Placenta Previa

The cervical encirclage operation given among the options, is mostly effective for cervical incompetence which usually occurs around 14 weeks of pregnancy.

It has no proven significant role in the treatment of placenta previa which occurs after the 28th week of pregnancy.

While the other three options are included in the treatment of placenta previa.

Ref: Dutta 6th edition Page 171 & Page 243; Obstetrics and Gynecology By Charles R. B. Beckmann, American College of Obstetricians and Gynecologists, Barbara M. Barzansky, Frank W. Ling, Douglas W. Laube, Page 208-209, Page 128

Browne’s classification for placenta previa:

The initial hemorrhage in placenta previa is usually painless and rarely fatal.

If the fetus is premature and if hemorrhaging is not severe, vaginal examination of a woman suspected of having placenta previa frequently can be delayed until 37 weeks gestation; this delay in the potentially hazardous examination reduces the risk of prematurity, which is often associated with placenta previa.

Vaginal examination, when needed to determine whether a low- lying placenta is covering the internal os of the cervix, should be performed in an operating room fully prepared for an emergency cesarean section.

Increasing maternal age and multiparity are associated with a higher incidence of placenta previa. 

• Total placenta previa—the internal os is covered completely by placenta
• Partial placenta previa—the internal os is partially covered by placenta
• Marginal placenta previa—the edge of the placenta is at the margin of the internal os
• Low-lying placenta—the placenta is implanted in the lower uterine segment such that the placental edge does not reach the internal os, but is in close proximity to it

A patient with 37 weeks of pregnancy and severe degree of placenta previa with bleeding per vagina, the next step of management should be immediate C.S.

Per vaginal examination if unavoidable should only be performed in an operation theatre when the patient has already got bleeding per vagina, is at term and immediate termination of pregnancy is about to be done.

Expectant management of placenta praevia by Macafee and Johnson method:

• It is an attempt to improve the fetal salvage without increasing undue maternal hazards.
• The aim is to continue pregnancy for fetal maturity without compromising the maternal health.
• Suitable cases: Mother is in good health status, duration of pregnancy is less than 37 weeks, active vaginal bleeding is absent, and fetal well being is assured.

Ref: Textbook of Obstetrics by D.C. Dutta, 6th edition, Page 251.

Ans. is d i.e. Present after first trimester

Blood turns yellow° (i.e. hemoglobin is denatured) Blood remains pink° (hemoglobin intact)

Maternal origin                      Fetal origin°

Antepartum hemorrhage is defined as bleeding from or into the genital tract after the 28M week of pregnancy but before the birth of the baby ( the first and second stage of labour included). The 28th week is taken arbitrarily as the lower limit of fetal viability.

Associated with toxemia

Conservative treatment

Active labour

a and b both`

Trans vaginal sonography

Ans. is c i.e Primigravida                             

Placenta previa is implantation of the placenta partially or completely over the lower uterine segment. Damage to the endometrium or myometrium due to previous surgery or infection can predispose to low implantation and placenta previa.

Risk factors for placenta previa :

• Prior surgery° (cesarean section / Myomectomy Hysterotomy)
• Previous uterine curettage°
• Endometritis°
• Increasing maternal age (>35 years)°
• Increasing parity°
• Placental sire –increased (as in multiple pregnancy)
• Placental abnormality –Succenturiate lobe
• Smoking (due to defective decidual vascularisation)

Note :

• The probability of placenta accreta and need for cesarean hysterectomy is increased in patients with prior cesarean section and placenta previa.
• Smoking increases the risk of placenta previa by two fold times.
• Previous cesarean section increases the risk of placenta previa by 4 fold time.
• According to the latest edition of Williams—Women with otherwise unexplained elevated screening level of maternal serum alpha feto protein are at a greater risk of placenta previa.

Ans. is a i.e. Incidence increaes by two fold after LSCS Ref. Fernando Arias 3/e, p 333-334; Dutta Obs. 6/e, p 243-244

Chances of placenta previa are increased in case of history of prior cesarean section

“The probability of placenta previa is four times greater in patients with prior cesareans than in patients without uterine scars.”                                                                                       
Therefore, option a is correct (partly though) because the option says two-fold increase As far as – other options are concerned

Option ‘b’ i.e. it is more common in primipara is absolutely wrong as – placenta previa is more common in multipara.

Option ‘c’ It is more common in developed countries.

Now that is incorrect because ‑

“Increased family planning acceptance with limitation and spacing of birth, lowers the incidence of placenta previa.”

Ans. is c i.e. Hemodynamically unstable condition

The aim of expectant management in case of placenta previa is to continue pregnancy for fetal maturity without compromising the maternal health.

Prerequisites for expectant management

• Availability of blood for transfusion whenever required
• Facilities for cesarean section should be available throughout 24 hours.

Candidates : Suitable for expectant management are :

• Mother in good health status — Hemoglobin > 10 gm%

— Hematocrit > 30%

• Duration of pregnancy less than 37 weeks
• Active vaginal bleeding is absent
• Fetal well being is assured by USG and cardiotocography.

The expectant management is carried upto 37 weeks of pregnancy until baby matures,

Indications for active treatment I contraindications for putting the patient to expectant management.

• Bleeding occurs at or after 37 weeks
• Patient is in Tabour-‘
• Patient is in exsanguinated state on admission
• Bleeding is continuing and is of moderate degree
• Baby is dead or known to be congenitally deformed
• Severe degree of bleeding
• Fetal distress.”

Coming to option “c”i.e. hemodynamic unstable condition of mother — Hemodynamic unstable condition means there is a change in vital signs of the patient due to blood loss and approximate blood loss is 15-30% of the blood volume (Moderate blood loss).

Remember :

Mild bleeding

blood loss <15%

No charge in vital signs/ urinary output

Moderate bleeding

blood loss between 15-30%

Pulse rate ‘I/ B/P / cold clammy extremities

Severe bleeding

blood loss >30%

Patient in shock with decreased or unrecordable BP, Oliguria or anuria

So initial hemodynamic instability is not a contraindication for expectant management but if the condition remains unstable for 24 – 48 hours despite resuscitative measures, it is a contraindication for expectant management.

Note: Since in this question there is no other correct option, therefore, we are saying hemodynamic unstability of mother is not a contraindication for conservative management and finding out ways to support it but if there was a better option then I would have included hemodynamic unstability in the contraindication for conservative management

Ans. is a, b  and c i.e. Active labour; Anencephaly; Dead baby; and Severe placenta previa

Well friends, there is no need to “rattoo” the conditions where expectant management is required and where active management. For a while – forget all the lists and just think you are a gynae casualty medical officer and a pregnant female with vaginal bleeding in the late months of pregnancy comes to you (suspected case of

placenta previa). How will you manage if :

If fetus is dead

Ans. is a, b and c i.e. Active bleeding, Active labour and Fetal malformation

Ans. is B. i.e. Bed rest, Nifedipine and Dexamethasone

The given situation is a case of preterm labor.

Management of Preterm Labor at < 34 Weeks

• Corticosteroids (Betamethasone/Dexamethasone)

                             +

• Short term tocolytic (Best-nifedipine)

                              +

• MgSo4 (for neuroprotection in pregnancy)

Cesarean section

Central placenta praevia

Ans. B i.e. Type IV placenta previa

Caesarean section

Indications of classical caesarean section

• Previous classical cesarean section
• Neglected shoulder with anhydramnios
• Structural abnormality making approach to lower segment difficult
• Constriction ring due to neglected labor
• Fibroids in lower segment
• Anterior placenta accreta and praevia
• Very preterm fetus, where lower segment is poorly formed.