Low dose aspirin in pregnancy: a clinical and biochemical study of effects on the newborn

Prenatal low-dose aspirin and neurobehavioral outcomes of children born very preterm

OBJECTIVE

Low-dose aspirin (LDA) given during pregnancy may alter brain development in very preterm infants. We report the short- and long-term outcomes of very preterm infants according to LDA treatment.

PATIENTS AND METHODS

Data were from the Etude Epidemiologique des Petites Ages Gestationnels (EPIPAGE) cohort study, which included all infants born before 33 weeks of gestation in 9 French regions in 1997. This study was restricted to 656 children who were born to 584 women with an obstetric history of placental vascular disease or with chronic hypertension or renal or autoimmune diseases. The main outcome measures were mortality, cerebral lesions, and outcome at 5 years of age, which were measured by a diagnosis of cerebral palsy; behavioral difficulties, which were assessed with the Strength and Difficulties Questionnaire; and cognitive impairment, which was measured by the mental processing composite scale of the Kaufman Assessment Battery for Children (an IQ-equivalent measure of cognitive ability in 2 dimensions: sequential and simultaneous processing scores).

RESULTS

LDA treatment was administered to 125 of 584 (21%) mothers and was not significantly associated with mortality, cerebral lesions, cerebral palsy, or global cognitive impairment of the children at 5 years of age. The proportion of low simultaneous processing scores (<70) was lower in the group with LDA (7% vs 19% without LDA; P = .04). This association was not significant after adjustment for propensity score, prognostic factors, and social class (adjusted odds ratio [aOR]: 0.59 [95% confidence interval (CI): 0.17-2.06]). LDA treatment was associated with a reduction, at the limit of significance, in total behavioral difficulties (aOR: 0.44 [95% CI: 0.19-1.02]) and hyperactivity (aOR: 0.43 [95% CI: 0.17-1.05]).

CONCLUSIONS

LDA was not associated with adverse neonatal or long-term outcomes. Moreover, the results suggest that LDA may be associated with a reduction in neurobehavioral difficulties. More research is needed to assess the effects of aspirin alone or combined with other neuroprotective agents.

Platelet activation in pregnancy-induced hypertension

BACKGROUND

Although excess platelet activation, as indicated by increased plasma beta thromboglobulin (beta-TG), has been shown in pregnancy-induced hypertension (PIH), platelet adhesion, platelet morphology and a comparison of platelet and soluble (plasma) levels of the adhesion molecules P-selectin (pPsel and sPsel, respectively) have not been studied.

METHODS

We conducted a cross-sectional study of 35 consecutive women with PIH (age 31+/-6 years), 31 consecutive women with normotensive pregnancies (age 29+/-5 years) and 30 normotensive non pregnant women (age 30+/-5 years). Platelet adhesion was studied in vitro by binding to fibrinogen-coated microwells, platelet morphology [mass and volume by flow cytometry], whole-platelet P-selectin (pPsel) by ELISA of the lysate of 2 x 10(8) cells, and the plasma markers soluble P-selectin (sP-sel) and beta-TG, by ELISA.

RESULTS

The women with PIH had significantly raised sPsel, pPsel and (as expected) beta-TG (all p<0.05), when compared to the normotensive pregnant women and controls. However, in PIH platelet adhesion was similar to that in the normotensive pregnancy, but still higher than the normal controls (p<0.001). There was no difference among the three groups with respect to platelet mass and volume. pPsel and platelet adhesion correlated with gestational age and with systolic and diastolic blood pressure (all p<0.05).

CONCLUSIONS

Increased platelet activation and adhesion develop during normal pregnancy, with some indices being further altered in PIH.

Low-dose aspirin in pregnancy: maternal and neonatal aspirin concentrations and neonatal prostanoid formation

OBJECTIVE

To evaluate maternal and neonatal plasma concentrations of acetylsalicylic acid and salicylic acid and the neonatal endogenous prostanoid formation during low-dose aspirin prophylaxis (LDA; 100 mg daily) in pregnant women.

METHODS

Concentrations of acetylsalicylic acid and salicylic acid in maternal plasma after at least 4 weeks of LDA (n = 14) and in umbilical cord plasma of newborns after maternal LDA (n = 7) were determined by gas chromatography-mass spectrometry. Platelet and renal formation of thromboxane A2 and the formation of prostaglandin E2 and prostacyclin were evaluated in vivo by quantification of index metabolites in plasma and urine by gas chromatography-mass spectrometry in neonates after maternal LDA (n = 14) and in a control group.

RESULTS

In the pregnant women, acetylsalicylic acid and salicylic acid concentrations rapidly increased after ingestion of LDA. Acetylsalicylic acid was completely eliminated within 4 hours, whereas salicylic acid was detected with low concentrations at 18 and 21 hours after dosing. In the neonates, acetylsalicylic acid was not detected. Salicylic acid was detected in 1 infant only. Platelet thromboxane A2 formation in the newborn infants was significantly suppressed but recovered within 2 to 3 days after discontinuation of LDA. Renal thromboxane A2 formation and the formation of prostaglandin E2 and prostacyclin were not affected by LDA.

CONCLUSION

In pregnant women who are treated with LDA, acetylsalicylic acid is not completely inactivated in the portal circulation but reaches the uteroplacental circulation and exerts antiplatelet effects in the fetus and newborn.

Fetal intracranial hemorrhage due to antenatal low dose aspirin intake

Antenatal intake of low dose aspirin is advised for prevention of pregnancy induced hypertension, intrauterine growth retardation and pre-term labour. Aspirin has an anticoagulant effect due to its action on Cyclo-oxygenase and vitamin K dependent coagulation factors. It can readily cross the placental barrier and be a potential cause for bleeding tendency in the fetus. Fetal intracranial hemorrhage, following low dose aspirin administration in a mother and subsequent effect after delivery is being reported.

