Snake bite in pregnancy: A rare case report

Abstract

INTRODUCTION: Snake bite in pregnancy appears to be uncommon. Only few cases have been reported in the literature. Venomous snake bite in a pregnant woman may lead to poor outcome for both mother and the fetus. Anti-venom causes anaphylactic reactions that may have adverse effects on the mother or fetus. CASE REPORT: A 31-year-old G2P1C1, at 11w 3d of gestation presented one hour following a snake bite on her right foot. On admission, she was conscious and oriented. She was complaining of abdominal pain. Her vital signs were stable. There was an induration and erythema with fang marks on the right foot. Systemic examination was normal. On abdominal examination, there was suprapubic tenderness. Patient was kept under close observation and was investigated with coagulation profile as well as whole blood clotting time (WBCT) test which was repeated six hourly. Ultrasound scan confirmed a viable intrauterine pregnancy. Her third WBCT was delayed with prolonged clotting profile. She was treated with polyvalent antivenomserum (AVS) and was given ICU care. Patient recovered completely. Though she was discharged after three days of hospitalization her pregnancy ended up with miscarriage one week later. DISCUSSION: Snake bite is not common in pregnancy. Studies from Africa, India and Sri Lanka revealed that pregnant women accounted for 0.4% to 1.8% of hospitalized snake bite victims. Snake bite carries significant fetal wastage (43%) and maternal mortality (10%). Snake venom is a complex mixture of enzymes which lead to tissue injury, systemic vascular damage, haemolysis, fibrinolysis and neuromuscular dysfunction culminating in either haematological symptoms or neurological manifestations.The common adverse obstetrical events occurring due to snakebite are miscarriage, IUD, and premature labour. Mechanisms which causes fetal death are; fetal anoxia associated with maternal shock after envenomation, abruptio placentae, premature uterine contractions initiated by venom, pyrexia and cytokines released after tissue damage, maternal haemorrhage leading to acute fetal anaemia, supine hypotension syndrome and anaphylaxis to AVS.Anti-venomserum can cause anaphylactic reactions which may have an adverse effect on the mother or fetus. Though the fetal death rates up to 55% to 85% has been reported in mothers given AVS, most authors have recommended anti-venom administration for snake bite during pregnancy. While the safety of anti-venom is unclear in pregnancy, the risks of withholding, likely outweigh the risks of administrating in needy patients.