Daniel M. Strickland

The relationship between abortion in the first pregnancy and development of pregnancy-induced hypertension in the subsequent pregnancy

The relation between pregnancy-induced hypertension and reproductive history was assessed in 29,484 women receiving obstetric care at Parkland Memorial Hospital. The incidence of pregnancy-induced hypertension was 25.4% in primigravid women, somewhat lower (22.3%) in women whose only previous pregnancy terminated in abortion, and much lower (10%) in women who carried two or more successive pregnancies to viability.

The human placenta: A major source of prostaglandin D2

Abstract Human intra-uterine tissues have been superfused and prostaglandin D2 (PGD2) has been measured in the effluents by a specific radioimmunoassay. The rate of production of PGD2 by placenta was three fold greater than that by amnion, chorion laeve or decidua vera. It is suggested that PGD2 produced by the placenta may play an important part in the regulation of utero-placental hemodynamics in human pregnancy.

Cost-effectiveness of intrapartum screening and treatment for maternal group B streptococci colonization

Early-onset neonatal group B streptococci infection occurs in two cases per 1000 live births in the United States and is associated with a mortality rate greater than 20%. Nearly 30% of infected infants have concomitant meningitis and half suffer permanent neurologic damage. Group B streptococci also account for at least 20% of postpartum metritis. The annual cost of group B streptococci infection in the United States is conservatively estimated at nearly 2000 neonatal deaths and greater than

Uterine contraction pressures with oxytocin induction/augmentation.

500 million, excluding the costs of long-term neurologic handicaps. Intrapartum chemoprophylaxis with ampicillin is effective in curtailing transmission of group B streptococci from mother to infant. Methods have been developed to identify maternal colonization before delivery. We applied principles of decision analysis to evaluate cost-effectiveness of intrapartum screening for maternal group B streptococci colonization with various reported methods in cohorts of low- and high-risk women. In the United States intrapartum screening for group B streptococci is cost-effective and offers the potential to avert a significant number of neonatal deaths and postpartum infections.

A sensitive radioimmunoassay for 11-deoxy-13,14-d i h yd ro-15-k eto-11,16-cycloprostaglandin E2: Application as an index of prostaglandin E2 biosynthesis during human pregnancy and parturition

&NA; Uterine contraction pressures were quantified (in Montetevideo units) in 109 women at term gestation who received oxytocin for induction or augmentation of labor and whose labor resulted in a spontaneous vaginal delivery. Newborn five‐minute Apgar scores were greater than or equal to 8 in 108 of the 109 neonates, and no immediate neonatal morbidity was attributable to the oxytocin stimulation of labor. Women undergoing oxytocin induction had significantly greater uterine contraction pressures than those with oxytocin augmentation. During oxytocin induction 91% of women achieved at least 200 to 224 Montevideo Units and 40% at least 300 Montevideo units versus 77 and 7.7%, respectively, during augmentation of labor. With concurrent fetal monitoring these levels of uterine activity should be sought before consideration of a cesarean delivery because of presumed cephalopelvic disproportion or failure to progress. (Obstet Gynecol 68:305, 1986)

Umbilical cord pH and PCO2: effect of interval from delivery to determination.

A radioimmunoassay for 11-deoxy-13, 14-dihydro-15-keto-11, 16-cycloprostaglandin E2 (PGEM-II) is described. At pH 10.5, in the presence of albumin, 13, 14-dihydro-15-keto-prostaglandin E2 (PGEM-I) is transformed quantitatively into PGEM-II. Hence, after plasma samples are subjected to this transformation procedure, PGEM-II can be measured in such samples and be a true reflection of PGEM-I production and thereby prostaglandin E2 (PGE2) biosynthesis. The antiserum raised against PGEM-II is minimally cross-reactive with all prostaglandins tested (less than 0.01%). The mean least detectable mass of PGEM-II is 0.8 pg and the mean mass of added PGEM-II required to displace zero-point binding by 50% is 16.6 pg. The assay meets all the standard criteria for accuracy, reproducibility and parallelism. Concentrations of PGEM-II measured by this assay in peripheral plasma from men and nonpregnant women are similar to those reported for PGEM-I after measurements by gas chromatography - mass spectrometry. Plasma concentrations of PGEM-II in men were greater than in nonpregnant women. PGEM-II in increased concentration was found in early pregnancy although concentrations declined in the third trimester until labor when a significant increase was found. Concentrations of PGEM-II in umbilical venous plasma were significantly greater than those in maternal plasma.

Measurement of 13,14-dihydro-15-keto-prostaglandin F2α an[6-keto-prostaglandin F1α in plasma by radioimmunoassay without prior extraction or chromatography

Determinations of umbilical blood pH and PCO2 can be useful for correlating intrapartum fetal heart rate patterns, intrapartum samples of scalp blood, and Apgar scores, for the retrospective evaluation of the management of a particular labor. Occasionally, such data can indicate and clarify needed resuscitative measures and intensive neonatal observation. Cumbersome techniques have been described for the handling of specimens of cord blood to ensure an accurate determination. This study was performed to determine the effect on cord blood pH and PCO2 of room temperature and time from delivery. One hundred five cord venous or arterial determinations had a linear pH decrease versus time at room temperature. The regression slope was -3.66 X 10(-4) per minute with a standard deviation of 1.37 X 10(-2). The PCO2 showed only a slight increase with time at room temperature, although the scatter was high, with a standard deviation of 3.8 torr. The conclusion is that samples of cord blood drawn for determination of pH and PCO2 can be kept at room temperature in plastic syringes for up to 30 minutes without significant alteration in these values, i.e., pH decrease no greater than 0.04 unit (p less than 0.05).

Prostaglandin biosynthesis stimulatory and inhibitory substances in human amniotic fluid during pregnancy and labor

A method is described whereby 13,14-dihydro-15-keto-prostaglandin F(2α) and 6-keto-prostaglandin F(1α) can be measured by radioimmunoassay in human plasma directly. The results of measurements obtained by this method are both reproducible and accurate and are in good agreement with results reported using different techniques.

Amniotic fluid prostaglandin D2 in spontaneous and augmented labor

Human amniotic fluid has been separated into two fractions; one fraction inhibits prostaglandin biosynthesis and the other fraction is stimulatory. The activity of the stimulatory fraction increased with increasing gestational age and was greater still during labor. The activity of the inhibitory fraction decreased with increasing gestational age and was smaller still during labor. We speculate that these changes may play a significant role in parturition.

Endogenous stimulant of prostaglandin endoperoxide synthase activity in human amniotic fluid

Prostaglandin D2 (PGD2) was quantified in human amniotic fluid obtained from women in various phases of the first stage of spontaneous labor, augmented labor, and induced labor. PGD2 increased significantly only in late labor in the spontaneous and augmented labor groups.