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"But what about the pre-cum?"

An evaluation of the pre-ejaculate in withdrawal or "pulling out"


Why Withdrawal?

“Pulling out” or withdrawal is a method that people use to prevent pregnancy. It's been around for a long time and lots of people use it. However, we--scientists--STILL don't know very much about how to use it and how effective it really is. Some men have used withdrawal their whole lives without any unwanted pregnancies, whereas others have been less successful…

We want to know why!

Our Questions:

  • If withdrawal is used correctly, is there sperm released in the pre-ejaculatory fluid ("pre-cum") that can make a woman pregnant?

  • What makes someone more likely to have sperm in their pre-ejaculate?

  • What affects whether someone will have sperm in their pre-ejaculate? Age? Experience? Sperm count? Something else?

What we already know:

In 2012, Steven Killick and his UK lab tried to answer the question:
"Are there sperm released in pre-ejaculatory fluid that could make someone pregnant?

After examining 40 samples from 27 men, they found that only 37% of the pre-ejaculatory fluid samples had motile sperm (sperm that could successfully travel to an egg and fertilize it). They also noted that some men consistently had sperm in their pre-ejaculate and some did not!


Now in 2019, Dr. Jasmine Patel and her team at the EMERGE Lab are repeating this study with more critical attention and deeper questions. But we need your help... 

Our Study:

There are 3 parts to this study:

  1. Survey: Couples will individually be asked to share their experiences with and use of withdrawal.

  2. At the lab: Male participants will be asked to come to our research center to collect and provide both pre-ejaculate and ejaculate samples. These samples will be examined under the microscope to compare their sperm concentrations.

  3. At home: Female partners of these men will self-swab their vaginas before sex and  after withdrawal is used for each time they use withdrawal with sex for a period of 2-3 months.



How To Get Involved:

Call or Text "withdrawal": (323) 797-4336

Study Requirements:

  • Time: 2 to 3 month commitment

  • Compensation: Participants will be compensated up to $170 each for completing this study. 

  • Location: LAC/USC Medical Center, Section of Family Planning

    • 1200 N. State Street, Clinic Tower, A3A, Los Angeles, CA 90033

    • Parking is free!



Dr. Jasmine Patel (Principal Investigator)

Dr. Brian Nguyen

Helena Galinson

Meredith Xepoleas

This research has been approved by the USC IRB: #19-00124

Are you a couple

that uses or has used withdrawal?

Interested in being part of a study to learn about the withdrawal method?

Come Join Us!

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