Circumvallate placenta

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Circumvallate Placenta
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The thickened ring of membranes on the fetal surface of a circumvallate placenta, making it appear as though the central part of the placenta has been exposed.
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Circumvallate placenta is a rare condition affecting about 1-2% of pregnancies, in which the amnion and chorion fetal membranes essentially "double back" on the fetal side around the edges of the placenta. [1] After delivery, a circumvallate placenta has a thick ring of membranes on its fetal surface. [2] Circumvallate placenta is a placental morphological abnormality associated with increased fetal morbidity and mortality due to the restricted availability of nutrients and oxygen to the developing fetus.

Contents

Physicians may be able to detect a circumvallate placenta during pregnancy by using an ultrasound. However, in other cases, a circumvallate placenta is not identified until delivery of the baby. Circumvallate placenta can increase the risk of associated complications such as preterm delivery and placental abruption. Occasionally, a circumvallate placenta can also increase the risk of neonatal death and emergency caesarean section. Although there is no existing treatment for circumvallate placenta, physicians can attempt to minimize the effects of complications, if they occur, through frequent fetal monitoring and, if necessary, emergency cesarean section. [1]

In a circumvallate placenta, the chorionic plate, which forms the fetal surface of the placenta, tends to be smaller than the basal plate, which forms the maternal surface of the placenta. This results in the elevation of the placental margin and the appearance of an annular shape. [3] The fetal surface is divided into a central depressed zone surrounded by a thickened white ring which is incomplete. The ring is situated at varying distances from the margin, or edges, of the placenta. This thick ring of membranes is composed of a double fold of amnion and chorion with degenerated decidua vera and fibrin in between. Blood vessels, supplying nutrients and carrying waste products to and from the developing fetus, radiate from the umbilical cord insertion to as far as the ring of membranes, and then disappears from view. [4]

Signs & Symptoms

A circumvallate placenta does not always induce associated symptoms during pregnancy, making it extremely difficult to diagnose a circumvallate placenta in asymptomatic mothers. In symptomatic mothers, physicians may be able to detect a circumvallate placenta based on the presentation of the following signs. [1]

Complications

Circumvallate placenta has also been associated with a higher incidence of complications including placental abruption, low birth weight, premature delivery, perinatal death, and fetal abnormalities.

Cause

Unfortunately, there is no known cause of circumvallate placenta and no major preventative measures that can be taken to minimize the risk of developing a circumvallate placenta. [1] Circumvallate placenta is not a genetic disorder. Some potential causes of circumvallate placenta include reduced amniotic fluid pressure, circumferential hemorrhage, and superficial or deep implantation of the embryo within the uterine wall, although these potential causes are still not well-understood in terms of their relation to circumvallate placenta. [4]

High-risk pregnancies are described as pregnancies in which a mother, the fetus, or both are put at a higher risk for developing pregnancy complications before, during, or after birth. Risk factors such as hypertensive medical conditions, maternal age, and substance use are just some of the things that can put a woman at an increased risk for developing circumvallate placenta and/or any other complications. [5]

Risk factors

Hypertensive disorders

Women entering a pregnancy with hypertension are considered to be put at a higher risk for preeclampsia or eclampsia during the course of their pregnancy. Hypertensive disorders, like hypertension, have been found to affect about 10% of pregnancies in the United States and have resulted in about 6.8% of maternal deaths from 2011 to 2015. High blood pressure during pregnancy can potentially damage maternal organ systems such as the liver or the kidneys, which can be life-threatening. To prevent preeclampsia or eclampsia from developing in pregnancy, women with hypertension can be prescribed anti-hypertensive medications during pregnancy and are advised to monitor their blood pressure throughout the course of pregnancy. [5]

Maternal age

Another risk factor for developing any pregnancy complications is maternal age. Advanced maternal age, considered to be when a woman enters pregnancy at age 35 or above, has also been linked to increased risk of maternal mortality, preeclampsia, restricted fetal growth, fetal distress, and a variety of other pregnancy complications. Conversely, teenage pregnancy is also associated with increased risk of endometriosis, postpartum hemorrhage, and mild preeclampsia, when compared with pregnant mothers in their 20s. [5] Genetically, the long period of time between meiotic arrest of the egg gamete as a fetus and each ovulation cycle occurring after the onset of female puberty in teenage years can potentially contribute to the increased risk for pregnancy complications in mothers who are age 35 or older at time of pregnancy. [6]

