Obstetrician-gynecologists as primary care physicians: the perspectives of health maintenance organization medical directors and obstetrician-gynecologists.

OBJECTIVE: To survey the interest of obstetrician-gynecologists in serving as primary care physicians and their perceived preparedness for that role from the view points of managed care plans and obstetrician-gynecologists. METHODS: A sample of obstetrician-gynecologists was asked to describe their preferred physician roles in managed care plans. Managed care medical directors were asked to define the obstetrician-gynecologist's role in their health plans. The mailed survey questions focused on 1) obstetrician-gynecologists' interest in serving as primary care physicians and/or gatekeepers, 2) direct access to obstetrician-gynecologists, and 3) additional training needed to serve as primary care physicians. RESULTS: Thirty-seven percent of obstetrician-gynecologists expressed little or no interest in serving as primary care physicians, and 37% had some or high interest. Fifty-six percent were not interested in serving as gatekeepers, and 45% believed that physicians in the specialty should not do so. Almost all believed women should be allowed direct access to obstetrician-gynecologists. Over half of the managed care plans allowed women to refer themselves to obstetrician-gynecologists, and one-third allowed these physicians to serve as primary care gatekeepers. Most plans believed that extensive additional training is needed for obstetrician-gynecologists to serve as gatekeepers, whereas 70% of specialists believed that little or no additional training is needed. CONCLUSION: Obstetrician-gynecologists do not all agree on their appropriate and preferred role as physicians in the managed care environment; 37% see themselves as primary care physicians, whereas 37% would rather act as consultative specialists. Nearly all, however, support direct access to obstetrician-gynecologists. Most (69.7%) believe that they are capable of serving as primary care gatekeepers with little or no additional training, but managed care plans believe otherwise.

Prostaglandin F2alpha binding sites in human corpora lutea.

The specific binding of 3H-prostaglandin (PG) F2alpha to homogenates of human corpora lutea of the cycle and ectopic pregnancy was examined. Corpora lutea of ectopic pregnancy bound significantly (P less than 0.01) higher amounts of added 3H-PGF2alpha than those of the luteal phase of the menstrual cycle. The 3H-PGF2alpha binding sites in corpora lutea of ectopic pregnancy were further characterized. The specific 3H-PGF2alpha binding to all corpora lutea was biphasic: all contained sites of 10(-8)M Kd, two also had sites of Kd greater than 10(-8)M while the other contained sites of 10(-9)M Kd. PGs competed for 3H-PGF2alpha binding in the following order: PGF2alpha greater than 15(S)15 methyl PGF2alpha greater than PGF1alpha greater than PGE2 greater than PGE1 greater than PGB1 greater than PGA1. Binding was time and temperature dependent; maximum binding was obtained by 1 h at 22 C; AT 38 C, the initial binding was high but rapidly declined after 30 min of incubation. A cationic requirement for 3H-PGF2ALPHA binding is suggested by the findings that the addition of EDTA severely reduced the binding which was reversed by concomittant addition of Ca+ to the medium. Preincubation of homogenates with proteolytic enzymes drastically reduced the binding, suggesting that the binding sites are protein in nature.

Gonadotropin receptors in human corpora lutea of the menstrual cycle and pregnancy.

Binding of 125I-human choriogonadotropin (hCG) to homogenates of corpora lutea of the menstrual cycle and pregnancy was examined. While corpora lutea of the menstrual cycle bound 125I-hCG, most of the corpora lutea of pregnancy from six to 34 weeks' gestation bound little or none of the added 125 I-hCG. Further exploration into various possibilities for the above findings led to the conclusion that these corpora lutea either contain very few gonadotropin receptors or lack them altogether. The selected properties of gonadotropin receptors in corpora lutea of the cycle were studied. The apparent dissociation constant for binding was about the same (2.6 to 3.8 x 10-10M) in all but one corpus luteum. In this one sample the constant was three- to five-fold higher (1.3 x 10-9M). The binding was quite rapid and reversible, and it exhibited dependence on the amount of 125I-hCG, homogenate protein, pH of the incubation media, and duration of incubation. hCG and human lutropin (hLH') competed for 125I-hCG binding, but hCG subunits (alpha and beta), human follitropin, and ovine prolactin did not. Although hCG and hLH were parallel in inhibiting 125I-hCG binding, hLH was found to be relatively less effective. The studies with various enzymes revealed that gonadotropin receptors are protein in nature.

Diagnostic ultrasound for detection of intrauterine growth retardation.

There were 738 fetal BPD determined in 468 normal obstetric patients between 16 and 43 weeks in whom (1) the size of the uterus on initial examination corresponded to the duration of amenorrhea +/- 1 week and (2) there were no complications during the pregnancy. The mean BPD +/- 2 S.D. was determined for each week. The rate of BPD growth was found to be 0.26 cm. per week from 18 to 38 weeks. One hundred random high-risk obstetric patients in whom the size of the uterus on initial examination corresponded to the weeks of amenorrhea +/- 1 week were studied. Two patterns of suspected IUGR are observed: one shows BPD values more than 2 S.D. below the mean; the other manifests a decreased delta BPD. Combinations of the two may be seen. At delivery seven neonates were identified who were SGA and could not be detected in utero by single BPD measurements.