Most pregnancies progress without intervention, but if you’ve experienced a loss before or feel anxious about keeping this one, there are concrete steps that improve your chances. About 27% of women experience some bleeding or spotting in the first trimester, and the majority of those pregnancies continue normally. Understanding what actually matters, from nutrition and monitoring to medical support, can help you focus on what’s in your control.
Why Some Pregnancies Don’t Continue
The most common cause of early pregnancy loss is a chromosomal abnormality in the embryo. This is largely random and not something you caused or could have prevented. Other factors that increase risk include uncontrolled chronic conditions like diabetes or thyroid disease, structural issues with the uterus, blood-clotting disorders, and hormonal imbalances, particularly low progesterone.
If you’ve had two or more losses, your doctor can run tests to look for treatable causes. These include blood-clotting conditions like antiphospholipid syndrome, uterine abnormalities, hormonal levels, and genetic factors in both partners. Knowing the cause changes the plan significantly.
Progesterone and Other Medical Support
Progesterone is the hormone that sustains the uterine lining and supports early pregnancy. For women with a history of miscarriage or who experience vaginal bleeding in the first trimester, supplemental progesterone can make a difference. In a large clinical trial (the PRISM trial), women received vaginal progesterone pessaries twice daily, starting as soon as an intrauterine pregnancy was confirmed and continuing through 16 weeks. The benefit was most pronounced in women who had experienced previous losses.
If you have antiphospholipid syndrome, a condition where the immune system creates blood clots that can block blood flow to the placenta, the standard approach is low-dose aspirin started before conception, with a blood thinner added once pregnancy is confirmed. This combination dramatically improves pregnancy outcomes for women with this diagnosis.
For women at high risk of preeclampsia (due to chronic high blood pressure, kidney disease, diabetes, or a previous preeclampsia diagnosis), the U.S. Preventive Services Task Force recommends 81 mg of aspirin daily starting after 12 weeks of gestation. Your provider will assess whether you fall into this category based on your medical history.
Cervical Insufficiency
Some women lose pregnancies in the second trimester because the cervix opens too early, without contractions or pain. This is called cervical insufficiency, and it’s typically diagnosed based on a history of painless cervical dilation before 24 weeks or through ultrasound monitoring that shows the cervix shortening. If identified, a cerclage (a stitch placed around the cervix to keep it closed) can be done to support the pregnancy through to viability. Women with a known history of cervical insufficiency are usually monitored with regular ultrasounds starting around 16 weeks.
What to Eat and What to Avoid
Start taking at least 400 micrograms of folic acid daily, ideally before conception and through at least the first trimester. This is the single most effective nutritional step for preventing neural tube defects. Most prenatal vitamins contain this amount. If you have a gene variant that makes it harder to process folic acid (the MTHFR mutation), the active form, methylfolate, is available in many prenatal formulas.
Food safety becomes more important during pregnancy because your immune system is naturally suppressed. Pregnant women are 10 times more likely to contract Listeria, a bacteria that can cause miscarriage. The CDC’s guidance is specific:
- Heat deli meats and hot dogs to 165°F before eating, or avoid them entirely
- Skip premade deli salads like store-bought potato salad, chicken salad, and coleslaw
- Avoid raw sprouts, unpasteurized juice, and raw milk or cheeses made from it
- Cook all poultry to 165°F and ground beef to 160°F
- Wash all fruits and vegetables thoroughly before eating
Keep caffeine under 200 mg per day, which is roughly one 12-ounce cup of brewed coffee. Higher intake has been associated with pregnancy loss and restricted fetal growth.
Exercise During Pregnancy
Physical activity doesn’t increase miscarriage risk. In fact, the current recommendation is at least 150 minutes of moderate-intensity aerobic exercise per week throughout pregnancy. That’s about 20 to 30 minutes on most days. Walking, swimming, stationary cycling, and prenatal yoga all count.
The old advice about keeping your heart rate below 140 beats per minute is outdated. Heart rate responses vary too much during pregnancy to be a reliable guide. Instead, use the “talk test”: if you can hold a conversation while exercising, your intensity is appropriate. If you were doing vigorous exercise before pregnancy, you can generally continue it. Activities to avoid are those with fall risk (skiing, horseback riding), contact sports, and anything that involves lying flat on your back for extended periods after the first trimester.
First-Trimester Bleeding and What It Means
Seeing blood in early pregnancy is alarming, but it doesn’t automatically mean something is wrong. In a study of over 4,500 pregnancies, about 19% of women reported spotting in the first trimester. Of those, roughly 91% continued with a viable pregnancy. Light spotting of short duration carried no increased miscarriage risk compared to women with no bleeding at all.
Heavier bleeding, bleeding that fills a pad, or bleeding accompanied by cramping warrants prompt evaluation. Your provider will likely check your hCG (pregnancy hormone) levels. In a healthy early pregnancy, hCG roughly doubles every two days through about 8 weeks of gestation. After that point, the hormone naturally rises more slowly, peaking around 10 weeks before leveling off. A single hCG number matters less than the trend over two or three draws spaced 48 hours apart. A rise of at least 53% over two days is considered normal for early pregnancies with initial levels below 5,000 IU/L.
Managing Chronic Conditions
If you have diabetes, thyroid disease, high blood pressure, or an autoimmune condition, getting these under tight control before and during pregnancy is one of the most impactful things you can do. Uncontrolled blood sugar in the first trimester significantly raises the risk of both miscarriage and birth defects. Thyroid hormones that are too high or too low can interfere with implantation and early development.
Some medications used to manage chronic conditions aren’t safe during pregnancy. If you’re planning to conceive, review your medications with your provider beforehand so substitutions can be made. This is especially important for blood pressure medications, certain psychiatric medications, and acne treatments containing retinoids.
Stress, Sleep, and Substance Use
Chronic high stress raises cortisol levels, which can affect blood flow to the uterus and overall hormonal balance. You don’t need to eliminate all stress (that’s impossible), but consistent sleep, even 15 minutes of daily relaxation, and social support all help regulate the stress response. Aim for seven to nine hours of sleep per night.
Alcohol, tobacco, and recreational drugs all increase miscarriage risk. There is no established safe amount of alcohol during pregnancy. Smoking restricts blood flow to the placenta, and even secondhand smoke exposure has been linked to complications. If you need help quitting, your provider can connect you with resources that are safe to use during pregnancy.