What is High Risk Pregnancy?

High risk pregnancy is defined as a pregnancy that has an increased risk of mortality (Death) and/ or morbidity (illness) in the mother and/or fetus (unborn baby), compared to the average mortality/ morbidity of pregnant women in the same environment.

What is Bad Obstetric History?

A woman is said to have a “Bad Obstetric History” if there are disastrous factors related to her previous pregnancies and deliveries.

These factors should be considered in taking decisions about her future management.

What is the difference between high risk pregnancies and bad obstetric history?

In “Bad Obstetric History” there are disastrous factors related to her previous pregnancy/ pregnancy’s and deliveries such as intrauterine death of the fetus, stillbirth, operations etc.

Even a first pregnancy can be a “high risk pregnancy” eg. If there are medical complications such as hypertension and diabetes mellitus in pregnancy.

Therefore it must be emphasized that all patients with “Bad Obstetric History” are high risk patients (but the reverse is not true for all patients).

Factors related to bad obstetric pregnancy

i) Stillbirth:

A detailed history of stillbirth in a previous pregnancy, if present should be taken . Is the stillbirth fresh or marcerated? (Macerated fetus is due to long time spent by the dead fetus in the uterus).

If it is a fresh stillbirth it is important to inquire about the duration of labour, the type of the labour and the mode of delivery.

Proper evaluation should be done of all women who are suspected to have prolonged labour/stillbirth during a previous pregnancy.

Caeserean section should be planned for future pregnancies if there is evidence of contracted pelvis.

Detailed history of the mode of delivery should be taken eg History of difficult forceps may warrant elective caesarian section in future pregnancies.

If the fetus is macerated ,the causes of stillbirth are similar to those described below (Under intrauterine death of the fetus ).

ii) Intrauterine death of the fetus:

Some of the common causes of intrauterine death are essential hypertension, pre eclampsia, chronic nephritis, diabetes mellitus, fetal anomalies,rhesus isoimmunization (Rh- incompatibility), antepartum haemorrhage (Vaginal bleeding during the 2nd and third trimesters of pregnancy) especially accidental haemorrhage, placental insufficiency, maternal syphilis and severe anaemia.

The causes of intrauterine death can be divided into recurrent and non recurrent causes. The recurrent causes will require antenetal supervision and timely delivery.

Placental function tests are also mandatory if there is a previous history of intrauterine death due to recurrent causes, this will enabel better fetal monitoring and determine the optimal time for delivery.

Blood be be transfused promptly if there is recurrent antepartum haemorrhage.

Prevention and treatment of anaemia is also essential in preventing intrauterine death.Recurrent anaemia should be fully investigated.

Maternal syphilis should also be detected early.

ultrasound scanning and measurement of amniotic fluid/serum alpha fetoprotein are very useful in determining abnormal fetuses. They should be carried out especially in women aged 35 years and above.

iii) Operations:

Women who have had two previous cesarean sections should subsequently be delivered by elective cesarean section. This is to avoid the risk of uterine rupture during labour.

A woman who has had a single cesarean section section due to recurrent factor should also be delivered by elective cesarean section.

It is also important to note that women who have had successful repair of vesico-vaginal fistula due to obstetric reasons should be delivered by cesarean section to avoid recurrence.

iv) Neonatal Factors:

Common causes of neonatal death are jaundice and infection. The cause of the neonatal death should be thoroughly investigated and necessary precautions taken.

v) Postpartum factors:

Postpartum haemorrhage(Vaginal bleeding after delivery of the baby) is one of recurrent post partum factors. Morbidly adherent placenta is a cause of recurrent postpartum haemorrhage.

Therefore postpartum haemorrhage should be anticipated in a woman with a previous history of postpartum haemorrhage and adequate precautions taken. This includes getting at least 2 units of blood that is grouped and crossmatched and the administration of 0.5mg of ergometrine intravenously with the delivery of the anterior shoulder.

vi) Puerperium:

Important complications of the puerperium are puerperal psychosis and puerperal sepsis.

Puerperal psychosis in a previous pregnancy can recur in a subsequent pregnancy, therefore a psychiatrist should be consulted.

It is important to know that puerperal sepsis can affect the integrity of a cesarean section scar, which will in turn affect the mode of delivery in subsequent pregnancies.

References:

Textbook of Obstetrics and Gynaecology for Medical Students, Volume II by Akin Agboola et al