Chronic hypertension in pregnancy.

Women with chronic hypertension who are considering pregnancy should undergo extensive evaluation and work-up prior to conception. This evaluation is important to establish the cause and severity of the hypertension. The patient should be seen early in pregnancy and counseled regarding the possible adverse effects of hypertension and the importance of adherence to prenatal visits and prescribed medications. Patients classified to have high-risk hypertension are at increased risk for significant maternal and perinatal complications. These patients should have intensive antenatal follow-up and will require antihypertensive therapy irrespective of the severity of the hypertension. In contrast, in women with mild uncomplicated hypertension, good perinatal outcome is expected with proper obstetric care, without the use of antihypertensive drugs. Finally, most of the poor perinatal outcome in such pregnancies is related to the development of superimposed preeclampsia.     

Management of preeclampsia.

Prompt hospitalization is the optimum management of all patients with preeclampsia. Expectant management is possible in most patients remote from term. The success rate of expectant management will depend on both fetal gestational age and the state to which the disease has progressed at the time of hospitalization. Maternal and perinatal complications are increased significantly in patients with severe preeclampsia and in those with the HELLP syndrome. Thus, these patients should be managed only at tertiary care centers.     

Low-dose aspirin in pregnancy

In a prospective study, we evaluated the effects of low-dose aspirin on maternal and neonatal plasma 6-keto-prostaglandin (PG) F1 alpha concentration, platelet aggregation, platelet thromboxane production, and neonatal transitional circulation. Forty women, at a mean (+/- SD) of 37 +/- 2 weeks' gestation, were randomized to receive (N = 10 each) placebo or 20, 60, or 80 mg of aspirin per day until delivery. Maternal serum 6-keto-PGF1 alpha levels were not affected by these doses of aspirin, whereas thromboxane B2 generated during clotting of maternal blood was decreased significantly by 60 and 80 mg of aspirin by 1 week of therapy. Maternal platelet thromboxane B2 production in response to adenosine diphosphate or collagen was reduced 98% by the 80-mg dose after 1 week of aspirin therapy. The 60-mg dose reduced maternal platelet thromboxane B2 production in response to adenosine diphosphate (50% decrease) or collagen (60% decrease) after 1 week of treatment, a nonsignificant difference. After 2 weeks of treatment with 60 mg of aspirin, platelet thromboxane B2 production induced by both collagen and adenosine diphosphate was inhibited significantly (P less than .01). Neonatal serum levels of 6-keto-PGF1 alpha and thromboxane B2 were not affected by any doses of aspirin. Further, neonatal platelet aggregation in response to platelet stimulation by collagen and adenosine diphosphate was not inhibited. All neonates had echocardiographic evidence of a patent ductus arteriosus, and noninvasive estimates of pulmonary arterial pressure were similar among the groups of infants.(ABSTRACT TRUNCATED AT 250 WORDS)     

Baking powder pica mimicking preeclampsia.

We report a case of baking powder pica during pregnancy that was associated with maternal hypertension, hypokalemia, and elevated liver function tests. After discontinuation of baking powder ingestion and correction of electrolyte abnormalities, the blood pressure and the liver function tests normalized.     

Hepatic histopathologic condition does not correlate with laboratory abnormalities in HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count)

OBJECTIVE: Our objective was to categorize the histologic findings in the liver in patients with HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) and to correlate these findings with the severity of clinical laboratory abnormalities. STUDY DESIGN: Eleven patients with laboratory criteria for HELLP syndrome who required cesarean delivery underwent needle biopsy of the liver under direct visualization. RESULTS: Eight patients had periportal hemorrhage, and six had fibrin deposition. Fatty infiltration was seen in four, one with large-droplet fat, three with microvesicular fat. There was no statistically significant correlation between the severity of the histologic findings of periportal hemorrhage and fibrin deposition and the clinical laboratory findings. Fatty infiltration did not correlate with the severity of the HELLP syndrome's histologic condition, but, in contrast, did correlate with thrombocytopenia and aminotransferase elevations. CONCLUSIONS: Laboratory abnormalities do not accurately reflect the severity of the underlying histopathologic condition in HELLP syndrome. We propose that all patients with HELLP syndrome, regardless of the degree of their laboratory abnormalities, be treated aggressively, primarily with delivery.     

The relationship between experimentally determined litter size and maternal blood pressure in spontaneously hypertensive rats

Pregnancy lowers blood pressure in hypertensive rats. To evaluate the role of the conceptus in maternal blood pressure regulation, we measured the changes in systolic blood pressure b (by tail-cuff plethysmography) throughout gestation and mean arterial pressure, cardiac output, and organ blood flows (with radioactive microspheres) on postmating day 21 for calculation of total peripheral and organ vascular resistances in spontaneously hypertensive rats with litter size surgically adjusted to 0 to 10 conceptuses on postmating day 7. Blood pressure remained elevated in those rats with zero fetuses but decreased during the last week of pregnancy in those rats with three or more fetuses. The magnitude of the decrease was directly related to litter size. At term, cardiac output was positively correlated (r = 0.61; p less than 0.001), whereas mean arterial pressure and total peripheral resistance were negatively correlated (r = -0.74; p less than 0.001 and r = -0.79; p less than 0.001, respectively) with litter size. Resistances of all the vascular beds in the body, except the kidneys, spleen, and hepatic artery were also negatively correlated with fetal number. Thus pregnancy is characterized by a generalized maternal vasodilation, and the fetal/placental unit may play a significant role in modulating maternal vascular tone.     

