Can You Get Pregnant After an HSG Test? What Studies Show

One of the most encouraging findings in fertility medicine is that many women conceive naturally in the months following an HSG test. This is not coincidence — multiple clinical studies have demonstrated that the hysterosalpingography procedure itself can improve fertility through what researchers call the "flushing effect." Understanding the evidence behind this phenomenon can help you maximize your chances of conception after your HSG procedure.

The HSG Fertility Flushing Effect: How It Works

During an HSG test, contrast dye is injected through the cervix and flows through the uterine cavity and fallopian tubes under pressure. This pressurized flow of contrast can mechanically dislodge minor obstructions such as mucus plugs, small debris, and thin adhesions within the fallopian tubes.

Beyond the mechanical flushing, researchers believe the contrast dye may also create a more favorable environment for conception. Oil-based contrast, in particular, may coat the inner lining of the tubes, reducing inflammation and creating a smoother surface for egg transport. Some theories suggest that the contrast material may also have immunomodulatory effects that enhance embryo implantation in the uterus.

What the Research Shows: Key Clinical Studies

The H2Oil Trial (NEJM, 2017)

The most significant study on post-HSG fertility is the H2Oil trial, published in the New England Journal of Medicine in 2017. This large, multicenter, randomized controlled trial involving 1,119 women compared pregnancy outcomes between oil-based contrast (Lipiodol) and water-based contrast during HSG.

The results were striking: within six months of the HSG procedure, 40% of women in the oil-based contrast group became pregnant, compared to 29% in the water-based contrast group. This represents a significant clinical difference and suggests that oil-based contrast provides a stronger fertility-enhancing effect.

The FLUSH Trial (Lancet, 2019)

A subsequent study, the FLUSH trial published in The Lancet, further examined the fertility benefits of tubal flushing. This trial focused on whether flushing with oil-based contrast improved live birth rates. The findings supported the earlier H2Oil results, confirming that oil-based contrast flushing during HSG was associated with higher pregnancy and live birth rates compared to no intervention.

Earlier Meta-Analyses

Even before the H2Oil trial, several meta-analyses (systematic reviews of multiple studies) had suggested that HSG with oil-based contrast was associated with improved pregnancy rates. A 2015 Cochrane review of 12 studies found that oil-based contrast during HSG increased the odds of pregnancy and live birth compared to no treatment, though the evidence was considered moderate quality at the time.

Oil-Based vs. Water-Based Contrast: Which Is Better for Fertility?

Factor	Oil-Based Contrast (Lipiodol)	Water-Based Contrast
Pregnancy rate within 6 months	~40% (H2Oil trial)	~29% (H2Oil trial)
Flushing effectiveness	Stronger due to viscosity	Less viscous, weaker flushing
Image quality	Good, slightly less sharp	Very sharp and clear
Cost	Higher	Lower
Absorption	Slower (stays in tubes longer)	Rapid (absorbed quickly)
Safety profile	Very safe; rare oil embolism risk	Very safe

Data based on the H2Oil randomized controlled trial (NEJM 2017) and subsequent studies.

The choice between oil-based and water-based contrast is a clinical decision made between you and your doctor. While oil-based contrast shows stronger fertility benefits, both types are considered safe and effective for diagnostic purposes. Some facilities prefer water-based contrast for its sharper image quality, while others offer oil-based as the default given the fertility evidence.

How Long Does the Fertility Boost Last?

The fertility-enhancing effect of HSG appears to be most pronounced in the first three to six months following the procedure. Most studies report that the majority of post-HSG pregnancies occur within this window. After six months, the benefit appears to diminish, likely because any cleared debris or improved tubal conditions gradually return to their pre-procedure state.

This timeline is important for treatment planning. Your fertility specialist may recommend trying to conceive naturally during this three-to-six-month "fertility window" before considering more advanced interventions like IUI or IVF.

Month-by-Month Guide: What to Do After Your HSG Test

Month 1: Recovery and Resuming

After your HSG test, you can resume trying to conceive in the next menstrual cycle. There is no medical reason to wait additional cycles unless your doctor advises otherwise. Use ovulation tracking methods (ovulation predictor kits, basal body temperature, or cervical mucus monitoring) to time intercourse optimally.

Months 2-3: Active Trying

Continue regular intercourse timed around ovulation. Maintain a healthy lifestyle including balanced nutrition, regular exercise, stress management, and adequate sleep. Take prenatal vitamins including folic acid. If you have not already, discuss any other fertility-optimizing steps with your gynecologist.

Months 4-6: Assessment Period

If conception has not occurred by month four to six post-HSG, it is a good time to reassess your fertility plan with your specialist. They may recommend additional testing (such as semen analysis for your partner if not yet done, or hormone level checks), or discuss whether to proceed with treatment options like timed intercourse with medication, IUI, or IVF.

Beyond 6 Months: Next Steps

If pregnancy has not occurred within six months after HSG, the fertility-enhancing effect has likely waned. At this point, your fertility specialist will typically recommend a more structured approach. For many couples, this means moving toward IUI (intrauterine insemination) or IVF (in vitro fertilization) depending on the specific diagnosis, age, and overall fertility factors.

