SCORPION ENVENOMATION SYMPTOMS IN PREGNANT WOMEN

Scorpion envenomation is common in many countries; however, its effects on pregnancy are still unclear. In the present paper, we described the effects of scorpion envenomation on pregnant patients. A retrospective study was carried out considering the clinical and laboratory exams of patients admitted to the emergency room of Habib Bourguiba Hospital, Sfax, Tunisia, from 1990 to 2004. Variability of these clinical and laboratory profiles according to maternal age, gestational age and number of previous parities was also discussed. Among 167 scorpion-envenomed women, age ranged from 17 to 42 years, 7.18% were pregnant. These presented symptoms similar to those of non-pregnant women envenomed by scorpions. Two pregnant patients developed intense pelvic pain and one manifested vaginal bleeding. Although the studied parameters showed non-significant differences, we could conclude that scorpion envenomation may lead to abnormal uterine contraction probably causing preterm delivery. Maternal disturbances induced by scorpion envenomation may influence the fetus development. The effects were more severe in the second trimester of pregnancy.


INTRODUCTION
Scorpion envenomation is a common occurrence in tropical and sub-tropical countries (7).Its clinical manifestations are largely varied, and its pathophysiology essentially includes nervous (17), cardiovascular (17,32) and muscular systems disturbances.Little is known about the effect of scorpion envenomation on human pregnancy (16).In the present study, we described the signs and symptoms of scorpion-envenomed pregnant women based on a retrospective study.

PATIENTS AND METHODS
The emergency room of the Habib Bourguiba Hospital, Sfax, Tunisia, manages severe cases of scorpion envenomation, including those of grade II: hyperthermia, shivering, agitation, hypertension, tachycardia, etc.; and the ones of grade III: coma, cardiovascular arrest, etc. (14).Most of these patients are from the southern regions of Tunisia.
A retrospective study about the laboratory data of scorpion-envenomed pregnant patients admitted to Habib Bourguiba Hospital from 1990 to 2004 was carried out.
Twelve pregnant women (7.18%) out of one hundred and sixty-seven scorpionenvenomed patients at reproductive age were evaluated.All patients presented primiparous gestation.
Treatments such as scarification and chlorination, previously administered to the patients, and the implicated scorpion species (unidentified) were ignored in this study.All patients had received a combination of the following treatments: antiscorpion sera, corticoids, phenobarbital, diazepam, hydrocortisone hemisuccinate, salbutamol and oxygenation.The time elapsed between the scorpion sting and the evaluation at the hospital emergency room ranged from 50 minutes to 6 hours and 45 minutes.Variability of the patients' clinical and laboratory profiles according to maternal age, gestational age and number of previous parities was analyzed.Data from eight non-pregnant but envenomed women were randomly chosen to compare clinical and laboratory profiles.Data were analyzed using Anova and Kruskal-Walis tests.

RESULTS AND DISCUSSION
Neither maternal or fetal death, nor preterm fetal delivery was observed among the twelve scorpion-envenomed pregnant patients studied.Ultrasonographic exams revealed no abnormalities either in the fetuses or in the placentas.
The majority of the pregnant patients showed typical symptoms of scorpion envenomation like pronounced hypertension (66.66%), tachycardia (58.33%), agitation (50%) and increased respiratory rate (50%) (Figure 1), which corroborated the observations reported by Ismail (10).Two pregnant patients (16.66%) manifested intense pelvic pain.One of the patients (8.33%), in her second trimester of pregnancy, showed vaginal bleeding after scorpion sting, which disappeared before hospitalization (Table 1).Intense pelvic pain and hypertension were also noticed in pregnant women envenomed by the black widow spider (27,29), and according to Sherman et al. (29), such signs are similar to those observed in preeclampsia.Milson et al. (20) suggested that intense pelvic pain might result from abnormal uterine contractions.Therefore, these symptoms suggested that scorpion venom may lead to abnormal uterine contractions in pregnant women.
Different scorpion species are usually found at Tunisia region.Among the species most frequently involved in severe envenomation cases are Buthus occitanus tunetanus, Androctonus australis and Androctonus aeneas (11).Like other Old-World species, their venoms contain numerous neurotoxins that affect the activity of many ion channels of excitable cells.Such actions may be responsible for the contractions of non-pregnant female uteri (18,19,21,22) induced by the venom of different Old-World scorpion species.Scorpion venom has increased estradiol serum levels (21), and prostaglandin F2 alpha uterine biosynthesis (1) may also increase uterine contraction via its bradykinin-potentiating fraction.Such contractions may have been responsible for the pelvic pain noticed in the present study, although specific tests such as electrophysiological exams were not carried out.
Many factors, such as preterm delivery, perinatal morbidity and mortality (23), have been associated with increased metrorrhagia in the second trimester of gestation.
Vaginal bleeding, probably indicating pregnancy loss, occurred in one out of the twelve cases studied (8.33%).This rate is greater than that of preterm labor in Tunisian pregnant women (10‰ -source not cited).Thus, a venom-induced abortion could be concluded.incl.Trop. Dis., 2007, 13, 1, p. 97 No significant variability of clinical and laboratory profiles according to the studied parameters was found (Table 2).The undefined scorpion species, the patients' body weight, and the individual differences, as well as previous treatments, are important factors implicated in the vulnerability to envenomation (5,12,13).An increase in mean arterial pressure, heart rate, glucose level and number of white blood cells was observed in scorpion-envenomed pregnant women compared with the nonpregnant ones.These signs should be taken into consideration and may require different treatments.
Increased white blood cell count, frequently observed in scorpion-envenomed humans, may increase the serum levels of inflammatory and pre-inflammatory kinins and interleukines (8,9).The levels of such compounds in the maternal organism and placental structures have been strongly correlated with uterine rupture, fetal delivery and placental abruption (25), especially in the case of uterine infections and maternal trauma (28).They have been implicated in the regulation and maintenance of the uterine function during pregnancy and parturition (25,26).Increased white blood cell count may also contribute to the increase of histamine levels, which may modify the contractility of the pregnant myometrium (3).Kubow and Koski (15) reported that altered levels of glucose and fatty acids in the maternal organism may retard the fetuses growth.Also, electrolytic disturbances may result in inadequate maternal-fetal exchange of ions and nutrients through the placenta (4,31).
In the present study, the hospitalization period of one pregnant patient was 15 days and that of other three pregnant patients was 4 days, indicating a chronic effect of the scorpion venom on the victims.Thus, scorpion venom can lead to abnormal inutero fetal development via its action on glucose level (6,10), lipid metabolism (30), and electrolyte balance (2).Scorpion-venom-induced respiratory defect (10) in the maternal organism may contribute to the reduction of the inspired oxygen and thereby to fetal hepatic glucose metabolism disturbances, as reported by Parimi et al. (24).Scorpion envenomation during pregnancy may lead to many biological disturbances influencing the pregnancy process as well as the intrauterine development of the fetus.A systemic experimental study may be helpful to better understand the effects of such envenomation cases, which may influence patient management.Data were expressed as mean ± SD (standard deviation).

Figure 1 -
Figure 1 -Percent of symptoms exhibited by pregnant scorpion envenomed women

Table 1 :
Characterization of pregnant patients envenomed by scorpions.

Table 2 :
Variability of clinical and laboratory parameters of scorpion-envenomed patients according to maternal age, gestational age and number of previous parities, and comparison between pregnant and non-pregnant patients envenomed by scorpions.