sick patient. The risk is that this may lead to unnecessary surgical procedures, in this case caesarean section. The main difficulty in caring for these patients is to make the diagnosis. Treatment is based on psychotherapy, which can contribute to an improved mother-infant relationship and perhaps prevent acts of self-mutilation (AU)