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Biomedical subjects

L Keith

Publications and source records attributed to L Keith.

At least 37 records · Page 2Linked to original sources
PubMed1990

Monthly cosmic activity and pregnancy induced hypertension.

Monthly distribution of PIH (Pregnancy Induced Hypertension) was investigated in relation to the number of deliveries and nine specific cosmic and geomagnetic activity parameters during the years 1979-1983. PIH was observed in 3.165% of 19,843 deliveries. Significant (p less than 0.01) inverse correlation between the PIH index and monthly geomagnetic activity level was shown. Moderately significant (p less than 0.05) correlation with monthly maximal (noon hours) gamma-radiowave propagation was evident as was inverse correlation with this parameter in hours of minimal (early morning) propagation.

Birth Rate↗
PubMed1990

Prevalence of marijuana use during pregnancy. A pilot study.

We examined the prevalence of marijuana use in a group of pregnant women using a qualitative, rapid urine screen to detect marijuana metabolites. Between July 1, 1987, and Aug 15, 1987, 322 consecutive patients underwent an anonymous urine toxicology screen at the time of admission to the labor-and-delivery unit. Patients were identified only by a consecutive number and by their age, race, marital status, gravidity, parity and obstetric service (clinic vs. private). The prevalence of positive urine toxicologic screens for marijuana was 19.9% among the study population (64 positive tests among 322 women screened). The prevalence was greater among the clinic patients than the private patients (52 of 161, or 32.3%, vs. 12 of 161, or 7.5%, respectively). The distribution of race and marital status among the marijuana-positive and -negative groups were also significantly different. Specifically, the proportions of black and single women were higher among the marijuana-positive group. Our findings suggest that marijuana use is common in our obstetric patients. The possible association between marijuana use during pregnancy and perinatal morbidity, as well as the unreliable nature of patient drug histories, may support the use of rapid, inexpensive screening techniques, especially if general screening is considered.

Adult↗
PubMed1988

Ultrasonic growth parameters in fetuses of mothers with primary addiction to cocaine.

Sixty-seven women with primary addiction to cocaine were evaluated during their pregnancies by multiple ultrasound studies. Ultrasonic parameters included biparietal diameter, femur length, abdominal circumference, and head circumference. These values were compared with ultrasonic growth parameters in nonaddicted fetuses. Head and abdominal circumference data were used to evaluate the fetuses according to growth pattern. With this system of scoring, subtleties of asymmetric versus symmetric intrauterine growth retardation become apparent. In addition, birth weights of addicted infants were compared with birth weights of nonaddicted infants. The results suggest that, although statistically significant differences in birth weights cannot be demonstrated, abnormal growth of the addicted fetuses does occur. Addicted fetuses show a greater proportion of biparietal diameter and abdominal circumference values below the 50th and 25th percentiles than nonaddicted fetuses, and addicted fetuses more frequently exhibit intrauterine growth retardation patterns. These data suggest that it is fruitful to study these infants with near-normal size but with abnormal intrauterine growth patterns.

Birth Weight↗
PubMed1985

Surface changes in intrauterine contraceptive devices after variable use.

Four used intrauterine contraceptive devices and two new control devices were studied by scanning electron microscopy. All intrauterine contraceptive devices were found to have surface deposits that differed not only from site to site on a given device but between devices. A finding of this study not previously described in the literature was the observation of a euhedral crystal rosette of an apatite mineral group [Ca5(PO4)3(F,Cl,OH)] on the Lippes Loop that had been in situ for 15 years.

Female↗
PubMed1984

The Northwestern University multihospital twin study. IV. Duration of gestation according to fetal sex.

Recently MacGillivray has observed that the average duration of male twin gestations is shorter than that of either female twin or male/female twin gestations. The data from 562 twin gestations from the Northwestern University multihospital twin study were used to test this observation. Male twin gestations were slightly but significantly shorter than other twin gestations as measured by pediatric examination (p less than 0.005). Approaching significance at the 0.05 level were findings that male twin gestations were shorter than other twin gestations when measured by dates, and that the male twins were slightly shorter and lighter than other twins. No significant differences were found between male/female twin gestations and female twin gestations. No relationship could be found between twin sex combinations and a variety of maternal and obstetric factors. Taken together, the results suggest that male twin gestations differ in some distinctive biologic sense from other twin gestations.

