Author Information
Durga Valvi*, Parulekar SV**,
Karnik ND***, Samant PY****
(* Assistant
Professor, ** Professor and Head of Department, **** Additional Professor
Department of Obstetrics and Gynecology, *** Professor, Department of Medicine.
Seth GS Medical College and KEM Hospital , Mumbai ,
India
Abstract
Snake bite
envenomation is uncommon during pregnancy. Severity of obstetric consequences
depends on the degree of envenomation. We report a case of G2P1L1 with 36 weeks
of pregnancy who presented with history of snake bite. The patient developed severe coagulopathy and
neuroparesis. The patient recovered
after successful treatment with antivenom, antibiotics and transfusion of blood
products.
Introduction
In studies
from South Africa , India , and Sri Lanka
Case Report
A
patient G2P1L1 with 36 weeks of pregnancy presented with snake bite on right
index finger in her village. The patient had swelling and severe pain at site
of bite, weakness in all limbs proximally, bodyache, and giddiness. She
received 10 vials of polyvalent antivenom at a peripheral medical facility and
was transferred to our hospital.
On
physical examination, the patient was conscious, oriented, and hemodynamically
stable. Power of all four limbs was grade-4, knee jerks were brisk and plantar
reflexes were extensor. On abdominal examination her uterus was 32 weeks’ size
and relaxed, and fetal heart sounds were normal and regular. On vaginal
examination the cervix was uneffaced and the os was closed. On local
examination there was a blister at bite mark and bluish black discoloration of
hand.
Figure
1. Site of snake bite on the right index finger.
On
admission laboratory investigations were: Hemoglobin 11.6 g/dL, White blood
count 32,000/cmm, Platelets 0.24 million/ml, Clotting time more than 20 min,
INR was 1.25, Liver and Renal function tests were normal. The patient was admitted in intensive care unit
and started on antivenom injections and antibiotics. On the second day her clotting time was
increased to more than 1 hour and INR was more than 10. The Patient
received 6 units of fresh frozen plasma and 2 units of
cryoprecipitate. Antivenom was continued
in a dose of 5 vials twice daily for next 3 days. She needed 2 units of fresh frozen
plasma daily for next 5 days to maintain PT/INR and clotting within normal limits. The
patient went into labor on day 3. Nifedepine was administered in a dose of 10
mg PO q6h for tocolysis in view of severe
coagulopathy. Both clotting time and INR
were decreased to normal level by day 5. Fetal non stress test was reactive.
Routine obstetric scan was normal. The patient's neuromuscular weakness recovered totally by day 5. She was
discharged on day 9. Two weeks later patient was delivered 2.7 kg alive female
baby vaginally. The postpartum period was uneventful.
Discussion
Snakebite in pregnancy is a
rare event and seems to be related to the fact that pregnant women are
homebound, avoiding outdoor activities. The
obstetrics consequences are severe and related to severity of the
envenomation. The common adverse
obstetrical events in snake bite cases are antepartum hemorrhage, abruption of
the placenta, postpartum hemorrhage, premature labor, decreased fetal
movements, and intrauterine fetal death. Snake venom is a mixture of complex
biochemical compounds inducing potentially uterotonic substances that may have direct effect on
uterine muscle or act indirectly by releasing or potentiating effect of
bradykinin which causes preterm labor.[7,8]
Nifedepine
can be given for tocolysis in snake bite patient but magnesium sulfate is
contraindicated in neurotoxic snake envenomation. Our patient had severe
coagulopathy hence Nifedepine was started to delay labor to avoid potential
massive intrapartum and postpartum hemorrhage.
The
adverse obstetrical events may occur because of the following pathophysiology.
- Direct effect of venom on the fetus
- Fetal hypoxia due to maternal shock
- Venom induced uterine contractions
- Placental bleeding due to coagulopathy[7]
Early
gestational age at the time of snakebite and
delay in treatment may result in an unfavorable prognosis for pregnancy
due to a slight decrease of platelets in early pregnancy.[6] The effect of antivenom on the fetus remains
unclear but anaphylactic reactions caused by antivenom may have an adverse effect on the mother or
fetus.[1]
The venom can cause systemic poisoning in the
fetus even without evidence of
envenomation in the mother.[5]
Incoagulable
blood suggest viper bite and rules out elapid bite. In our case, the exact
identity of snake could not be ascertained but neurotoxicity associated with severe coagulopathy was
suggestive of Russel Viper bite. Neurotoxic symtoms in Russel Viper are
believed to be due to presence of presynaptic toxin.
Neostigmine
is an anticholinesterase used in neurotoxic snake bite but it is effective
against post synaptic toxins such as those of cobra and there is some doubt
against presynaptic toxins. Neostigmine is a category C drug. It could cause
preterm labor if given intravenously, but potential benefits may warrant use of
the drug in pregnancy despite potential risk.[9] Our patient
responded to antivenom and blood component replacement therapy. She did not need Neostigmine as her
neuromuscular paralysis was mild and responded to above treatment itself.
References
1.
Seneviratne SL, de Silva CE, Fonseka M,
Pathmeswaran A,Gunatilake SB, de Silva HJ. Envenoming due to snake during
pregnancy. Trans R Soc Trop,Med Hyg. 2002;96:272-274.
2.
Gold B, Dart R, Barish R.Bites of venomous snakes.
N Eng J Med. 2002;345: 347-356.
3.
David P.Principal actions of venoms and their
symtoms. In: Bauchot R, ed. Snakes: A Natural History.New York: Sterling
Publishing Co ; 2006: pp 208-209.
4.
Dunnihoo DR,
Rush BM, Wise RB, Brooks GG, Otterson WN. Snake bite poisoning in
pregnancy.A review of the literature. J Reprod Med 1992 ;37(7):653-8.
5. Mcnally
SL., Reitz CJ. Victims of snakebite. A
5-years study at Shongwe
Hospital
6. Rezende J. Obstetricia. 4.ed. Rio de Janeiro:
Guanabara Koogan, 1987: 649-63.
7.
Habib AJ, Abubaker
SB, Doufa S, Noabi A, Yusuf PO. Envenoming after Carpet Viper bite during
Pregnancy. Timely
use of asv Improves maternal and fetal outcomes; Tropical Med Int Health.
2008;13: 1172-1175.
8.
Langley RL. A Review of venomous animal
bites and stings in pregnant patient; Wilderness and Environmental
medicine.2004; 15: 207-215.
9.
Neostigmine Pregnancy and Breastfeeding
Warnings. Available at: http://www.drugs.com/pregnancy/neostigmine.html
Citation