Placental abruption, also known as abruptio placentae, and hypertension in pregnancy, also known as gestational hypertension are two significant problems affecting the health of the mother and the well-being of the developing foetus. Placental abruption occurs when the placenta separates from the uterine wall prematurely before birth, leading to potentially serious complications. Gestational hypertension, which is characterised by high blood pressure during pregnancy, poses risks to both mother and child. 

Placental abruption occurs in approximately 1%  of pregnancies worldwide and 50% of these cases are mild and can be controlled with continued close monitoring of mother and child.  About 25% of cases are moderately severe, and the remaining 25% are life-threatening to the baby and mother.¹

Recognising placental abruption symptoms and managing hypertension disorders through prenatal care is paramount in ensuring a healthy pregnancy outcome. Understanding these conditions is critical for expectant mothers and healthcare providers because early detection and treatment can help mitigate negative consequences.

Classification

Placental abruption can be classified into four classes based on location and extent of separation from the uterus.²

Class 0: asymptomatic 

• Discovered retrospectively after the delivery due to the presence of a retroplacental clot
• Usually associated with partial or marginal separation

Class 1: mild

• Presence of very little or non-existent vaginal bleeding
• Absence of foetal distress
• Mild tenderness over the uterus
• No significant change in maternal blood pressure and heart rate

Class 2: moderate

• Presence of foetal distress
• Increase in maternal heart rate and presence of orthostatic changes in maternal blood pressure
• A moderate amount of vaginal bleeding. However, sometimes bleeding is concealed
• Tenderness over the uterus with tetany
• Usually associated with complete or central placental separation
• Abnormal blood clotting factor changes

Class 3: severe

• Presence of heavy vaginal bleeding (rarely, some cases may present with no sign of bleeding)
• Atonic and tender uterus (hard to touch)
• Foetal distress and death
• Maternal shock and death
• Abnormal blood clotting profile
• Usually associated with complete or central placental separation

Causes and risk factors

In most cases, doctors don't know the exact cause of placental abruption. It is thought that abnormalities in the blood supply to the uterus or placenta may play a role, but the cause of the suspected abnormalities is unclear.² However, there are several factors which may contribute to placental abruption. Known causes and risk factors of placental abruption include:

• Hypertension⁴
• Abdominal trauma
• Higher maternal age (over 35 years)³
• Substance abuse (usually cocaine use during pregnancy)
• Smoking and drinking alcohol
• Prior history of placental abruption
• Twin or multiple gestation pregnancies
• Polyhydramnios
• Preeclampsia
• Sudden uterine decompression (premature rupture of membranes)
• Short umbilical cord

Symptoms

• Vaginal bleeding - Usually the first sign of abruption
• Continuous and persistent abdominal pain
• Tenderness in uterus
• Frequent uterine contractions
• Fetal distress or reduced fetal movement
• Lower back pain 

Sometimes, there is scanty and even non-existent bleeding due to blood being clotted between the placenta and the wall of the uterus. This is also known as a retro placental clot.⁵

Complications of placental abruption⁶

• Maternal haemorrhage leading to shock
• Fetal distress due to lack of oxygen which may lead to brain damage
• Preterm birth
• Stillbirth
• Maternal death in severe cases
• In some cases, emergency hysterectomy is done to prevent further blood loss.
• Recurrence during future pregnancies
• Women with a history of placental abruption have an increased risk of cardiovascular events
• Complications associated with blood transfusion
• Delivery by a caesarean section for present and future possible pregnancies

Diagnosis

The signs and symptoms of placental abruption overlap with other obstetric conditions such as placenta previa, preeclampsia and eclampsia which can sometimes be a contributing factor to the development of placental abruption. Hence, It is important to investigate and rule out other coexisting conditions before it’s too late. The different investigations used to get information for diagnosing placental abruption are as follows:

• Clinical assessment -  includes maternal physical and family history, physical examination to assess the tone and tenderness of the uterus, and internal vaginal and cervix examination using speculum.
• Ultrasound - can be used to check the status of the placenta as well as the foetus.
• Blood pressure monitoring - High blood pressure along with other laboratory results are used to diagnose and differentiate placental abruption from other coexisting conditions.
• Laboratory tests (e.g., urine protein, clotting factors such as PT/APTT) - the presence of a high amount of protein in the urine along with raised maternal blood pressure and other physical symptoms indicate the likelihood of placental abruption in the future.
• Foetal heartbeat monitoring 

In some cases, placental abruption isn’t diagnosed until the delivery due to the presence of an old retroplacental clot. In these cases, the placenta should be sent to the laboratory for further investigations.