Substance use

Further, yet another factor inducing adverse complications in pregnancy is substance use status. Nicotine, alcohol, and marijuana are the most common substances used during pregnancies. Substance use in pregnancy is concerning because of its alarming association with other risk factors, such as mental illness. Depression alone has been associated within increased risk for preeclampsia, gestational diabetes, hypertension, premature birth, and low birth weight. Women with substance use disorders tend to live in areas that are unable to provide quality prenatal care or proper management of their psychiatric conditions. As a result of improper management of psychiatric illnesses, substances are abused during pregnancy, potentially causing harm to both the mother and the fetus. Some pregnancy complications that can occur as a result of substance use in pregnancy are fetal alcohol syndrome and neonatal abstinence disorder. [5]

Women with these risk factors are recommended additional surveillance during pregnancy to monitor fetal development and to be able to detect fetal, placental, or umbilical cord abnormalities as early as possible.

Pathophysiology/Mechanism

The placenta is a transient organ developed during pregnancy that facilitates nutrient, gas, and waste exchange between a mother and a developing fetus. Placental abnormalities, such as circumvallate placenta, can harm a developing fetus, as normal exchange of materials between a mother and a developing fetus is impaired. With placental abnormalities, a developing fetus is unable to receive the vital materials that it needs for proper development, resulting in the possibility of pregnancy complications, birth defects, and/or death of the fetus.

In a normal placenta, there is a smooth transition from the parenchymal villous chorion to the membranous chorion at the border of the placental plate. Fetal blood vessels subdivide from the umbilical cord and spread diagonally throughout the parenchyma towards the edge of the placental plate. [4]

In a circumvallate placenta, the membranes often become restrained due to marginal infarct, hemorrhage, or fibrin depositing. This results in the reduction in size of the chorionic plate of the placenta, further causing the membranes on the fetal side to fold backward on themselves.[ medical citation needed ] The parenchymal villous chorion continues to proliferate beyond the tethered membranes and appears to protrude outward. The fetal blood vessels are directed downward and then horizontally in order to provide blood flow to the most peripheral parts of the placental plate extending beyond the tethered membranes. [4]

Since a portion of the placenta tends to become exposed in a circumvallate placenta, due to the reduced size of the chorionic plate, vaginal bleeding is more likely to occur at this site of exposure. Likewise, inhibited fetal growth can also ensue due to the decreased exchange of nutrients and waste between mother and fetus, since the fetus is unable to sustain necessary nutritional demands for proper fetal development. Premature rupture of membranes often occurs as a result of infection in the uterus, which can be caused by the occurrence vaginal bleeding. Therefore, placental abnormalities such as circumvallate placenta can be extremely detrimental in causing the onset of associated conditions.

Diagnosis

In some cases, a physician may be able to diagnose a circumvallate placenta via ultrasound during one of many routine ultrasound screenings. In most cases, a circumvallate placenta is not discovered until physical examination of the placenta after delivery of the fetus. [1] For this reason, circumvallate placenta is very difficult to diagnose during pregnancy.

On ultrasound, a normal placenta should appear complete and uniform, with the fetal surface of the placenta appearing slightly shiny and translucent. The appearance of a circumvallate placenta on ultrasound may present with irregular edges, uplifted margins, or placental sheets. In a study conducted in 1994, 62 healthy pregnant women were examined with placental sonography for detection of circumvallate placenta. Of the five experienced sonologists who interpreted the placental ultrasounds, all were unable to properly detect and diagnose circumvallate placenta, revealing the difficult nature of circumvallate placenta recognition. [4] Further, these findings indicate that prenatal sonographic criteria used for detection of circumvallate placenta are not reliable enough for screening purposes.

Complete circumvallate placenta involves morphological abnormality of the entire dimension of the placenta, while partial circumvallate placenta does not involve the entire placenta but rather a portion of the placenta. [4] Complete circumvallate placenta is very rare, occurring within about 1% of pregnancies, and has been noted to increase the risks of associated complications such as placental abruption, premature childbirth, premature rupture of membranes, perinatal death, and congenital abnormalities. [1] Partial circumvallate placenta is more common but is not found to be as clinically significant as complete circumvallate placenta. [4]

The accurate diagnosis of circumvallate placenta during pregnancy can have significant implications in the recognition of patients who are at risk of complications. Although the ability of sonography to accurately diagnosis circumvallate placenta during pregnancy is quite limited, research studies continue to emerge at the possibility of doing so.

