OHSS

1. OVARIAN
HYPERSTIMULATION
SYNDROME
Dr. Satyawan

2. BACKGROUND
• It is a systemic disease resulting from
vasoactive products released by
hyperstimulated ovaries which produce a
hyperpermeability state.
• Totally iatrogenic condition
• Serious and potentially life threatening
• INCIDENCE 0.1 to 6% in pts. Undergoing
COH
• Severe form seen in 0.4% cases.

3. INCIDENCE OF OHSS
1. Mild forms are common effecting 33% of IVF
cycles.
2. Moderate to severe OHSS in 3-8% of IVF cycles.
3. The syndrome can occur after any form of supra-
physiological ovarian stimulation including
clomiphene and gonadotropins stimulation
(Delvigne A. Hum Reprod Update 2002;8:559 – 77)

4. Pathophysiology
• Massive B/L cystic ovarian enlargement
• Significant stromal edema,multiple hgic
follicular & theca lutein cysts,areas of
cortical necrosis & neovascularisation
• Increased capillary permeability leading to
Leakage of fluid from vascular
compartment, third space fluid
accumulation and intravascular
dehydration

5. Mediators of increased capillary
permeability
1. Estrogens
2. Ovarian Renin-Angiotensin system
3. Prostaglandins-?
4. Vasculap Endothelial Growth
Factor
5. Interleukins – IL2,IL6,IL8
6. Angiogenin

6. CLASSIFICATION(Rabau et al,
reorganized by Schenker & Weinstein)
Grade Symptoms
Mild OHSS Abdominal bloating
Mild abdominal pain
supraphysiological levels of E2 &P
Ovarian size usually < 5 cm
Moderate OHSS Moderate abdominal pain
nausea + vomiting
ultrasound evidence of ascites
ovarian size usually 5-12 cm

7. Severe OHSS:
• Clinical ascites (occasionally
hydrothorax/anasarca)
• oliguria
• Creatinine- 1to 1.5 mg%
• Creatinine clearance->= 50ml/min
• Haemoconcentration - haematocrit > 45%
• Hypoproteinaemia
• Ovarian size usually > 12 cm
• Liver dysfunction

8. Critical OHSS :
• Tense ascites or large hydrothorax
• Haematocrit > 55%
• White cell count > 25 000 / ml
• Oligo / anuria
• Creatinine >= 1.6mg%
• Creatinine clearance <= 50ml/min
• Thromboembolism
• Acute respiratory distress syndrome
• Multiorgan failure

9. CLASSIFICATION(Golan &
colleagues)
Mild OHSS:
GRADE I- Abdominal distension and
discomfort
GRADE II- Features of gr 1 plus N,V,D.
Ovaries 5-12 cm

10. Moderate OHSS:
• GRADE III- Features of mild OHSS
plus USG evidence of Ascites

11. SEVERE OHSS:
GRADE IV- ModerateOHSS plus evidence of
ascites and/or hydrothorax and breathing
difficulties
GRADE V- All of above plus change in blood
volume, increased blood viscosity d.t.
hemoconcentration, coagulation
abnormality and diminished renal
perfusion & function.

12. Severe Manifestations
1. Vascular complications:Tendency to develop
thrombosis
2. Renal and liver dysfunction
3. ARDS,pleural effusion causing serious morbidity
and mortality
4. Gastrointestinal complications

13. OHSS is divided into early and late depending on
time of onset.
Early OHSS : OHSS Presenting within 9 days
after ovulatory dose of HCG is likely to reflect
excessive ovarian response and precipitating
defect of exogenous hCG. (Mathur RS. Fertil
Steril 2000;73:901-7)
Late OHSS : Any OHSS presenting after this
period reflects endogenous hCG from early
pregnancy. Late OHSS is likely to be more
serious.

14. RISK FACTORS FOR OHSS
1. Women under 35 yrs of age
2. PCOS patients
3. Asthenic habitus
4. High E2(>4000PG/ML ART, OI>1700)
5. Use of GnRH agonist protocol
6. Development of multiple follicles during
treatment(ART>20, OI>6)
7. Exposure to LH/hCG and
8. Previous episodes of OHSS
9. Pregnancy
Written information about risks and symptoms of
OHSS with a 24 hr contact number of a clinician
should be given.

15. Diagnosis of OHSS
Clinical criteria
History of ovarian stimulation followed by symptoms:
• Abdominal distention ,Abdominal pain
• Nausea/Vomiting
• Respiratory difficulty
• Decreased urine output

16. D/D
• Torsion of ovarian cyst
• Pelvic infection
• Intra-abdominal haemorrhage
• Ectopic pregnancy
• Appendicitis

17. Clinical examination includes
1. Body weight and abdominal girth measurement
2. Pelvic ultrasound to measure ovarian size and check
for ovarian size and ascites.
Laboratory investigations are helpful in assessing
severity of OHSS. These include :
1. Haemoglobin and Haematocrit
2. S. Creatinine and electrolytes
3. Liver function test
.

