[Classification of the characteristics of cesarean section at the Mexican Ministry of Health during the period of 1990-95]. / Comportamiento de la cesárea en la SSA durante el período 1990-95.

This is an analysis of the characteristics of cesarean section operations within the Ministry of Health (SSA) and the implications in relation to maternal and perinatal mortality during the five year period from 1990 to 1995. A descriptive study was undertaken based on cesarean section information obtained from the Statewide (Reporting) System of Basic Information (SEIR) and based on maternal and perinatal mortality information provided by the Ministry's Internal Hospital Committees from 1990 to 1995. This information was analyzed as a chronological series in order to compare the changes in the annual cesarean rates at both national and statewide levels. The Pearson test was used to determine the correlation between the frequency of cesarean sections and maternal and perinatal mortality rates during the same period within a 95 percent confidence interval (p < 0.05). The frequency of cesarean sections was shown to have increased within the SSA hospital system as whole and when considering each state separately. A positive and statistically significant correlation was observed between the frequency of cesarean sections and maternal mortality rates, while the increase in cesarean rates demonstrated no relationship with perinatal mortality rates. The increase in cesarean section rates in the Ministry of Health during the period analyzed exceeded any potential benefits and could have contributed to the increase in maternal morbidity and morbility as well as hospital cost. This increase is worrisome due to the projected tendency for the rates to continue to increase in the next few years if quick and concrete actions are not taken in order to decrease these rates.

Assessment of luteal function after surgical tubal sterilization.

To evaluate ovarian luteal function after tubal occlusion, a group of women who underwent Pomeroy sterilization were studied. A prospective group I (n = 16) were followed for one year and scheduled for blood sampling every other day during their luteal phase before surgical procedure and at 3 and 12 months thereafter. Group II (n = 15) included women who were studied during their luteal phase at 1 or 5 years post-surgery. Mid-luteal progesterone and estradiol serum levels were calculated by estimating the average of at least 3 values of serum samples obtained in days 20-25 of a menstrual cycle. The data suggest that no major changes occur in ovarian function after surgical tubal occlusion, as assessed by the mid-luteal hormone serum levels, and underscore the safety of this procedure.

[Long acting hormonal contraception]. / Anticoncepción hormonal de acción prolongada.

Long-acting hormonal contraception has been widely accepted in different cultures, where the use of injectables and implants is preferred over other methods of fertility control. The administration of synthetic progestogens in combination with estrogens as injectables suppresses ovulation, allowing the control of the endometrial bleeding too. The use of injectables containing only progesterone constitutes a 2 to 6 months contraceptive method with high effectiveness and easy administration, although its major disadvantage is the alteration of the endometrial bleeding pattern, which is the most common cause of discontinuation. The group of long-acting injectables includes the development of microencapsulated steroids, whose structure gives them the property of maintaining controlled liberation of the drug. Recently subdermal contraceptive implants (Norplant) have appeared, based on the subcutaneous sustained liberation of levonorgestrel. The daily drug dose is enough to inhibit ovulation in the initial months of use and modifies the cervical mucus in the subsequent months. Norplant has been shown to be efficient in preventing pregnancy, but main secondary effect is bleeding pattern disturbance during the menstrual cycle. The Capronor constitutes a new system of contraceptive implant which is different from Norplant, where the capsules containing levonorgestrel are of unbiodegradable material, and Capronor is formed by a biodegradable polimerus. Finally, among the contraceptive methods that have been developed to date there are the vaginal rings; these rings are silastic made and allow a continuous release of levonorgestrel or progestins.