Umbilical cord serum levels of thromboxane B2 in term infants of women who participated in a placebo-controlled trial of low-dose aspirin

OBJECTIVE

Our aim was to quantify thromboxane B2 (TXB2) in umbilical cord serum of term infants of nulliparous, low-risk women who were randomly assigned to either placebo or low-dose (60 mg) aspirin (ASA) on a daily basis from 24 weeks' gestation through delivery as part of a randomized clinical trial for prevention of preeclampsia.

METHODS

Umbilical cord sera from 230 singleton, term infants whose mothers were involved in our low-dose ASA trial were assayed for TXB2, the stable metabolite of thromboxane A2, without knowledge of treatment or outcome data. The data were related to assigned treatment group, longitudinal pattern of maternal serum TXB2 levels, and other maternal and newborn characteristics. The data also were analyzed according to whether or not maternal serum levels of TXB2 at 29-31, 34-36, and delivery were reduced > or =50% compared to values prior to initiation of the trial.

RESULTS

Umbilical cord TXB2 levels (ng/ml, mean +/- SE) were significantly lower at term in the ASA group (36.1 +/- 3.3, n = 111) than in the placebo group (56.6 +/- 5.7, n = 119; P = 0.002). Umbilical cord TXB2 levels were correlated to those in maternal serum at delivery in the ASA group (r = 0.3441; P = 0.0005) but not in the placebo group (r = 0.0626; P = 0.53). Regardless of assigned treatment group, infants whose mothers had a > or =50% longitudinal reduction in serum TXB2 had lower umbilical cord TXB2 levels (39.2 +/- 3.6, n = 114) than infants whose mothers had <50% reductions in TXB2 (54.6 +/- 5.9, n = 116; P = 0.027). Birthweights of these infants correlated inversely (r = 0.1678, P = 0.017) with maternal serum TXB2 at delivery but not to umbilical cord TXB2 levels; the best correlation between birthweight and maternal serum TXB2 was noted in pregnancies assigned to receive placebo (r = -0.2558, P = 0.009).

CONCLUSIONS

Umbilical cord serum levels of TXB2 1) are reduced in instances of long-term maternal ingestion of ASA, 2) correlate well with maternal serum levels of TXB2 at delivery when there is evidence for consistent maternal use of ASA, but 3) do not correlate with maternal serum TXB2 levels when there is no evidence for frequent maternal ingestion of cyclooxygenase inhibitors. These data suggest that the capacity for platelet production of TXA2 in fetal and maternal compartments are regulated independently. Finally, there is an inverse relationship between maternal serum TXB2 levels at delivery and birthweight of newborn infants that is most evident among the pregnancies assigned to placebo and also among pregnancies in which there was little evidence to suggest a pattern of cyclooxygenase inhibitor use during pregnancy.

Primary stent implantation for acute myocardial infarction during pregnancy: use of abciximab, ticlopidine, and aspirin

Recent evidence suggests that coronary stenting and the use of antiplatelet agents during coronary interventions will improve the outcome of patients with acute myocardial infarction (AMI). We describe the management of AMI in a 30-year-old woman, 38 weeks pregnant, with primary stenting and antiplatelet agents.

Dose-related effects of low dose aspirin on hemostasis parameters and prostacyclin/thromboxane ratios in late pregnancy

BACKGROUND

The purpose of this study was to determine which low dose of low dose aspirin (LDA) optimized the urinary prostacyclin (PGI2)/thromboxane (TXA2) ratio and minimized evidence of platelet aggregation during normal late pregnancy.

METHODS

Twelve women with uncomplicated singleton pregnancies between 28 and 34 weeks gestation participated in a randomized blinded study. Blood samples for salicylate levels were obtained pretreatment, 4 hours and 7 days after administration of placebo, 20mg, 40mg or 80mg of aspirin. Twenty-four hour urine specimens collected at the same intervals were assayed for PGI2 and TXA2 metabolites. In addition, bleeding time and platelet aggregation studies were performed prior to and after 7 days of LDA or placebo.

RESULTS

A dose-related increase in bleeding time occurred with 40 mg and 80 mg of LDA, but not with the 20 mg dose or placebo. Platelet aggregation studies changed progressively from a normal baseline to abnormal with an increasing dose of LDA. The PGI2/TXA2 ratio increased with aspirin doses as low as 20mg, with a decrease in TXA2 metabolites but not in PGI2 metabolites. Serum salicylate was not detectable in any sample from any patient.

CONCLUSION

There are dose-related changes in platelet aggregation and bleeding times with progressively increasing doses of LDA. A lower dose of LDA, such as 20-40 mg per day, may be as efficacious as higher doses in the prophylaxis of pre-eclampsia in high risk populations.

Decrease in severity of intrauterine growth retardation in subsequent pregnancies

OBJECTIVE

Intrauterine growth retardation (IUGR) is likely to recur in a subsequent pregnancy. We investigated the obstetric features of recurrent cases and the severity of IUGR by comparing initial and subsequent deliveries.

METHODS

From a total of 12,567 deliveries, 95 women who were delivered of small-for-gestational-age (SGA) infants and who became pregnant again within 5 years, were enrolled. A retrospective, comparative study of recurrent and non-recurrent groups was performed.

RESULTS

Twenty-two of ninety-five women gave birth to SGA infants again, and a relatively high risk of recurrence was confirmed, but no single recurrence-associated features were revealed. Within the recurrent group, the degree of IUGR was more severe in only five cases in the subsequent pregnancy.

CONCLUSIONS

IUGR tends to recur, but does not increase in severity in most cases. We conclude that there is no need for excessive concern about the recurrence of IUGR.