Treatment/Management

Although there is no cure or specific treatment for restoration of the circumvallate placenta, there are ways to decrease the risks of possible complications prior to birth or attempt to manage complications if they develop. If circumvallate placenta is diagnosed during pregnancy, physicians may offer recommendations to reduce the risks of associated complications such as lower birth weight and placental abruption. [1]

Decreased birth weight is a major concern associated with circumvallate placenta. Infants born with birth weights that are lower than expected per their gestational age oftentimes end up requiring extra support in the neonatal intensive care unit (NICU). To assist in the monitoring of appropriate fetal growth, a physician may recommend more frequent growth checks during pregnancy if circumvallate placenta is suspected. If a fetus is not growing satisfactorily, premature delivery, via vaginal delivery or caesarean section, may be recommended, with C-section being more favorable compared to vaginal delivery. [1]

In women experiencing a placental abruption associated with circumvallate placenta, physicians will normally advocate for frequent growth checks, hospital bed rest, early delivery, and, if necessary, emergency C-section. [1] Likewise, IV fluids and blood transfusions can also be given to patients with a placental abruption in attempts to increase blood pressure and minimize the effects of severe blood loss.

If oligohydramnios occurs as a result of a circumvallate placenta, a treatment called amnioinfusion may be considered to replenish the amount of lost amniotic fluid within the amniotic sac. Amnioinfusion may help in preventing underdevelopment of the lungs.

If diagnosed with a circumvallate placenta, consistent fetal monitoring by a licensed physician can help to prevent and/or reduce the effects of associated complications that may occur. Additionally, healthy lifestyle choices, a well-balanced and nutritious diet, adequate rest, and cessation of alcohol and tobacco products can also help to prevent the incidence of a circumvallate placenta and its associated complications.[ medical citation needed ] If diagnosed with a circumvallate placenta, in association with other threatening pregnancies complications, emergency cesarean section will most likely be suggested by a physician. [3]

Prognosis

Unfortunately, there is currently not a cure available for circumvallate placenta. While some evidence suggests that a circumvallate placenta can increase the risk of complication during pregnancy, other research suggests this increased risk is marginal. Sadly, circumvallate placenta can occasionally result in infant death depending on the severity of the complications encountered. In other cases, circumvallate placenta can result in premature birth of infants who are otherwise healthy after being monitored in the neonatal intensive care unit for a period of time after birth. Therefore, proper medical care and monitoring are crucial in attempting to minimize the likelihood of complications. [1] In other cases, patients diagnosed with circumvallate placenta are able to carry their babies until term or near-term.

Epidemiology

Circumvallate placenta is a very rare condition affecting pregnant women. This condition is a placental morphological abnormality, with the placenta being formed during the early periods of pregnancy. Women are able to become pregnant with the onset of ovulation and menstruation in early adolescence, with most women becoming pregnant during adulthood. Circumvallate placenta is currently known to affect about 1-2% of pregnancies. It is not virally transmissible to other individuals, nor can it be transferred through contact or respiration. [1]

There are no specific racial or ethnic groups that are more predisposed to acquiring a circumvallate placenta during pregnancy, however, as with all pregnancies, there are general risks factors that can put a pregnant woman at risk for complications, including circumvallate placenta. Notably, certain pregnancy complications, such as preeclampsia, tend to be almost three times as fatal in African American women compared to non-Hispanic white women, even though both groups tend to experience preeclampsia at almost the same rates. This is partially thought to be due to inequalities in accessing quality prenatal care in lower socioeconomic neighborhoods and the effect of structural racism within healthcare systems. [5] Any woman residing in an area with a lower socioeconomic status, regardless of race or age, is predisposed to developing pregnancy complications like circumvallate placenta if quality prenatal care is not available.

Women with significant obstetric histories can also be at higher risk for developing any type of pregnancy complication, including circumvallate placenta, and are recommended to be screened for placental abnormalities within their second trimester of pregnancy. [3]

Research

The placenta plays a dominant role in being responsible for a variety of complications within pregnancy and labor. Placental pathological studies have significantly contributed to recent obstetric literature. Many studies have examined the clinical significance of patients with circumvallate placenta compared to patients with a normal placenta. They have revealed that incidences of preterm birth, oligohydramnios, placental abruption, low birth weight, and fetal death were present in significantly higher rates than when compared to control patients with normal placentas.

