Let's address this head-on: the idea that female orgasm helps conception is one of the most persistent myths in fertility. It's appealing because it suggests that pleasure and reproduction are linked—that the body "knows" when sex is good and rewards you with a baby.
The theory even has a scientific-sounding name: the "upsuck hypothesis." The claim is that orgasmic contractions create a vacuum effect that pulls sperm up through the cervix and toward the egg, improving your chances of conception.
So is there anything to it?
The Upsuck Hypothesis: Where It Came From
The idea traces back to a 1993 study by researchers Robin Baker and Mark Bellis. They measured what they delicately called "flowback"—the semen that leaks out after sex—and claimed that women retained more sperm when they had an orgasm, especially if it occurred after their partner ejaculated.
Their conclusion: female orgasm serves a reproductive function by selectively retaining sperm from desirable partners. It was an evolutionary story that made for great headlines.
There was just one problem.
The primary evidence for the upsuck hypothesis came from just two experiments on a single woman. The broader claims about sperm retention were based on self-reported data and indirect measurements. It was an intriguing hypothesis, not a proven fact.
Why Scientists Now Call It a "Zombie Hypothesis"
Sexual physiologist Roy Levin, who has studied this question extensively, refers to upsuck as a "zombie hypothesis"—a dead idea that refuses to lie down.
Here's the key anatomical problem: during sexual arousal, the vagina undergoes something called "tenting." The inner two-thirds of the vagina expand and elongate, and the cervix is pulled upward and away from the semen pool. At the exact moment of orgasm, the cervix is actually in the worst possible position to "suck up" anything.
The most comprehensive evidence comes from twin studies examining over 16,000 women. Researchers Brendan Zietsch and Pekka Santtila looked for any correlation between female orgasm rate and number of offspring. After controlling for relationship length and how often couples had sex, they found... nothing.
No correlation between orgasm frequency and fertility. No genetic link between orgasm capacity and reproductive success. Zero evidence that orgasm helps conception.
"The balance of evidence does not support any positive role for female orgasm in human reproduction."
— Roy Levin, sexual physiology researcher
But Wait—What About Uterine Contractions?
A more nuanced version of the theory focuses on uterine contractions during orgasm. These contractions are real—they've been measured. And some researchers have speculated that they might help transport sperm through the reproductive tract.
The problem is timing and direction. Sperm reach the fallopian tubes within minutes of ejaculation—often before the woman has had an orgasm. And the contractions during orgasm don't follow a coordinated pattern that would consistently push sperm in the right direction.
One study did find that oxytocin (released during orgasm) can increase uterine contractions, but there's no evidence this translates to improved conception rates in real-world conditions.
So Does Orgasm Matter At All?
Here's where we get practical. Female orgasm doesn't appear to directly improve your odds of conceiving. But that doesn't mean pleasure is irrelevant to fertility. Here's why:
1. Enjoyment Increases Frequency
Couples who enjoy sex have more of it. And more sex during the fertile window = more chances to conceive. If focusing on orgasm makes sex better and more frequent, that indirectly helps.
2. Stress Reduction Matters
Good sex reduces stress hormones. And stress genuinely does affect fertility—women with high levels of the stress biomarker alpha-amylase have twice the risk of infertility. If orgasm helps you relax, that's valuable.
3. Relationship Health Supports the Journey
Trying to conceive can strain a relationship. Maintaining a satisfying sex life—where both partners' pleasure matters—keeps the connection strong during what can be a difficult process.
Female orgasm doesn't mechanically improve your chances of conception. But sex that feels good keeps couples connected, reduces stress, and encourages frequency—all of which support fertility indirectly. So don't stress about whether you're orgasming at the "right" time. Focus on enjoying each other.
What Actually Does Help Conception?
If orgasm isn't the fertility hack you hoped for, what actually moves the needle? Here's what research supports:
- Timing relative to ovulation — Sex in the 1-2 days before ovulation has the highest success rate
- Frequency — Every 1-2 days during the fertile window is optimal
- Sperm quality — Fresh sperm (from recent, not saved-up, ejaculation) have better motility and DNA integrity
- Stress management — High stress biomarkers double infertility risk
- Basic health factors — Sleep, moderate exercise, avoiding excessive alcohol
Position doesn't matter. Lying down afterward doesn't have strong evidence. Female orgasm doesn't boost conception. What matters is getting healthy sperm to healthy egg at the right time—and being patient while you try.
Track Your Fertile Window
The timing of sex matters far more than whether you orgasm. Use our free calculator to find your most fertile days.
Calculate Ovulation →Why Does This Myth Persist?
The upsuck hypothesis refuses to die because it's a satisfying story. It suggests that female pleasure has evolutionary importance, that the body "knows" good sex from bad, and that orgasm is nature's way of selecting for compatible partners.
It's also been repeated in popular media so often that it feels like established fact. Books, magazines, and even some fertility websites still cite the Baker and Bellis research without mentioning its serious limitations.
The truth is less romantic but more liberating: your orgasm is for you. It doesn't need a reproductive justification. The pressure to "come at the right time" or feel guilty about not having an orgasm can actually make sex worse—and stress worse—during an already challenging time.
Enjoy sex because it feels good and connects you with your partner. That's reason enough.