Brief Summary

The purpose of this study is to test the application of newly generated placental MRI protocols in human subjects. This new method avoids the need for contrast agent administration and thus provides improved safety for MRI use during pregnancy.

Our objectives are:

1. Establish the normal variance of placental perfusion in pregnant women across gestation.

2. Apply our new MRI protocol in women at high risk for vascular compromise (i.e., smokers and those with a prior history of placental insufficiency) to test the sensitivity and specificity of this new technique for predicting adverse clinical outcomes.

   We hypothesize that, by using non-contrast MRI, we will detect decreased placental perfusion domain function in pregnancies complicated by placental insufficiency.

   Endpoint: Successful development of these tools will significantly advance non-invasive imaging of placental function by creating a method that quantitatively determines placental perfusion while preserving the vascular characteristics that are unique to the human placenta.

Additionally, we are adding an ancillary IUGR arm; the objective of this ancillary arm is to test the sensitivity of the placental MRI protocol in women with confirmed cases of intrauterine growth restriction (IUGR). 

Inclusion Criteria

Chart review to identify potential study participants in early pregnancy to allow the first scan to be scheduled and completed in the 12 – 16 week gestational age range.

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

Ancillary IUGR Arm:  This study arm will comprise 2 groups:

          1) Confirmed cases of IUGR in the current pregnancy

          2) Non-smokers with no complications in their current pregnancy

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

Inclusion criteria for low risk group:

1. Pregnant patient, as defined by positive pregnancy test for elevated β-HCG and certain menstrual history, or early ultrasound, identified prior to 14 weeks of gestation

2. No history of a second or third trimester loss

3. No history of fetal growth restriction

Inclusion criteria for high risk group

1.  Pregnant patient, as defined by positive pregnancy test for elevated β-HCG and certain menstrual history, or early ultrasound, identified prior to 14 weeks of gestation

2. History of pregnancy complicated by placental insufficiency in a previous singleton pregnancy

• Severe preeclampsia requiring preterm delivery
• Preterm delivery due to placental insufficiency (e.g. FGR, oligohydramnios, abnormal umbilical artery Doppler’s, abnormal antenatal testing)
• FGR <10 % delivered at term
• Stillbirth attributed to placental cause, regardless of gestational age

3.  Not currently a smoker

4.  Pregnancy at risk for placental insufficiency due to clinical concerns (e.g., chronic hypertension)

5.  Spontaneous preterm birth <34 weeks

Inclusion criteria for smokers/marijuana group:

1.  Perturbation during current pregnancy 

2.  Pregnant patient, as defined by positive pregnancy test for elevated β-HCG and certain menstrual history, or early ultrasound, identified prior to  14 weeks of gestation

Inclusion criteria for IUGR group and this control sub-group:

1. Intrauterine growth restriction (estimated fetal weight <10^th percentile) confirmed by clinical diagnosis in the current pregnancy.
2. Non-smokers with no complications in their current pregnancy

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 including twin demise regardless of placentation

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 on going treatment:

   • Cancer

   • Active liver disease (acute hepatitis, chronic active hepatitis, persistently abnormal liver enzymes)

   • Chronic pulmonary disease requiring regular use of medication (exercise asthma or seasonal allergies are allowable

6. Prior history of claustrophobia

7. Metal implants. Inclusion of participants with a metal implant will be determined after discussion with each site’s MRI team and will be reviewed on a case-by-case basis, based on type of implant and where the implant is located in the body.

8. Increased aneuploidy risk based on ultrasound findings or genetic testing