Factors That Influence Post-HSG Pregnancy Rates

Age: Women under 35 generally have higher post-HSG pregnancy rates than those over 35
Tubal status: Women with open tubes (confirmed by HSG) benefit the most from the flushing effect
Type of contrast: Oil-based contrast is associated with higher pregnancy rates than water-based
Duration of infertility: Couples with shorter duration of unexplained infertility tend to have better outcomes
Male factor: Normal semen analysis increases the likelihood of post-HSG natural conception
Ovulation: Regular ovulation is essential for natural conception after HSG
Overall health: A healthy lifestyle, normal BMI, and absence of conditions like PCOS or endometriosis improve chances

When to Move from Natural Trying to IVF

The decision to transition from natural conception to assisted reproduction is personal and depends on multiple factors. However, general guidelines suggest considering IVF in the following situations:

Both fallopian tubes are blocked (IVF bypasses the tubes entirely)
Severe male factor infertility is present (very low sperm count or motility)
The woman is over 38 and has been trying for more than 6 months
Previous IUI attempts have been unsuccessful (typically after 3-4 cycles)
Endometriosis, PCOS, or other conditions significantly reduce natural conception chances
The couple prefers a more aggressive approach to minimize time to conception

Your fertility specialist will help you weigh the options and create a personalized treatment plan based on your HSG results and overall fertility evaluation.

Tips to Maximize Your Chances After HSG

Track ovulation accurately using predictor kits, apps, or ultrasound monitoring
Time intercourse for the fertile window (day of ovulation and the two days before)
Take prenatal vitamins with at least 400mcg folic acid daily
Maintain a healthy weight — both overweight and underweight can affect fertility
Limit caffeine intake to less than 200mg per day (about one cup of coffee)
Avoid smoking and excessive alcohol — both significantly reduce fertility
Manage stress through relaxation techniques, exercise, or counseling
Ensure your partner has had a semen analysis to rule out male factor issues

Real Expectations: Understanding the Statistics

While the post-HSG fertility boost is real and clinically significant, it is important to maintain realistic expectations. Even with the flushing effect, pregnancy is not guaranteed. In the H2Oil trial, 40% of women in the oil-based group became pregnant within six months — this means 60% did not, and many of those women went on to conceive through other methods.

HSG is one important step in the fertility journey, not a standalone treatment. It provides valuable diagnostic information and may enhance your chances, but it works best as part of a comprehensive fertility evaluation guided by experienced specialists.

HSG and Fertility Support at DCDC

At Doctors Clinic Diagnostic Center in Dubai Healthcare City, our experienced consultant radiologists perform HSG procedures with attention to both diagnostic accuracy and the therapeutic potential of the procedure. We discuss contrast options with each patient and provide detailed results that support your fertility planning.

Our team works closely with referring gynecologists and fertility clinics across Dubai to ensure your HSG results are integrated into your overall treatment plan. Whether you conceive naturally in the months following HSG or need additional fertility support, we are here to provide the diagnostic foundation for your next steps.

Ready to Take the Next Step in Your Fertility Journey?

At Doctors Clinic Diagnostic Center, our HSG testing combines accurate diagnosis with the potential fertility-enhancing flushing effect. Contact us to learn about your options and schedule your procedure.

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Mga Madalas Itanong

You can resume trying to conceive in the next menstrual cycle after your HSG test. There is no medical requirement to wait additional cycles. The fertility-enhancing effect is strongest in the first 3-6 months after the procedure.

Yes. The H2Oil trial published in the New England Journal of Medicine found that 40% of women who had HSG with oil-based contrast became pregnant within 6 months, compared to 29% with water-based contrast. The difference was statistically significant.

The fertility-enhancing effect appears strongest in the first 3 to 6 months after the procedure. After this period, the benefit gradually diminishes. This is why fertility specialists often recommend actively trying during this window.

If the blockage is minor (such as a mucus plug), the HSG flushing effect may clear it. However, if the tubes are significantly blocked, HSG will diagnose the problem but may not resolve it. Further treatment such as surgery or IVF may be needed.

If pregnancy has not occurred within 6 months after HSG, discuss next steps with your fertility specialist. Options may include medicated cycles, IUI, or IVF depending on your diagnosis, age, and other fertility factors.

HSG is primarily a diagnostic test, but the fertility-enhancing flushing effect gives it a therapeutic benefit as well. This dual role is one reason why fertility specialists recommend HSG early in the evaluation process.

Final Thoughts

The evidence is clear: an HSG test can do more than just diagnose — it may actively improve your chances of getting pregnant. The fertility flushing effect, particularly with oil-based contrast, has been validated by large clinical trials and offers real hope for couples facing unexplained infertility or minor tubal issues.

At Doctors Clinic Diagnostic Center, we view every HSG procedure as both a diagnostic opportunity and a potential step toward conception. By choosing experienced radiologists and discussing contrast options with your care team, you give yourself the best chance of benefiting from both the diagnostic and therapeutic aspects of this important procedure. For details on pricing and what is included, see our HSG test cost in Dubai guide.

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Isinulat ni

Dr. Osama Elzamzami

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Consultant Radiologist

MD, Radiology

Dr. Osama Elzamzami is a Consultant Radiologist specializing in diagnostic imaging including MRI, CT, ultrasound, and fluoroscopy procedures such as HSG at DCDC Dubai Healthcare City.