After one miscarriage, the risk of losing a second pregnancy is about 20%, which means roughly four out of five subsequent pregnancies succeed. That’s only modestly higher than the general miscarriage rate of 10% to 15% for all known pregnancies. The odds are in your favor, and there are concrete steps you can take to improve them further.
Get Tested for Treatable Causes
Most single miscarriages happen because of random chromosomal errors in the embryo, and no amount of preparation can prevent those. But some miscarriages stem from underlying conditions in the mother or father that will recur unless identified and treated. If you’ve had two or more losses (the threshold the European Society of Human Reproduction and Embryology uses to define recurrent pregnancy loss), your doctor can run a panel of tests targeting the most common fixable causes. Even after a single loss, some of these tests are worth discussing.
The major workup typically includes blood tests for clotting disorders, thyroid function, and blood sugar regulation, plus imaging of the uterus to check for structural problems. Each of these can reveal a specific, treatable reason for pregnancy loss.
Check Your Thyroid Levels
Thyroid function has a direct and well-documented effect on miscarriage risk. A large case-control study found that women with TSH levels between 2.5 and 4.87 had a 47% higher chance of miscarrying compared to women in the optimal range of 0.4 to 2.5. When TSH climbed above 4.87, the risk nearly doubled. These numbers matter because many women with mildly elevated TSH feel perfectly fine and wouldn’t suspect a problem without a blood test.
If your levels are high, treatment with thyroid hormone replacement is straightforward and can bring TSH into the target range before you conceive again. The American Thyroid Association recommends a first-trimester TSH target of 0.1 to 2.5, so ask for this to be checked before you start trying.
Screen for Antiphospholipid Syndrome
Antiphospholipid syndrome (APS) is an immune condition where your blood clots too easily, which can block the blood supply to a developing pregnancy. It’s one of the few causes of recurrent miscarriage with a clear, effective treatment. The American College of Rheumatology recommends that women who test positive for antiphospholipid antibodies and meet the criteria for obstetric APS take a combination of low-dose aspirin and heparin (a blood thinner given by injection) during pregnancy. This combined treatment results in successful pregnancies in most cases.
APS is diagnosed through blood tests that are repeated 12 weeks apart to confirm the result. If you’ve had recurrent losses and haven’t been tested, this should be near the top of your list.
Consider Sperm Quality Testing
Miscarriage evaluations almost always focus on the mother, but research increasingly points to the father’s contribution. Sperm DNA fragmentation, where the genetic material inside sperm cells is damaged, has been linked to higher miscarriage rates even when standard semen analysis looks completely normal. One study comparing men whose partners had recurrent losses to healthy controls found no differences in sperm count, motility, or morphology, yet the recurrent loss group had significantly more DNA damage.
Standard semen analysis simply doesn’t catch this. A specialized test called a sperm DNA fragmentation index (DFI) measures the integrity of sperm DNA directly. If fragmentation is high, lifestyle changes (reducing alcohol, quitting smoking, treating varicoceles) and a shorter interval between ejaculations can lower it. This is especially worth pursuing if no maternal cause has been found.
Look at Uterine Structure
Structural abnormalities in the uterus, such as a septum (a wall of tissue dividing the cavity), fibroids, or adhesions, can interfere with implantation or blood flow to the embryo. These are often present from birth and go undetected until pregnancy loss prompts investigation.
3D ultrasound is a good first-line tool because it’s noninvasive and has high accuracy for visualizing both the inside and outside shape of the uterus. Sonohysterography, where saline is infused into the uterus during an ultrasound, provides even more detail and has higher sensitivity than the older X-ray-based method (hysterosalpingography). If an abnormality is found, many can be corrected with minor surgery before your next pregnancy.
Genetic Testing for Both Partners
In about 3.75% of couples with recurrent pregnancy loss, one partner carries a chromosomal rearrangement called a balanced translocation. The carrier is healthy because all the genetic material is present, just rearranged, but their eggs or sperm can end up with missing or extra chromosomal segments, leading to nonviable embryos. The most commonly involved chromosomes are 8, 11, 14, and 21.
A simple blood test (karyotype) can detect this. Current guidelines suggest that routine karyotyping of both parents isn’t necessary for everyone, but it becomes more valuable if you’ve had a previous child with congenital anomalies or if testing of the miscarriage tissue showed an unbalanced chromosomal arrangement. If a translocation is found, preimplantation genetic testing during IVF can select embryos with normal chromosomes, dramatically improving the odds of a healthy pregnancy.
Manage Caffeine and Other Lifestyle Factors
Caffeine is one of the most studied lifestyle factors in miscarriage risk. The American College of Obstetricians and Gynecologists puts the safety threshold at less than 200 mg per day, roughly one 12-ounce cup of coffee. One large study found that women consuming 200 mg or more daily had more than double the miscarriage risk compared to non-consumers, while intake below that level showed no significant increase. If you’re a heavy coffee drinker, cutting back before conception is a simple protective step.
Other lifestyle factors with solid evidence behind them include maintaining a healthy BMI (both underweight and obesity increase miscarriage risk), avoiding alcohol entirely during early pregnancy, not smoking, and managing blood sugar if you have diabetes or prediabetes. None of these are guarantees, but together they create the healthiest possible environment for an embryo during the critical first trimester.
The Progesterone Question
Progesterone supplementation is one of the most commonly discussed interventions, and the evidence is more nuanced than many people realize. A large, well-designed trial published in the New England Journal of Medicine tested vaginal progesterone in women who had bleeding during early pregnancy and found no significant improvement in live birth rates compared to placebo. An earlier trial in women with a history of unexplained recurrent miscarriage also found no benefit.
The American College of Obstetricians and Gynecologists takes a cautious position: evidence supporting progesterone for threatened miscarriage is inconclusive, though women who have experienced three or more prior losses may benefit from first-trimester progesterone therapy. If your doctor recommends it, it’s unlikely to cause harm, but it shouldn’t be considered a proven solution on its own.
Timing Your Next Pregnancy
There’s no medical requirement to wait a specific number of cycles before trying again after an early miscarriage. Some research suggests that conceiving within three months of a loss actually has equal or better outcomes compared to waiting longer. Your body typically ovulates again within two to four weeks after an early loss, so physical readiness returns quickly. Emotional readiness is a different matter entirely, and only you can gauge when the time feels right.
What does help is using the interval to complete any testing, optimize thyroid levels, start prenatal vitamins with adequate folate, and address modifiable risk factors. Walking into your next pregnancy with a clear picture of your health gives you both the best medical odds and a greater sense of control over a process that can feel deeply uncertain.