Siva Thiagarajah

Thrombocytopenia in preeclampsia associated abnormalities and management principles

Severe thrombocytopenia, abnormal liver function, and renal dysfunction may occur as manifestations of preeclampsia. Failure to recognize that this cluster of abnormalities represents a form of preeclampsia may result in erroneous initial diagnoses. Management of 13 such patients has shown a direct correlation between the degree of thrombocytopenia and the measures of liver dysfunction. Platelet counts and liver functions improved prior to delivery in five patients treated with corticosteroids. Management should be directed toward investigation and correction of deranged physiology and appropriate monitoring of maternal-feto-placental status. Early delivery is indicated in patients with progressive thrombocytopenia and in those with evidence of fetal maturity or distress. Provided that the disease process remains stable, consideration should be given in cases of fetal immaturity, to the use of betamethasone therapy. The occurrence of severe thrombocytopenia in 20% of neonates should be a consideration in selecting the mode of delivery.

The use of magnesium sulfate as the primary tocolytic agent to prevent premature delivery

The efficacy of magnesium sulfate was evaluated as the primary tocolytic agent in the managment of patients at risk for premature delivery. One hundred ninety-two patients determined to be 36 weeks’ gestation or less were treated. One hundred seven patients (55.7%) received an additional oral beta-mimetic agent once labor was arrested. One hundred nineteen patients had intact membranes and 73 patients had ruptured membranes. Delay of delivery for 48 hours or longer was achieved in 70.6% of the patients with intact membranes and 60.2% of patients with ruptured membranes. Intervening obstetric complications, maternal morbidity, and neonatal septic and respiratory morbidity were increased in patients with ruptured membranes compared to patients with intact membranes. Magnesium sulfate is considered to be an effective tocolytic agent having minimal adverse effects in managing patients at risk for premature delivery. Its use in patients with ruptured membranes, as with any tocolytic agent, remains controversial.

Ectopic pregnancy: Current clinical trends

During the 16 year period ending in November, 1978, 191 cases of ectopic pregnancy were managed at the University of Virginia Hospital. The overall incidence was 1/126 deliveries but during the last 3 years of the study the incidence was 1/60 deliveries. Only 56 patients have had a subsequent conception. Thirteen have had a recurrent ectopic implantation. Only 36 women (23.7% of those available for follow-up) have had subsequent term pregnancies. Ectopic pregnancy continues to be a major gynecologic problem and the potential for subsequent fertility is poor.

Magnesium sulfate and ritodrine hydrochloride: Systemic and uterine hemodynamic effects

Effects of magnesium sulfate and ritodrine hydrochloride on cardiovascular physiologic characteristics were studied in 70 human subjects treated for preterm labor. Systemic and uterine hemodynamic effects were investigated in five pregnant rhesus monkeys. Systolic blood pressure was minimally affected by either agent. Diastolic pressure, while not affected by magnesium sulfate, decreased 26.3% during ritodrine therapy. Maternal and fetal heart rates were minimally affected by magnesium sulfate. Ritodrine increased maternal and fetal heart rates significantly. In the monkeys, magnesium sulfate increased uterine and placental blood flows (by the microsphere technique) but failed to alter cardiac output. Ritodrine produced an increase in cardiac output but decreased perfusion pressure. Placental blood flow decreased by an average of 27.6%. Ritodrine would therefore seem contraindicated with a compromised fetal environment. Magnesium sulfate, by not altering perfusion pressure, may have a beneficial effect on uterine hemodynamics. These specific and distinct differences in cardiovascular and hemodynamic effects should be considered when either magnesium sulfate or ritodrine is selected as a tocolytic agent.

The role of ultrasonography and amniocentesis in the evaluation of pregnancies at risk for neural tube defects

To assess the relative efficacy of amniocentesis versus targeted (detailed) ultrasonography, 225 patients referred because of an elevated maternal serum alpha-fetoprotein level (79.6%) or a family history of neural tube defect (20.4%) were evaluated. Ultrasonographic examination alone detected all 26 fetal abnormalities (11 cases of anencephaly, 10 cases of open spina bifida, and five other anomalies). Twenty-eight patients declined amniocentesis; all had normal pregnancy outcomes. Of the 167 patients with apparently normal fetal anatomy by sonography, seven had elevated alpha-fetoprotein levels but no acetylcholinesterase in the amniotic fluid. Six of these pregnancies resulted in normal infants; one infant had congenital nephrosis. The remaining 160 patients had normal sonograms with normal amniotic fluid alpha-fetoprotein levels and no fetal malformations at delivery. Although these results suggest that targeted ultrasonography by experienced personnel is a reasonable alternative to amniocentesis in evaluations for neural tube defects, the availability, cost-effectiveness, and diagnostic accuracy of this approach must be well documented in large prospective studies.

