Pulmonary embolism (PE) is a Condition where the pulmonary artery is blocked by foreign matter or by a blood clot. It is the leading cause of death among pregnant women in the developed world.
“Women are at an increased risk of both venous and arterial clotting during pregnancy. Compared to women who are not pregnant, the risk of arterial clotting (strokes and heart attacks) is increased 3- to 4-fold and the risk of venous clotting (VTE) is increased 4- to 5-fold. Postpartum, the risk is even higher (20-fold). The overall prevalence of thromboembolic (clot and clot migration) events during pregnancy is approximately 2 per 1000 deliveries. Approximately 20% of these events are arterial, and the other 80% are venous. VTE accounts for 1.1 deaths per 100 000 deliveries, or 10% of all maternal deaths,” said Dr. Sreekanth Shetty, Interventional Cardiologist from Fortis
Hospital, Cunningham Road.
The coexistence of pregnancy makes the workup and management of PE even more problematic. There is similar risk for venous thromboembolism (VTE) in all 3 trimesters of pregnancy, although the incidence of deep venous thrombosis (DVT) is approximately 3 times higher than that of PE during pregnancy.
Pregnancy-associated DVT occurs on the left side of the body in 85% of cases, the likely result of compression of the left iliac vein by the right iliac artery as well as compression by the gravid uterus. Isolated pelvic DVT is much more common in pregnancy or in the early postpartum period than in non pregnant patients, adds Dr. Sreekanth.
The three main risk factors that increase the risk of developing deep vein thrombosis and/or pulmonary embolism are abnormal clotting, reduced blood flow, and damage to the veins. These risks are all higher during pregnancy, most likely because of:
- Changes in hormone levels and blood composition that influence clotting.
- Reduced blood flow in the legs due to the weight of the fetus pressing upon veins.
- Injury to veins during delivery or surgery.
- Inactivity after cesarean section surgery or delivery.
28 year old Ms Hansa (name changed) developed sudden onset of breathlessness and nearly passed out twice. She had been noticing pain and swelling of her right leg since 3 days. When she arrived at Fortis Hospitals, she was diagnosed with Deep vein thrombosis with pulmonary embolism.
She was given a clot buster injection after which she was started on oral blood thinners which she was advised to take for the long term. She had been on Oral contraceptive pills and she has been advised to use other alternative methods of contraception.
The risk of clotting disorders also increases in women on certain oral contraceptives. It is also higher in women receiving hormonal therapies as in post menopausal Hormone Replacement Therapy and Anti-infertility treatments, Dr. Sreekanth told.
VTE risk factors include age greater than 35 years, obesity (body mass index higher than 30 kg per2), grand multiparity, and a personal or family history of VTE or thrombophilia. Bed rest, immobility for four days or longer, hyperemesis, dehydration, medical problems (e.g., severe infection, congestive heart failure, nephrotic syndrome), preeclampsia, severe varicose veins, surgery, and trauma are also associated with an increased risk. Cesarean delivery significantly increases VTE risk compared with vaginal delivery.
Soon after giving birth, the risk of developing deep vein thrombosis or pulmonary embolism rises by 5 times. If a woman has a cesarean section, she is even more likely to develop one or more of these clots. This risk usually returns to normal after a few weeks after delivery.
Mr.and Mrs. Vilas (name changed) had been yearning for a child for almost 15 yrs of their married life but without success. Mrs. Vilas went through multiple attempts of assisted reproduction for which she received hormonal therapy. 6 months ago she was diagnosed to have Deep Vein thrombosis and Varicose veins. She was not on blood thinners. One day she had a sudden onset of severe breathlessness. Therefore she came to Fortis Hospitals where she was diagnosed to have massive pulmonary embolism which was treated appropriately.
“Hormone replacement therapy can improve the quality of life for women with hypo-oestrogenic symptoms. Many women are still prescribed oestrogen therapy to treat postmenopausal symptoms despite recent data showing that overall health risks may exceed benefits of long term hormone replacement therapy. Hormone replacement therapy is also effective for preventing osteoporotic fractures among current users. In contrast, harmful effects of hormone replacement therapy include breast cancer and venous thromboembolism. Furthermore, randomized controlled trials showed that hormone replacement therapy might increase the risk of coronary heart disease and stroke,” Dr. Sreekanth said.