Adult↗
PubMed1984

Clinical experience with the prevention of Rh-isoimmunization: a historical comparative analysis.

Clinical experience with prevention of Rh-immunization is reviewed. The pathogenesis of hemolytic disease and the chemistry of prophylaxis is explained. The factors which effect antigenic expression are delineated. The clinical indications for prevention of AMIS are reviewed. International data pertaining to Rhesonativ are presented from postpartum trials and antepartum trials. A protocol for antepartum administration of anti-Rh immunoglobulin is given.

Epitopes↗
PubMed1982

The Northwestern University Drug Dependence Program: the impact of intensive prenatal care on labor and delivery outcomes.

In 1976, the Department of Obstetrics and Gynecology at the Prentice Women's Hospital was invited to provide obstetric services to patients of the Drug Dependence Program administered by the Department of Psychiatry at Northwestern University Medical School. Patients were referred in the early stages of pregnancy if they agreed to participate in the Drug Dependence Program at the same time. Between April, 1976, and October, 1980, 58 women received prenatal, intrapartum and postpartum care. Forty-two of these patients had been abusers of opiates; 16 were polydrug abusers. The obstetric performance of these women was characterized by an absence of major problems. The mean weight of all infants delivered was 2,935 gm. There were no perinatal deaths. The individual weights, lengths, and head circumferences of the newborn infants were distributed in a relatively normal manner. Ninety percent of the infants were delivered at 37 weeks or more of gestation.

Adult↗
PubMed1982

The vanishing twin.

In general, it has not been recognized that many twin or multiple gestations are lost in utero early in pregnancy. Until the advent of ultrasound, the ability to document early human fetal loss in multiple gestation was difficult. However, recent reports of serial ultrasound examinations of pregnant women have documented the "disappearance" of at least one of two gestational rings. Furthermore, the number of twins observed at delivery was significantly less than the number of twin conceptions originally identified by ultrasound during the first trimester. These observations led to the concept of the "vanishing twin" [8,10,13,15,17,20,22,35,41]. In order to obtain reference and personal data on this subject, we reviewed the literature and corresponded with members of the International Society for Twin Studies and obstetricians affiliated with Northwestern University Medical School, Chicago, Illinois. The nine studies that have documented this phenomenon cite "disappearance" rates ranging from 0% to 78%, depending on patient population and timing of ultrasonography [8,10,13,15,17,20,22,35,41]. Several explanations are offered: physiological mechanisms of "disappearance" (resorption or formation of a blighted ovum or fetus papyraceus), artifactual error, incomplete scanning technique, and poor quality ultrasound equipment. The only complication thus far associated with "disappearance" of a fetus is slight vaginal bleeding.

Abortion, Spontaneous↗
PubMed1980

The Northwestern University multihospital twin study. I. A description of 588 twin pregnancies and associated pregnancy loss, 1971 to 1975.

Five hundred eighty-eight women who were delivered of twins at 13 hospitals affiliated with the Northwestern University Medical School or its outreach institutions between 1971 and 1975 were studied. Eighty-six of the infants did not survive the pregnancy, delivery, or the first week post partum. Maternal demographic and obstetric characteristics are outlined. Infants are categorized by birth order and by birth weight. The mean weight (and standard deviation) of first twins was 2,388 gm (+/- 742 gm) and that of second twins was 2.314 gm (+/- 766 gm). The rate of pregnancy wastage was highest in mothers who were under 20 years of age, who were of low parity, and who were delivered prior to the physiologic maturation of the fetus. The crude mortality rate of twin 1 was 6.1/100 versus 8.5/100 for twin 2. The causes of death in all infants over 2,000 gm are listed. All pregnancy losses are categorized into unavoidable deaths (26.6%), probably not avoidable deaths (59.4%), and possibly avoidable deaths (13.9%).

Adolescent↗