18. prevention
• Witholding hCG
• Delaying hCG(coasting)
• GnRH agonist to trigger ovulation
• Follicular aspiration
• Luteal phase support with Progesterone
• Cryopreservation of embryos
• Selective oocyte retrieval in spontaneous
conception cycles
• Gradual & slow hMG protocol in PCO
• ALBUMIN at time of OCR
• Glucocorticoid administration

19. OPD MANAGEMENT
Women with mild and many moderate OHSS can be
managed on an OPD basis.
1. Analgesia using paracetamol or codeine is appropriate.
NSAIDS should not be used.
2. Women should be encouraged to drink to thirst rather
than to excess.
3. Strenuous exercise and sexual intercourse should be
avoided for fear of injury or torsion.
4. Women should continue progesterone luteal support
but hCG support is not to be given. Review every 2-3
days is likely to be adequate

20. Urgent clinical review is necessary is
women develops :
1. Increasing severity of pain
2. Increasing abdominal distention
3. Shortness of breath and
4. Decrease in urinary output

21. Inpatient Management
Hospital admission should be recommended to women
with severe OHSS
Women should be kept under review until resolution of
the condition.
Women with moderate OHSS who are unable to
achieve control of pain and / or nausea with oral
treatment should also be admitted.
Multidisciplinary assistance should be sought for all
women with critical or severe OHSS who have
persistent haemoconcentration and dehydration

22. •Features of critical OHSS needs intensive care.
•Doctor experienced in managing OHSS should
remain overall incharge.
•Pain relief with paracetamol and parenteral
opiates. NSAIDS not recommended.
•Antiemetics drugs should be used in possibility
of early pregnancy such as prochlorperazine,
metoclopramide and cyclizine.

23. Inpatient Monitoring of patient with OHSS
Assessment Measurements
History & Examination Pain
Breathlessness
Hydration
Weight
Cardiovascular
Heart rate, blood pressure
Abdominal girth, distention, ascites
Intake and output chart
Investigations Full blood count, Haemoglobin,
haematocrit, white cell count
Urea & electrolytes
Liver function tests
Baseline clotting studies
Pelvic ultrasound (for ascites and ovarian
size)
Chest X-ray or ultrasonography
ECG and echocardiogram

24. Management of fluid balance
Allowing women to drink to thirst represents the most
physiological approach to replacing volume.
Women with severe OHSS with persistent oliguria and
haemoconcentration despite initial colloid volume
expansion may need invasive monitoring and should be
discussed with the anesthetist.
Diuretics should be avoided as they deplete intravascular
volume.
I/V crystalloids such as normal saline should be used.
Most women will need a fluid intake of 2to3 ltrs in 24 hrs
guided by a strict fluid balance chart.

25. Women with haemoconcentration may need
more intensive initial rehydration, such as 1 ltrs
of physiological saline over 1 hr.
Women with persistent haemoconcentration
and/or urine output less than 0.5 ml/kg may
benefit from colloids.
Human albumin, 6% hydroxyethylstarch (HES),
dextran, mannitol and haemaccel have been
used for this purpose.
HES has been reported to be associated with a
higher mean daily urine output, fewer
paracenteses and shorter hospital stay than
human albumin.

26. HES is of non – biological origin and with a
higher molecular weight than human albumin. If
haemoconcentration and / or oliguria persist
despite these measures, paracentesis should be
considered. Further fluid management may be
guided by CVP monitoring.
(Abramov Y, Fertil Steril 1997;71:645-51)
Diuretics may be used where oliguria persists
despite adequate rehydration and usually after
paracentesis.
Role of Dopamine

27. Management of ascites or effusions
Paracentesis should be considered in women who
are distressed due to abdominal distension or in
whom oliguria persists despite adequate volume
replacement. (Levin I, Fertil Steril 2002;77:986-8)
Paracentesis should be performed under
ultrasound guidance to avoid in advertent
puncture of vascular ovaries distended by large
luteal cyst.
Intravenous colloid replacement should be
considered for women who have large volume of
ascitic fluid drained.

28. Management of risk of thrombosis
Thromboprophylaxis should be provided for all women
admitted to hospital with OHSS. This should be
continued until discharge from the hospital and possibly
longer depending on other risk factors. The reported
incidence of thrombosis with OHSS ranges between 0.7 –
10%. (Delvigne A. Hum Reprod Update 2003;9:77-96)
Mechanisms contributing to thrombosis in women with
OHSS include :
1. Hemoconcentration
2. Altered coagulation system and
3. Reduced venous return secondary to enlarged
ovaries
4. Ascites and immobility
(Stewart JA et al. Hum Reprod 1997 ;12:2167 – 73)

29. Full length venous support stocking and
prophylactic heparin therapy may be used.
If thromboembolism is expected, therapeutic
anticoagulation should be started and additional
diagnostic measures such as arterial blood gases
and ventilation/ perfusion scan should be done.

30. Indication of Surgery
Pelvic surgery should be restricted to cases with adenexal
Torsion/rupture of ovarian cysts/ectopic pregnancy or
coincident problems requiring surgery and only
undertaken by experienced surgeon following careful
assessment.
OHSS particularly if associated with pregnancy may be a
risk for ovarian torsion.
(Gorkemli H, et al. Arch Gynecol Obstet 2002; 267 : 4-6)
Torsion should be suspected in presence of :
1. Further ovarian enlargement
2. Worsening of unilateral pain
3. Nausea
4. Leucocytosis and anaemia
5. Colour doppler assessment is helpful

31. OHSS and Pregnancy
Women should be reassured that pregnancy may
continue despite OHSS and there is no evidence
of increased risk of congenital abnormalities.
Severe OHSS is commonly associated with
pregnancy.
High risk of PIH and premature birth in women
with severe OHSS have not been confirmed by
controlled studies.
(Mathur RS et al. BJOG 2000; 107. 943 – 6)

32. THANK YOU