A case study reported in 2020 observed the correlation between circumvallate placenta and the occurrence of obstetric complications such as battledore insertion. Battledore insertion, abnormal insertion of the umbilical cord into the placenta, occurs in about 7% of pregnancies and can also result in many of the same pregnancy complications as circumvallate placenta; intrauterine growth restriction, fetal distress, and fetal death. This abnormal insertion of the umbilical cord into the placenta can result in a loss of adequate blood flow to the developing fetus due to restriction. [3] The fetus is unable to obtain normal amounts of required oxygen and nutrition through the placenta, and this can further cause other severe complications.

In the study, a 22-year-old woman at 28 weeks and 2 days of gestation, presented for a routine third trimester screening. She was noted to have had 2 prior miscarriages at 17 and 20 weeks. A previous normal second trimester routine screening at 21 weeks of gestation did not identify any structural abnormalities within the placenta, decreased fetal size, or abnormally-appearing umbilical cord insertion. The patient also did not have any episodes of vaginal bleeding during the current pregnancy. [3]

Upon presenting for routine screening at 28 weeks and 2 days of gestation, the patient was not exhibiting any signs of active contractions and a cardiotocography was performed as part of routine screening. [3] Cardiotocography is a diagnostic tool used during the third trimester of pregnancy to observe fetal heart rates and presence of uterine contractions. It can also be used to detect signs of any sort of fetal distress. [7] In interpreting the cardiotocography that the 22-year-old pregnant woman had completed, it was noted that the fetus appeared to be much smaller than expected and was exhibiting concerns of decreased amniotic fluid volume, oligohydramnios, and restricted blood flow through the umbilical cord. Cardiotocographic monitoring also noted decreases in fetal heart rate every 25 minutes without contractions. Fetal motion was present, with the placenta appearing enlarged and spherical. [3]

Decreases in the fetus' heart rate, in addition to the other findings of the cardiotocography, ultimately prompted physicians to deliver the baby via emergency cesarean section without major complications. The newborn, with normal APGAR scores and umbilical cord arterial pH levels, was admitted to the neonatal intensive care unit. Upon examining the placenta after delivery, it was noted that the placenta demonstrated the appearance of a circumvallate placenta, and also showed evidence of abnormal umbilical cord insertion into the placenta. Postpartum, the mother had a good recovery and the newborn was discharged from the neonatal intensive care unit 105 days post-birth. [3]

This case study discussed the association of circumvallate placenta and abnormal battledore cord insertion in producing pregnancy complications. Restriction of umbilical cord blood flow from the placenta to the fetus and placental abnormalities like circumvallate placenta may work in conjunction to generate fetal distress. Decreased levels of oxygenation and nutrient absorption resulted in decelerations of fetal heart rate and the decision to deliver the fetus via cesarean section to prevent fetal death by hypoxia. Routine monitoring of fetal growth and development, placental structure, and placental function are recommended with high-risk pregnancies. In patients diagnosed with circumvallate placenta during pregnancy, monthly fetal growth assessments are also recommended. Patients found to have blood flow restrictions to or from the placenta are recommended to undergo weekly ultrasounds with consistent monitoring of fetal heart rate. [3]

In a separate case study reported in 2017, a woman at about 35 weeks of gestation presented with preeclampsia and intrauterine fetal demise, or more commonly known as stillbirth. After delivery of the stillborn fetus, examination of the placenta revealed a circumvallate placenta with battledore insertion of the umbilical cord. It was speculated that the combination of circumvallate placenta and battledore insertion had led to the loss of the fetus prior to delivery, as there was no other discernible cause for the stillbirth. While circumvallate placenta and battledore insertion are individually very rare conditions that can result in multiple pregnancy complications, the coexistence of these abnormalities likely resulted in the loss of the fetus. [8] The diminished blood flow and circulation from the placenta to the fetus, as caused by battledore insertion, in combination with the impaired exchange of nutrients and wastes between mother and fetus, as caused by circumvallate placenta, likely contributed to the preeclampsia and this loss of fetal life.