Prevention

Placental abruption is life-threatening for both mother and child but there are measures you can take to prevent it. With proper care and advice, it can be avoided. Some of the things a mother can do to prevent placental abruption are as follows: 

• Regular prenatal care and monitoring (especially in cases with a history of previous placental abruption)
• Managing and treating pre-existing hypertension disorders.
• Lifestyle changes (e.g., quitting smoking, avoiding alcohol).
• Prompt treatment of any trauma or injury during pregnancy.
• Avoiding lifting heavy objects, especially during the first trimester (up to 13 weeks)
• Folic acid supplements as prescribed by the doctor
• In cases of substance abuse, drug rehabilitation and drug counselling are proven beneficial⁷

Treatment and management

Abruption of the placenta is an obstetric emergency that is usually catastrophic and requires prompt diagnosis and immediate intervention, usually by emergency cesarean section, to save the foetus and reduce the risk of bleeding complications in the mother. There is no way to reattach the placenta to the wall of the uterus once detached. If left untreated, severe placental abruption can have serious consequences for the mother and her unborn child, including death. However, not all cases need immediate delivery. 

The management of placental abruption depends upon its severity and the condition of the mother and the baby. The gestation age is also taken into consideration when deciding the appropriate approach. 

• Mild cases, during early pregnancy - In these cases, the mother is sent home to rest with medications such as antihypertensives and progesterones after vaginal bleeding is stopped unless the foetus is in distress.⁸ The mother is required to follow up, usually after a week to see the changes.
• Moderate cases, during early pregnancy - The mother is hospitalised for close monitoring and cannot be discharged until the gestational age is old enough to give birth. Sometimes, the doctor may recommend medications that help in the maturing of the foetus’s organs including medications for hypertension.  In most cases, the baby is born pre-term and medication such as surfactant is required to prevent respiratory distress in the newborn.⁹ Oxygen therapy may be required for the baby after birth to prevent foetal distress.
• Mild to moderate cases, during later pregnancy(after 36 weeks) - These require immediate delivery. Depending upon the severity and bleeding, the doctor may choose to deliver vaginally or perform a caesarean section. 
• Severe cases( early pregnancy and after 36 weeks) - In case of severe bleeding and both maternal and fetal distress, the foetus is immediately delivered with caesarean section. The mother needs to be evaluated for shock due to loss of blood and blood transfusion with or without a hysterectomy is warranted. Hospitalisation and supportive care should be given to the mother.

Summary

Placental abruption and hypertension in pregnancy create dangerous conditions for the mother and the developing baby. Approximately 1 per cent of pregnancies globally are affected by placental abruption, whereby the placenta separates prematurely from the uterine wall; this can cause serious complications. On the other hand, gestational hypertension is identified by high blood pressure levels in a pregnant woman, and it leads to risks associated with both the mother's and the fetus's health.

Prenatal care to identify and manage symptoms is also important for a positive outcome in pregnancy. Placental abruption can be classified into four severity classes, where symptoms may range from vaginal bleeding to maternal shock and fetal distress. Risk factors for the condition include hypertension, abdominal trauma, substance abuse, advanced maternal age, and certain pregnancy conditions such as preeclampsia.

The diagnosis of pre-eclampsia and eclampsia can be made by clinical examination, ultrasound, blood pressure measurements, laboratory tests, and auscultation of the fetal heart. Strategies of prevention consist of timely prenatal care, controlling hypertension, making lifestyle changes, and treating traumatic cases.

Depending on the stage of pregnancy and the extent of the condition, treatment can vary. For mild cases, medications along with careful observation are usually advised, whereas, for severe ones, immediate delivery through a cesarean section is essential to prevent complications like maternal bleeding, fetal suffering, premature birth, or even death.

To this end, early identification, appropriate control, and swift treatment are the key factors for a good outcome that would reduce the morbidity of pre-eclampsia and hypertensive disorders in pregnancy, resulting in the optimal health of the mother and baby.