Pregnancy Guide

Woman in hospital bed holding swaddled baby.


Congratulations on your pregnancy! This is a time of big change for you and your loved ones, and we are committed to helping you make your pregnancy and birth experience happy and healthy.

At the Center for Women’s Health, a comprehensive team of providers are here to guide you. Whether everything goes smoothly, or you or your baby have special needs, we offer skilled physicians, perinatologists, nurse-midwives, nurses, and support staff.

We also offer many services often not found in other practices, including physical therapy, nutrition, mental health, naturopathy, acupuncture and social work.

What to expect

As a patient seeing an OB-GYN, your primary maternity provider is an M.D. who will see you for most of your prenatal care visits. You may also see one of our team’s midwives or advanced practitioners for some prenatal care visits. If your pregnancy becomes high risk, we may refer you to a perinatologist (maternal fetal medicine specialist) or seek their advice.

At the hospital for delivery, you will be cared for by our team of physicians, including both residents and faculty.

To reach us:

To speak to a nurse, schedule an appointment or address urgent needs during business hours, please call 503-418-4500.

When the clinic is closed, please send us a MyChart message. We will respond within three business days.

For emergencies when the clinic is closed, call 503-494-8311 and ask to speak to the OB-GYN provider on call. Please call if you experience any of the following:

  • Unable to keep down fluids for more than eight hours
  • Vaginal bleeding
  • Severe cramping or pain
  • Fever over 100.4 F (or 38 C)

As a midwifery patient, you can see any member of our midwifery team during your prenatal visits. We recommend that you establish care with one or two midwives for the majority of your prenatal care. We have found that patients appreciate having consistent care providers throughout pregnancy.

In addition to one-on-one care, we offer a group prenatal care option. This is a great way to get to know other parents due when you are and to spend more time with our midwives discussing pregnancy, what to expect during labor, and more.

OHSU’s nurse-midwives offer waterbirth. Learn more about laboring in water and waterbirth by watching our videos.

To reach us:

To speak to a nurse, schedule an appointment or address urgent needs during business hours, please call 503-418-4500.

When the clinic is closed, please send us a MyChart message. We will respond within three business days.

For emergencies when the clinic is closed, call 503-494-8311 and ask to speak to the midwife on call. Please call if you experience any of the following:

  • Unable to keep down fluids for more than eight hours
  • Vaginal bleeding
  • Severe cramping or pain
  • Fever over 100.4 F (or 38 C)

Pregnancy resources from midwives:

Prenatal Screening and Diagnosis

Prenatal screening and diagnosis helps provide information about the health of an unborn baby.

Screening tests provide information about the risk of certain genetic abnormalities. These are non-invasive, so they pose no risk of miscarriage or complication to your pregnancy. However, these tests cannot tell for certain whether a developing baby is healthy. They are used to measure whether there is a high or low chance of abnormalities. Examples of screening tests are the sequential screen and the cell-free DNA test.

Diagnostic tests are the most accurate tests for detecting chromosomal abnormalities and specific genetic diseases. However, they are invasive, which means they may involve a risk of miscarriage or other complications. They are typically offered to women at higher risk, but are available to all women. Examples of diagnostic tests are amniocentesis and CVS (chorionic villus sampling).

Prenatal Screening and Diagnosis booklet
Español: Pruebas de detección y diagnóstico prenatal

From ACOG:
Routine Tests During Pregnancy
Genetic Disorders FAQ
Reducing Risks of Birth Defects

From ACNM:
Making Decisions about Prenatal Tests for Birth Defects

Anatomic abnormalities can be found by ultrasound. Most pregnant women have an anatomic screening ultrasound at 20 weeks.

An ultrasound uses sound waves to look at your baby. Most major birth defects are found by ultrasound during the second trimester, but ultrasound cannot find all birth defects. Some types of ultrasound available are:

  • Nuchal Translucency (NT) measurement
    The NT is a normal fluid-filled space at the back of the baby’s neck. Sometimes babies with chromosome abnormalities or heart defects have extra fluid in this space. Performed early in your pregnancy (11.5 to 13.5 weeks).
  • “Anatomy” or “Level II” ultrasound
    This ultrasound looks at your baby’s growth and anatomy, such as the heart and brain. Sometimes a minor change in the baby’s body will be found that alters the risk of chromosome problems and further tests may be offered. Performed in the second trimester (20 to 22 weeks).
  • Fetal echocardiogram
    This specialized ultrasound looks more closely at the baby’s heart. It is usually performed by a pediatric cardiologist and is recommended for women with a higher chance of having a baby with a heart defect.

Genetic abnormalities can be found through blood sample screening. These screening use the pregnant parent’s blood.

