Participants will understand how to care for pregnant women with placental complications.
After completing this continuing education course, the participant will be able to:
The placenta develops along with the fetus at the time of fertilization. The placenta provides oxygen and nutrients to the fetus while removing waste from the fetus as well. The placenta is usually attached to the top, side, front or back of the uterus, but can also attach lower, which may lead to complications.
There are factors that can place the placenta at risk for complications. Some placental complications are more common in women over 40. Issues that can impact placental function and can lead to placental complications include1:
Abnormal development is the first set of complications with the placenta. Preeclampsia and intrauterine fetal growth restriction may be caused by abnormal development of the placenta. When defects in endovascular extravillous trophoblast (EVT) invasion occur, some spiral arteries are not invaded at all, and some are invaded superficially. This can lead to reduced blood flow in the intervillous space and hypoxia.2
The placenta accreta spectrum is a group of placental abnormalities based on adherence of the placenta, including placenta accreta, increta, and percreta.2 Placenta accreta is defined as abnormal trophoblast invasion of part or all of the placenta into the myometrium of the uterine wall.3 Placenta accreta is when the placental villi attach to the myometrium. In placenta increta, the villi penetrate into the myometrium and in placenta percreta, the villi penetrate through the myometrium to the uterine serosa or other organs.4 The chief risk factors for placenta accreta spectrum are previous c-sections, previous placenta previa, or previous uterine surgery.3
Placenta accreta spectrum is often diagnosed with ultrasound. An MRI may be used to evaluate the placenta further, but MRI has not been proven to improve the accuracy of diagnosis.
Women with placenta accreta spectrum should deliver in an experienced, high-level of maternity care center with a multi-disciplinary team.5 This team should minimally include experienced obstetricians, maternal-fetal medicine specialists, pelvic surgeons, urologists, interventional radiologists, anesthesiologists, critical care experts, general surgeons, and neonatologists.3 These women should usually deliver between 34 0/7 – 35 6/7 weeks gestation. Earlier delivery may be recommended. Before the woman delivers, she should have pre-op consultations with appropriate providers and have her hemoglobin maximized. All team members should be aware of the time of scheduled c-section. During surgery, cell saver should be used, and blood products should be available. Postoperative care may require intensive care.3
Women with placenta accreta spectrum are at high risk for hemorrhage. A hysterectomy may be necessary to stop hemorrhage during delivery. These women may also have an injury to other organs and require extensive surgery. The fetus is at risk for preterm delivery.
Placenta previa is when the placenta extends over the cervical os. The main risk factors for placenta previa are a previous previa, previous c-sections, or a multiple gestation. Placenta previa is diagnosed by ultrasound. The woman may present with vaginal bleeding. A vaginal exam should not be performed on a pregnant woman who is bleeding. An ultrasound should be performed.6
Placenta previa puts a woman at high risk of antepartum and postpartum hemorrhage. Women with previa are advised not to have sexual intercourse or perform heavy lifting or exercise, as this may increase their risk of bleeding. Actively bleeding placenta previa is an obstetric emergency. These women should be stabilized if possible and may need a blood transfusion. A woman may not have to deliver at the first sign of bleeding if she stabilizes. Women with uncomplicated placenta previa should have a c-section at 36 0/7 – 37 6/7 weeks. If the bleeding is severe and persistent, delivery may be indicated at any gestational age. The fetus is at risk for preterm delivery.7
Placental abruption is complete or partial detachment of the placenta before delivery of the fetus. The main findings with placental abruption are bleeding, abdominal pain, and hypertonic uterine contractions. Uterine tenderness and an abnormal fetal heart tracing are also usually seen with placental abruption. A rupture of maternal vessels is the usual cause of abruption, although rarely the bleeding starts with fetal vessels. Low pressure hemorrhage generally occurs at the periphery of the placenta, is called marginal abruption, and can be self-limiting and stabilize. Lighter vaginal bleeding is seen with this type of abruption. A chronic abruption is chronic, light, intermittent bleeding, that can lead to fetal growth restriction or oligohydramnios. High pressure hemorrhage generally causes complete or nearly complete separation of the placenta, which can be life-threatening to the mother and fetus.8
A previous abruption increased the risk of abruption with each pregnancy. Cocaine, smoking, and hypertension are all risk factors for placental abruption.
Placental abruption can cause maternal hemorrhage, disseminated intravascular coagulation (DIC), shock, and death for the mother. The fetus is at risk of fetal growth restriction, preterm delivery, low birth weight, and hypoxemia and asphyxia, which can lead to death.9 A woman who is stable with a reassuring fetal status may wait for delivery until after 36 weeks and may deliver vaginally. Women who are unstable need to delivery emergently by c-section.8
All placental complications can be dangerous for the mother or fetus. It is important that the nurse understands the risks and treatments for each problem. All of these women need close monitoring of maternal and fetal status. If a nurse is caring for a woman with placenta accreta syndrome, the nurse should be part of any interdisciplinary care planning. This nurse needs to know that hemorrhage is a serious possibility. Labor and delivery nurses may provide long-term care for a woman with a previa that is hospitalized for antepartum bleeding. Any nurse caring for a severe abruption has to be ready for an emergent c-section and the possibility of a massive hemorrhage.
It is also important that the nurse remembers the emotional component of caring for these women. Often, the care given may be emergent and focused on saving the mother and fetus. This can be overwhelming to the woman and her family. It is imperative to explain what is happening to the woman and her family. The experience can be traumatic to everyone involved.
R.S. is a 22-year-old woman who has had 3 babies, all delivered by c-section. She does not have custody of these children because of her history of drug abuse. She is currently 32 weeks pregnant. She has had limited prenatal care. She smokes and admits to using cocaine earlier in pregnancy and several times over the last month, including earlier today. She arrives at your labor and delivery complaining of active, severe, bright red vaginal bleeding and abdominal pain of 10/10. Her BP is 100/60, HR 135, temp 98.6, resp 20, and pulse ox 95%. Her cervix is 2cm dilated and 20% effaced. When you put her on the monitor, the fetal heart tracing shows a category 3 tracing with absent variability and recurrent, late decelerations. What do you think is happening? What are the priorities for this woman?