Diagnosing Pregnancy

Pregnancy occurs when an egg fertilized by sperm attaches to the lining of the uterus. It typically lasts 37 to 42 weeks, or about 9 months.

Early symptoms of pregnancy can include breast tenderness or swelling, spotting, cramping, a white milky discharge from the vagina, nausea, fatigue, frequent urination, food cravings or aversions, mood swings, and a missed menstrual cycle. Not all women experience these symptoms.

To determine if you are pregnant, you can use a home pregnancy test, which measures the levels of a pregnancy hormone called human chorionic gonadotropin in the urine. You either hold a test device in your urine stream or dip it into a sample of urine collected in a cup. Tests are available over-the-counter in drugstores, and some can be taken as soon as one day after a missed period.

NYU Langone doctors typically recommend scheduling an appointment for an examination two to four weeks after a missed period. If you have a history of miscarriage or of ectopic pregnancy—in which a fertilized egg implants somewhere other than in the uterus—or if you are experiencing symptoms such as vaginal bleeding or pain, you may require an earlier appointment.

Your NYU Langone doctor tests your urine to confirm that you are pregnant. In addition, he or she performs a physical and pelvic exam to determine your overall health. This includes checking your blood pressure and measuring your weight.

At this visit, your doctor also estimates your due date based on the date of the first day of your last period, if you have regular menstrual cycles. Other methods used to calculate the baby’s due date involve estimating the date of conception or the date of embryo transfer, or measuring the size of the baby during an ultrasound test.

Your doctor asks about your family history and determines your risk factors for complications. These may include prior miscarriage, pregnancy complications such as gestational diabetes and preterm labor, and a family history of congenital heart disease or genetic conditions.

Your doctor discusses any medications you are taking and determines if they are safe to continue taking during pregnancy.

Urine Tests

Your doctor may test your urine for levels of human chorionic gonadotropin to confirm pregnancy. Urine is also tested to determine sugar and protein levels. This helps your doctor to determine if you have diabetes, preeclampsia, or a urinary tract infection.

Blood Tests

Your NYU Langone doctor tests your blood for sexually transmitted diseases, such as syphilis and HIV. He or she also checks your immunity to rubella, which is also called German measles.

Depending on your health and family history, your doctor may check for low levels of thyroid-stimulating hormone, or TSH, which indicate hypothyroidism. Tests can also reveal if you have an inheritable condition, such as sickle cell anemia.

Rh Factor Blood Test

Your doctor determines your blood type and checks your rhesus (Rh) status, which indicates if you have a type of inheritable protein on the surface of red blood cells. If you have the protein, you are considered to be Rh positive; if you lack it, you are referred to as being Rh negative.

If a woman is Rh negative but the baby is Rh positive due to inheriting this protein factor from the father, the woman’s body might produce antibodies if it’s exposed to the baby’s blood. This typically doesn’t affect a first pregnancy, because the baby is often born before the woman’s body develops many antibodies, but it can be a problem in a subsequent pregnancy if the baby is Rh positive.

To prevent potential pregnancy complications like miscarriage, your doctor injects Rh immunoglobulin, a blood product that sensitizes your body to the baby’s blood, before your body has a chance to produce antibodies.