  • Cell-free DNA screening
    This blood test indicates if a woman is at increased risk of having a baby with certain chromosome abnormalities. It is most accurate for people at higher-risk of having abnormality, such as those over age 35. Performed any time after 10 weeks of pregnancy. Detection rates:
    • Down syndrome: 98-99%
    • Trisomy 18: 95%
    • Trisomy 13: 90%
    • Rate of false positive or test failure: 3-5%
  • Sequential screen
    This test combines information from two blood tests (one in the first trimester, one in the second) with NT measurements. This can tell if you have a higher or lower chance of having a baby with Down syndrome, trisomy 18 or open spina bifida. The detection rate for Down syndrome is 90% and the false positive rate is up to 5%.
  • Quadruple marker screening (Quad screen)
    This blood test can tell if you have a higher or lower chance of having a baby with Down syndrome, trisomy 18 or spina bifida. The detection rate for these conditions is 80% and the false positive rate is 5%. Performed at 16 to 20 weeks.

From ACOG:
Prenatal Genetic Screening Tests FAQ

  • Down syndrome (Trisomy 21)
    Individuals with Down syndrome have a wide spectrum of abilities and disabilities. They have learning difficulties, some more serious than others. Health problems such as heart defects and hearing or vision concerns are linked with Down syndrome. Down syndrome is caused by an extra chromosome 21. It is not usually passed down in families and the odds of having a baby with Down syndrome increase with a mother’s age.
  • Trisomy 18 and Trisomy 13
    These conditions are caused by an extra chromosome. Many pregnancies with either condition end in miscarriage and most babies born with Trisomy 18 or 13 die shortly after birth. Some children with these conditions may live longer, but they have complicated medical problems and are severely mentally disabled. The odds of these conditions increase with a mother’s age.
  • Sex chromosome conditions
    Usually, females have two copies of the X chromosome and males have one X and one Y chromosome. Any variation in the number of sex chromosomes causes a genetic condition. In some cases, these conditions lead to developmental delay and a variety of psychological, physical or growth differences. Some sex chromosomal abnormalities have little impact and can go undetected.
  • Spina Bifida
    This birth defect is an opening along part of the baby’s spine. Babies with spina bifida often need surgery after birth. Some children with spina bifida have physical or intellectual disabilities. The chance of having a baby with spina bifida does not increase with age, but women with diabetes or other medical complications may be at higher risk.

Recessive conditions are inherited genetic diseases that can happen even in families with no previous history of the disease. Certain recessive conditions are more common in specific ethnic populations.

Carrier screening involves a blood test for one or both partners. Regardless of your family history, we will offer you carrier screening for cystic fibrosis and spinal muscular atrophy, and screening for blood disorders. A genetic counselor can review your family history and geographic ancestry and may offer other tests.

  • Cystic fibrosis: 1 in 25 people with Northern European ancestry are carriers.
  • Spinal muscular atrophy: approximately 1 in 50 people are carriers
  • Sickle cell disease and other blood disorders: more common in those with African, Southeast Asian, Middle Eastern, Mediterranean or West Indian descent
  • Fragile X syndrome: recommended if you have a family history of either this disorder or intellectual disability suggestive of this disorder, or if you have a personal history of ovarian insufficiency
  • Tay Sachs disease: one of many conditions more common in those with Ashkenazi Jewish ancestry

Expanded carrier screening panels
These tests can screen for multiple conditions, including those above. It may be useful for couples before pregnancy who are considering in vitro fertilization, but can be performed during pregnancy as well for either partner.

Chorionic villus sampling
Chorionic villus sampling (CVS) is usually done from 11 to 14 weeks of pregnancy. A thin plastic tube is inserted through the cervix or a needle is inserted through the abdomen to take cells from the placenta. Ultrasound is used as a guide during the test. The risk of serious complication is about 0.5%.

Amniocentesis uses a thin needle to remove about two to three tablespoons of the amniotic fluid surrounding the developing baby. This is usually done from 16 to 22 weeks, but can be done later in special circumstances. The risk of serious complication is less than 0.5%.

From ACOG: Prenatal Genetic Diagnostic Tests

A genetic counselor is a health care worker who is specially trained to discuss the possibility of a genetic disease or birth defect in your family. Their job is to explain the benefits and risks of screening and diagnostic testing, and to help you make an appropriate decision. You can meet with a genetic counselor anytime to discuss the many testing options, even if you are not at high risk for these problems.

