The proportion of pregnancies that ended in induced abortion ranged from about 10% (Israel, the Netherlands and Switzerland) to 30% (Estonia) in the same group, though it might be as high as 36% in Hungary and Romania, whose statistics were deemed incomplete.An American study in 2002 concluded that about half of women having abortions were using a form of contraception at the time of becoming pregnant. Inconsistent use was reported by half of those using condoms and three-quarters of those using the birth control pill; 42% of those using condoms reported failure through slipping or breakage. The Guttmacher Institute estimated that "most abortions in the United States are obtained by minority women" because minority women "have much higher rates of unintended pregnancy". In a 2022 analysis by the Kaiser Family Foundation, while people of color comprise 44% of the population in Mississippi, 59% of the population in Texas, 42% of the population in Louisiana (by the state Health Department), and 35% of the population in Alabama, they comprise 80%, 74%, 72%, and 70% of those receiving abortions.The abortion rate may also be expressed as the average number of abortions a woman has during her reproductive years; this is referred to as total abortion rate (TAR). Gestational age and method
Abortion rates also vary depending on the stage of pregnancy and the method practiced.
Central nervous system imaging
Central nervous system abnormalities, such as cortical or subependymal tubers and astrocytomas, are common in patients with TSC, including those with TSC-LAM, but are not found in women with S-LAM. Moss and associates reported that women with S-LAM and TSC-LAM may have an increased incidence of meningioma, but the significance of that finding has been challenged. Pulmonary function studies
Pulmonary function testing in patients with LAM may be normal or may reveal obstructive, restrictive or mixed patterns. Obstructive physiology is the most common abnormality. Quality-controlled lung function data were collected prospectively by the NHLBI Registry, a 5-year study of patients with LAM in centers around the United States. Spirometry revealed obstructive changes in about 57% of patients and normal results in 34%. Restriction, defined as a total lung capacity less than the lower limit of normal, was seen in 11%. Hyperinflation was present in about 6%. The average residual volume was 125% of predicted when measured by plethysmography, but was only 103% of predicted determined with gas dilution methods, suggesting significant air trapping in noncommunicating airspaces. Approximately 25% of patients with obstructive physiology may demonstrate bronchodilator responsiveness but may be less in more severe obstruction. The obstructive physiologic defect in LAM is primarily attributable to airflow obstruction. The earliest change in initial pulmonary function testing in various case series was abnormal gas transfer, as assessed by the diffusing capacity for carbon monoxide (DLCO), described in 82% to 97% of patients.