Fetal evaluation by percutaneous blood sampling

Percutaneous umbilical blood sampling (cordocentesis) provides direct access to the fetal circulation in the second and third trimesters of pregnancy. Seventeen patients underwent this procedure between December 1985 and December 1986 for evaluation of a variety of clinical situations, including nonlethal fetal abnormalities detected by ultrasound, equivocal results of amniocentesis, nonimmune fetal hydrops, and isoimmune disorders. Our experience confirms the efficacy of the procedure and suggests that it may become an important tool for fetal assessment and therapy.

The significance of fetal heart rate decelerations during nonstress testing

Over a 9-month time span, eight gravid women at high risk had fetal heart rate decelerations on nonstress tests (NSTs). This form of antepartum evaluation, the standard at our institution, was performed 918 times on 476 women during this period. Decelerations were required to be between 1 and 10 minutes in duration and less than 90 bpm, or greater than 40 bpm below baseline, for inclusion. Of the eight women (1.7% of the total tested), four had reactive and four nonreactive NSTs. All eight had contraction stress tests (CSTs) that were negative by definition. Of four women allowed to labor, two (50%) required cesarean section for fetal distress. Two instances of fetal death (25%) occurred during observation periods of 36 and 48 hours. Two infants were growth retarded, and two had abnormal cord positions. NSTs showing decelerations of this type, regardless of reactivity or of follow-up CST, are abnormal and should be viewed with alarm. In term pregnancy, such fetuses should be delivered. In preterm pregnancy with nonreactive NSTs, decelerations may also be valid grounds for delivery. Some discrimination is possible in preterm pregnancies when the NST is reactive.

Diagnosis and management of prenatally detected myelomeningocele: A preliminary report

Our experience with 23 cases of fetal myelomeningocele provides preliminary information on the outcome of these infants diagnosed in utero and managed by a multidisciplinary team. The mean age of diagnosis was 23.7 weeks (range, 16 to 34 weeks). Mean gestational age at delivery was 36.9 weeks in the 14 patients who elected to continue their pregnancies. None of the 11 infants with lumbosacral or sacral lesions developed significant ventriculomegaly before term. Of the three patients diagnosed with thoracolumbar lesions, two had progression of ventriculomegaly necessitating early delivery at 32 to 34 weeks of gestation. These preliminary findings suggest that a coordinated prenatal and neonatal approach appears to result in a favorable prognosis for infants with myelomeningocele, but that neonatal complications are common, requiring careful monitoring and aggressive management.

Profound hypotension complicating magnesium therapy

Two preeclamptic women became profoundly hypotensive while receiving magnesium sulfate. No evidence of toxic levels was present in either. In both, preeclampsia-induced hypovolemia was extreme. That nontoxic magnesium levels can cause severe hypotension is an alarming possibility. Acknowledgment of this complication and expeditious reversal of the problem is essential.

Prolactin secretion by human chorion-decidua in vitro: Influences of mode of delivery and agents that modify prostaglandin synthesis

Prolactin production by human decidua was examined with the use of a short-term tissue explant system. Decidua obtained after normal spontaneous vaginal deliveries produced significantly more prolactin than did tissue obtained after elective repeat cesarean section deliveries in the absence of labor (P less than 0.005). Cytosolic prolactin levels did not differ between the two delivery modes. Oxytocin (4.3 X 10(-11) M to 4.3 X 10(-6) M) and eicosatetraenoic acid (10(-7) M to 10(-4) M) had no effect on prolactin production or storage by decidual tissue. Indomethacin at 10(-4) M reduced only levels of stored prolactin but had no effect on stored or produced prolactin at lower concentrations (10(-7) M to 10(-5) M). Arachidonic acid (10(-4) M) suppressed both production and storage of prolactin (P less than 0.05). Decidual tissue from the two delivery modes did not differ in response to the above agents. Although the exact mechanism(s) remains obscure, these results indicate decidual prolactin production is altered by some aspect of labor. The possible involvement of prostaglandin precursors in mediating this production cannot be excluded.