Treatment in an obstetric intensive care unit

A three-bed intensive care unit was opened in the labor and delivery area of a city-county hospital having approximately 7500 deliveries annually. The utilization rate of 0.9% and the severity of illness were sufficient to justify such a unit. Main indications for admission were hypertensive disorders (46%), massive hemorrhage (10%), and medical problems of pregnancy (44%). Identifiable benefits of the unit were as follows: (1) Intensive observation and organization allowed for prevention of early recognition and treatment of complications; (2) familiarity with invasive monitoring permitted personnel to exert prompt, rational treatment of hemodynamically unstable patients; (3) continuity of care was improved before and after delivery; (4) residents and fellows learned a great deal about intensive care and the management of rare medical complications of pregnancy. We conclude not only that critically ill pregnant women can be managed successfully in an obstetric intensive care unit but also that critical care is a bona fide part of obstetric practice and has been incorporated into our training program.     

Fetus-placenta-newborn

OBJECTIVE: Our purpose was to determine whether third-trimester maternal serum α-fetoprotein predicts adverse perinatal outcome and whether use of both second- and third-trimester maternal serum α-fetoprotein enhances the positive predictive value for various abnormal outcomes.STUDY DESIGN: A cohort study with obstetric outcome assessed by chart analysis after delivery was performed at Regional Medical Center (Memphis, Tennessee), a hospital staffed by university-based physicians saving a large urban population with many indigent patients. A total of 650 women attending prenatal clincis in the above setting with a singleton pregnancy without a neural tube defect, contributing a maternal blood samples in both the second and third trimesters, and delivered in the above hospital participated. Various pregnancy outcomes were correlated with maternal serum α-fetoprotein levels in the second the third trimesters and in both.RESULTS: In the third trimester no significant associations were found between maternal serum α-fetoprotein elevations and pregnancy complications. In the second trimester elevation (≥2.0 multiples of the median) were, by contrast, significantly associated with preterm premature rupture of the membranes, preterm birth, and low birth weight. No association was found with certain other complications. When second-trimester data were grouped according to the types of complications occurring in individual women, only preterm premature rupture of the membrane proved statistically significant.CONCLUSIONS: Second-trimester but not third-trimester maternal serum α-fetoprotein is significantly elevated with preterm premature rupture of the membranes, preterm birth, and low birth weight; in this conhort study no association was found with preeclampsia, oligohydramnios, or polyhydramnios.     

Efficacy of outpatient induction with low-dose intravaginal prostaglandin E2: A randomized, double-blind, placebo-controlled trial

OBJECTIVE: Our purpose was to determine whether a protocol for outpatient induction is safe and effective for initiating labor.STUDY DESIGN: A randomized, double-blind, a placebo-controlled trial was performed with 100 low-risk patients having well-dated pregnancies. Women with a Bishop score ≤6 at 38 to 40 weeks' gestation were administered either 2 mg of intravaginal prostaglandin E₂ gel or placebo for 5 consecutive days as outpatients while undergoing fetal monitoring.RESULTS: The median interval from randomization to delivery was 4 days in the prostaglandin E₂ group (range 0 to 28 days) and versus 10 days in the placebo group (range 0 to 26 days, p = 0.002). Twenty-seven of 50 patients (54%) in the prostaglandin E₂ group were admitted for labor during the dosing interval compared with 10 placebo-treated patients (20%, p = 0.001). The mean gestational age at delivery was significantly reduced in the treatment group (39.9 ± 1.0 weeks vs 40.5 ± 0.99 weeks, p = 0.003) as was the incidence of postdates pregnancy (40% vs 66%, p = 0.016). Hyperstimulation was observed in one prostaglandin E₂-treated patient, but no intervention was required.CONCLUSIONS: Outpatient low-dose prostaglandin E₂ gel administration is effective for initiating labor in patients with an unfavorable cervix and appears safe if performed with adequate monitoring.     

Nifedipine does not adversely affect uteroplacental blood flow in the hypertensive term-pregnant rat

The short-term effect of the calcium channel blocker, nifedipine, on maternal hemodynamics and organ perfusion was investigated in 12 hypertensive term-pregnant, spontaneously hypertensive rats by means of the radioactive-labeled microsphere technique. The normal fall in blood pressure during pregnancy was prevented by reducing litter size to two conceptuses on day 7 of gestation. Nifedipine (200 micrograms/kg) effectively lowered mean arterial pressure 25% by decreasing total peripheral resistance 38%. Cardiac output was increased 15%. Blood flows to the splanchnic region and the reproductive organs were increased after nifedipine administration. The increase in blood flow to the reproductive organs was the result of increased ovarian and uterine wall perfusion caused by large reductions in vascular resistances. Placental blood flow was not significantly altered, but resistance was decreased. Thus, the use of nifedipine to lower maternal blood pressure in pregnancy complicated by extreme hypertension does not necessarily decrease uteroplacental perfusion.