Learn more: Genetic Counseling

Pregnancy Resources

One of your most important missions during your pregnancy is good nutrition. What you eat now impacts your baby’s health throughout their life. Here are some food tips for a healthy pregnancy:

  • You only need about 300 extra calories per day
  • Avoid fast food, processed snacks, fried foods
  • Avoid food that is more likely to make you sick, including packaged lunchmeat, undercooked or raw meat, seafood and eggs, unpasteurized dairy products, and anything you suspect may have spoiled
  • Wash fruits and vegetables well before eating, cutting or cooking
  • Avoid fish with high levels of mercury (like swordfish, king mackerel, tilefish or shark)
  • Choose small whole-food snacks, such as fresh fruit, vegetables, nuts, or peanut butter on whole-grain toast
  • Limit your caffeine to one cup of coffee or two cups of tea per day (no more than 200 mg of caffeine)
  • Avoid artificial sweeteners
  • Drink eight to 10 glasses of fluid per day, including water, milk and soup
  • If you are a vegetarian or have other dietary restrictions, please ask about meeting with our dietitians to make a nutrition plan.

These tips may help if you experience nausea or vomiting during pregnancy:

  • Eat before you feel hungry
  • Drink before you start eating
  • Eat what you can, when you can
  • Try ginger root in your food or tea
  • Use a nausea relief wrist band, such as Sea-band
  • Brush your teeth
  • Go outside for fresh air and avoid stuffy rooms
  • Don’t take vitamins or supplements on an empty stomach
  • Avoid odors or foods that trigger your nausea
  • Take 25mg of vitamin B6 three times per day, and ½ tablet of Unisom (doxylamine succinate) at bedtime
  • From ACOG: Morning Sickness
  • From ACNM: Nausea and Vomiting During Pregnancy

More resources:
My Pregnancy Plate | Spanish
Diabetes and Pregnancy: My Pregnancy Plate | Spanish

From the FDA: Advice about Eating Fish | Spanish
From ACOG: Nutrition During Pregnancy | Spanish
From ACOG: Gestational Diabetes
From ACOG: Obesity and Pregnancy
From ACNM: Women of Size and Pregnancy
From ACNM: Weight Gain During Pregnancy

Keep up your regular exercise routine, even if you have to take it easy more than usual. You will probably need to decrease intensity and may become out of breath more quickly. If you don’t exercise regularly, it’s a great time to start! We recommend moderate intensity exercise for 30 minutes most days of the week. Some great options include: a brisk walk, hiking, stationary bike, elliptical, prenatal yoga, swimming.

Avoid these kinds of exercise:

  • Extreme exertion at high altitude
  • Contact sports (ice hockey, soccer, basketball)
  • Potential for falls (horseback riding, downhill skiing, road biking)
  • Scuba diving

From ACOG: Exercise During Pregnancy
From ACNM: Exercise in Pregnancy

Our mental health and wellness team provides care for women who are pregnant or post partum. Our clinicians are uniquely qualified to understand and support you through the subtle and important ways that pregnancy and parenthood impact your mental health.

Substance Use

For the health and safety of you and your baby, we recommend you avoid smoking, drinking and drug use during pregnancy. There is no known safe amount of alcohol or marijuana during pregnancy. If you smoke, drink or use drugs, we can connect you with resources to help you quit.

From ACOG:
Marijuana and Pregnancy
Opioid Use Disorder and Pregnancy

Medications, Herbal Remedies, Supplements

Some medications, including vitamin supplements, over-the-counter medications, and herbal remedies, can be harmful to a developing baby. Talk to your provider before using any medications.

Do not stop taking prescription medication, however, until you have talked with your health care provider. Although some medications may increase the risk of birth defects, the benefits of continuing to take the medication during pregnancy may outweigh the risks to your baby.

Use acetaminophen (Tylenol) to relieve minor problems, such as a mild headache or backache or a mild fever with cold symptoms. Do not use nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) or naproxen (Aleve), unless your provider says it is okay.

From ACNM: Taking Medicine During Pregnancy

For more information on exposures to avoid during pregnancy, including household items, chemicals, pets, infections, and more, check out Mother to Baby or call them toll-free at 866-626-6847 to talk with an expert.

If you are interested in acupuncture during your pregnancy, we have an in-house expert. Learn more about acupuncture at the Center for Women's Health.

Are there other topics or resources you need more information about? Ask your provider for more information, and as topics arise we’ll add them to this guide.

From ACOG: Travel During Pregnancy
From ACOG: A Partner’s Guide to Pregnancy
From ACNM: Sex During Pregnancy


Unfortunately, miscarriages are very common. Approximately 20% of pregnancies end in miscarriage. However, another 20% of healthy pregnancies have bleeding in early pregnancy. Not all uterine cramping or vaginal bleeding results in miscarriage. The occasional cramp in your uterus is probably not an indication of a miscarriage. However, if you experience continuous cramping or have any bleeding, please let your provider know.

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Pregnancy Research

Research and clinical trials at OHSU help lead to new discoveries and treatments every day. Check out our currently enrolling studies related to pregnancy.