Thus, it is highly recommended that if placental or umbilical cord abnormalities, such as circumvallate placental and battledore insertion, are suspected or detected prior to birth, that the pregnancy should be considered high-risk. High-risk pregnancies significantly benefit from frequent follow-ups using ultrasonography to monitor fetal developmental and placental and umbilical cord structure and function. [8]

Research directions continue to investigate methods in which circumvallate placenta may be more commonly diagnosed during pregnancy before complications can transpire. Biomarkers such as Sflt/PlGF can be used to predict severe pregnancy complications in high-risk pregnancies. Circumvallate placenta appears to be correlated with reduced placental efficacy due to increased placental thickness and abnormal villi function, affecting the Sflt/PlGF ratio. It is thought that obtaining Sflt/PlGF ratios can be used to determine deficiencies in placental function in cases of placental abnormalities. [3] Future research analyzing the contribution of biomarkers like Sflt/PlGF to predict placental abnormalities would be influential to our understanding of many placental deformities, including circumvallate placenta. [3]

Due to the rare occurrences of circumvallate placenta, more extensive research trials are unavailable, resulting in data limitations. Therefore, the clinical importance of circumvallate placenta remains uncertain. [3]

Related Research Articles

Obstetrics is the field of study concentrated on pregnancy, childbirth and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology (OB/GYN), which is a surgical field.

<span class="mw-page-title-main">Amniocentesis</span> Sampling of amniotic fluid done mainly to detect fetal chromosomal abnormalities

Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is necessary to conclusively diagnose the majority of genetic disorders, with amniocentesis being the gold-standard procedure after 15 weeks' gestation.

Fetal distress, also known as non-reassuring fetal status, is a condition during pregnancy or labor in which the fetus shows signs of inadequate oxygenation. Due to its imprecision, the term "fetal distress" has fallen out of use in American obstetrics. The term "non-reassuring fetal status" has largely replaced it. It is characterized by changes in fetal movement, growth, heart rate, and presence of meconium stained fluid.

Oligohydramnios is a medical condition in pregnancy characterized by a deficiency of amniotic fluid, the fluid that surrounds the fetus in the abdomen, in the amniotic sac. It is typically diagnosed by ultrasound when the amniotic fluid index (AFI) measures less than 5 cm or when the single deepest pocket (SDP) of amniotic fluid measures less than 2 cm. Amniotic fluid is necessary to allow for normal fetal movement, lung development, and cushioning from uterine compression. Low amniotic fluid can be attributed to a maternal, fetal, placental or idiopathic cause and can result in poor fetal outcomes including death. The prognosis of the fetus is dependent on the etiology, gestational age at diagnosis, and the severity of the oligohydramnios.

<span class="mw-page-title-main">Twin-to-twin transfusion syndrome</span> Medical condition

Twin-to-twin transfusion syndrome (TTTS), also known as feto-fetal transfusion syndrome (FFTS), twin oligohydramnios-polyhydramnios sequence (TOPS) and stuck twin syndrome, is a complication of monochorionic multiple pregnancies in which there is disproportionate blood supply between the fetuses. This leads to unequal levels of amniotic fluid between each fetus and usually leads to death of the undersupplied twin and, without treatment, usually death or a range of birth defects or disabilities for a surviving twin, such as underdeveloped, damaged or missing limbs, digits or organs, especially cerebral palsy.

Rupture of membranes (ROM) or amniorrhexis is a term used during pregnancy to describe a rupture of the amniotic sac. Normally, it occurs spontaneously at full term either during or at the beginning of labor. Rupture of the membranes is known colloquially as "breaking the water" or as one's "water breaking". A premature rupture of membranes (PROM) is a rupture of the amnion that occurs at full term and prior to the onset of labor. In cases of PROM, options include expectant management without intervention, or interventions such as oxytocin or other methods of labor induction, and both are usually accompanied by close monitoring of maternal and fetal health. Preterm premature rupture of membranes (PPROM) is when water breaks both before the onset of labor and before the pregnancy's 37 week gestation. In the United States, more than 120,000 pregnancies per year are affected by a premature rupture of membranes, which is the cause of about one third of preterm deliveries.

<span class="mw-page-title-main">Placental abruption</span> Medical condition

Placental abruption is when the placenta separates early from the uterus, in other words separates before childbirth. It occurs most commonly around 25 weeks of pregnancy. Symptoms may include vaginal bleeding, lower abdominal pain, and dangerously low blood pressure. Complications for the mother can include disseminated intravascular coagulopathy and kidney failure. Complications for the baby can include fetal distress, low birthweight, preterm delivery, and stillbirth.

Antepartum bleeding, also known as antepartum haemorrhage (APH) or prepartum hemorrhage, is genital bleeding during pregnancy after the 28th week of pregnancy up to delivery.

Bloody show or show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It is caused by thinning and dilation of the cervix, leading to detachment of the cervical mucus plug that seals the cervix during pregnancy and tearing of small cervical blood vessels, and is one of the signs that labor may be imminent. The bloody show may be expelled from the vagina in pieces or altogether and often appears as a jelly-like piece of mucus stained with blood. Although the bloody show may be alarming at first, it is not a concern of patient health after 37 weeks gestation.

