Placenta Imaging Project

The purpose of this study is to test the application of newly generated magnetic resonance imaging (MRI) protocols for the assessment of placental perfusion in human subjects. The primary objective is to validate and establish the utility of placental MRI in pregnant women. The study will be entirely MRI-technology based with collection of placental tissue at the time of infant delivery for later correlative studies.

The placenta provides all the nutrition from a pregnant mother to a developing fetus. A placenta that functions normally is needed to ensure normal fetal growth and development. Unfortunately, the placenta is the least understood human organ even though it is involved in all pregnancy complications. The placenta is so poorly understood because our current methods to look at it during pregnancy, like ultrasound, do not provide enough information about placental growth and function.

This study will help provide information about:

* How the placenta grows and develops during pregnancy
* How the placenta delivers nutrients, like oxygen to the developing fetus
* If placental function using new advanced imaging tools can predict pregnancy complications like fetal growth restriction, stillbirth, preeclampsia and preterm labor

This study will explore how blood flow to the placenta affects placental growth, fetal growth, and oxygen delivery to the fetus. Blood flow to the placenta may determine how the placenta supports fetal growth and development. Having a way to measure placental function during pregnancy may provide a way to understand normal pregnancies but importantly also identify pregnancies at increased risk for pregnancy complications.

Additionally we want to have an ancillary intrauterine growth restriction (IUGR) arm; the objective of this ancillary study is to test the sensitivity of the placental MRI protocol in women with confirmed cases of IUGR in the third trimester.

Eligibility Criteria:
Pregnant women will be recruited based on inclusion criteria for 3 subject groups:

1. Non-smokers with low risk for placental insufficiency
2. Smokers
3. Non-smokers who are at a high risk for adverse outcomes based on prior clinical history.

Inclusion criteria: Pregnant women fulfilling inclusion criteria, and not meeting exclusion criteria, will be invited to participate in this study.

Inclusion criteria for all groups:

1. Maternal age over 18 years and able to give informed consent
2. Pregnant patient, as defined by positive pregnancy test for elevated β-human chorionic gonadotropin (HCG) and certain menstrual history, or early ultrasound, identified prior to 14 weeks of gestation

Inclusion criteria for low risk group:

1. No history of a second or third trimester loss
2. No history of fetal growth restriction

Inclusion criteria for high risk group:

1. History of pregnancy complicated by placental insufficiency in a previous singleton pregnancy (i.e. severe preeclampsia requiring preterm delivery, preterm delivery due to placenta insufficiency (eg. fetal growth restriction (FGR), oligohydramnios, abnormal umbilical artery Doppler's, abnormal antenatal testing), FGR \<10% delivered at term; stillbirth attributed to placental cause, regardless of gestational age
2. Not currently a smoker
3. Pregnancy at risk for placental insufficiency due to clinical concerns (eg. chronic hypertension)
4. Spontaneous preterm birth \<34 weeks

Exclusion criteria: These criteria will exclude women whose medications, personality traits or obstetric conditions could confound their ability to complete a 1 hour MRI scan.

1. Individuals with intellectual disability or who are incarcerated
2. Multiple gestation
3. Major fetal anomalies known to be associated with abnormal growth (i.e. major congenital heart defect, gastroschisis)
4. Current maternal history of alcohol or illicit drug use
5. Current medical problems requiring chronic treatment:

   * Cancer
   * Active liver disease (acute hepatitis, chronic active hepatitis, persistently abnormal liver enzymes)
   * Chronic pulmonary disease including asthma requiring regular use of medication
6. Prior history of claustrophobia
7. Metal implants
8. Increased aneuploidy risk based on ultrasound findings or genetic testing