Obstetrical bleeding is bleeding in pregnancy that occurs before, during, or after childbirth. Bleeding before childbirth is that which occurs after 24 weeks of pregnancy. Bleeding may be vaginal or less commonly into the abdominal cavity. Bleeding which occurs before 24 weeks is known as early pregnancy bleeding.

<span class="mw-page-title-main">Prelabor rupture of membranes</span> Medical condition

Prelabor rupture of membranes (PROM), previously known as premature rupture of membranes, is breakage of the amniotic sac before the onset of labor. Women usually experience a painless gush or a steady leakage of fluid from the vagina. Complications in the baby may include premature birth, cord compression, and infection. Complications in the mother may include placental abruption and postpartum endometritis.

<span class="mw-page-title-main">Complications of pregnancy</span> Medical condition

Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.

Postterm pregnancy is when a woman has not yet delivered her baby after 42 weeks of gestation, two weeks beyond the typical 40-week duration of pregnancy. Postmature births carry risks for both the mother and the baby, including fetal malnutrition, meconium aspiration syndrome, and stillbirths. After the 42nd week of gestation, the placenta, which supplies the baby with nutrients and oxygen from the mother, starts aging and will eventually fail. Postterm pregnancy is a reason to induce labor.

<span class="mw-page-title-main">Vasa praevia</span> Condition in which fetal blood vessels cross or run near the internal opening of the uterus.

Vasa praevia is a condition in which fetal blood vessels cross or run near the internal opening of the uterus. These vessels are at risk of rupture when the supporting membranes rupture, as they are unsupported by the umbilical cord or placental tissue.

<span class="mw-page-title-main">Percutaneous umbilical cord blood sampling</span>

Percutaneous umbilical cord blood sampling (PUBS), also called cordocentesis, fetal blood sampling, or umbilical vein sampling is a diagnostic genetic test that examines blood from the fetal umbilical cord to detect fetal abnormalities. Fetal and maternal blood supply are typically connected in utero with one vein and two arteries to the fetus. The umbilical vein is responsible for delivering oxygen rich blood to the fetus from the mother; the umbilical arteries are responsible for removing oxygen poor blood from the fetus. This allows for the fetus’ tissues to properly perfuse. PUBS provides a means of rapid chromosome analysis and is useful when information cannot be obtained through amniocentesis, chorionic villus sampling, or ultrasound ; this test carries a significant risk of complication and is typically reserved for pregnancies determined to be at high risk for genetic defect. It has been used with mothers with immune thrombocytopenic purpura.

<span class="mw-page-title-main">Velamentous cord insertion</span> Velamentous placenta

Velamentous cord insertion is a complication of pregnancy where the umbilical cord is inserted in the fetal membranes. It is a major cause of antepartum hemorrhage that leads to loss of fetal blood and associated with high perinatal mortality. In normal pregnancies, the umbilical cord inserts into the middle of the placental mass and is completely encased by the amniotic sac. The vessels are hence normally protected by Wharton's jelly, which prevents rupture during pregnancy and labor. In velamentous cord insertion, the vessels of the umbilical cord are improperly inserted in the chorioamniotic membrane, and hence the vessels traverse between the amnion and the chorion towards the placenta. Without Wharton's jelly protecting the vessels, the exposed vessels are susceptible to compression and rupture.

An obstetric labor complication is a difficulty or abnormality that arises during the process of labor or delivery.

<span class="mw-page-title-main">Emergency childbirth</span>

Emergency childbirth is the precipitous birth of an infant in an unexpected setting. In planned childbirth, mothers choose the location and obstetric team ahead of time. Options range from delivering at home, at a hospital, a medical facility or a birthing center. Sometimes, birth can occur on the way to these facilities, without a healthcare team. The rates of unplanned childbirth are low. If the birth is imminent, emergency measures may be needed. Emergency services can be contacted for help in some countries.

The anomaly scan, also sometimes called the anatomy scan, 20-week ultrasound, or level 2 ultrasound, evaluates anatomic structures of the fetus, placenta, and maternal pelvic organs. This scan is an important and common component of routine prenatal care. The function of the ultrasound is to measure the fetus so that growth abnormalities can be recognized quickly later in pregnancy, to assess for congenital malformations and multiple pregnancies, and to plan method of delivery.

References

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