During unprotected sex, men release semen that contains millions of sperm cells. If these sperm successfully enter the woman’s vagina, they can fertilise an egg and cause pregnancy.
There are many signs that sperm entered the body, including vaginal discharge, pain or itching and a missed or late period. However, not all of these symptoms guarantee sperm made it in and fertilised an egg.
During Oral Sex
If you’re a woman and get oral sex, you may not feel the sperm in your mouth or throat. This is because sperm will reach your stomach where it’ll be killed and broken down by acids in the stomach and proteins in the small intestine. Only a negligible amount of these breakdown products will be absorbed into the body.
Sperm is a type of cell produced in the testicles and is essential for sexual reproduction. It carries genetic material that is passed on to offspring when it fertilizes an egg. Sperm production and quality can be affected by various factors, including age, lifestyle, and health conditions.
During oral sex, a man can ejaculate in his partner’s mouth or throat, and the woman can either spit it out or swallow it. This can lead to pregnancy if the semen comes in contact with her vagina circuitously. It may also lead to STIs such as herpes, chlamydia, gonorrhea, and syphilis.
Both partners should always use protection during sexual activity. This can include a condom during fellatio, or a dental dam during cunnilingus and analingus (oral sex of the vulva and/or anus). Using protection prevents skin-to-skin contact which is how most STIs are passed. Women should also visit a doctor for testing and further guidance if they think they might be pregnant.
In the Cervix
The cervix is a thin strip of tissue that connects the vagina to the uterus. It’s about an inch long and shaped like a donut, with a narrow opening at either end that look a bit like pursed lips. The cervix is covered with stratified squamous non-keratinized epithelium and has glands that produce cervical fluid, or mucus. This is the stuff that you see on your underwear or toilet paper when you wipe (1, 2). Cervical fluid has an alkaline pH and is especially wet and stretchy around ovulation. That makes it much more hospitable to sperm than the acidic vagina (2, 3).
After a man ejaculates, some of the sperm travel through the cervical mucus in a process called “rapid transport” and reach the internal os (the point where the cervix ends and the uterus begins) within 5-20 minutes (3, 4). However, sperm that enter the body through unprotected sex have a very low chance of fertilising an egg. It takes only one sperm out of the million that are released to find and penetrate an egg, and even then pregnancy isn’t guaranteed.
The sperm that do successfully reach the egg can take up to five days to pass through the cervix (5, 6). Then they must break through a group of cells known as the cumulus oophorus that surround the egg, and then penetrate the egg itself. Once they do this, they must then find and bind to the egg’s nucleus.
In the Stomach
Sperm is a type of cell produced in the male reproductive system, specifically in the testicles. It is essential for sexual reproduction and contains genetic material in the form of DNA that is passed on to offspring after fertilization with an egg. It also has a tail, known as the flagellum, that propels it forward during sexual intercourse.
In the case of oral sex, a woman may feel sperm enter her mouth as the man ejaculates in her mouth or she can spit it out. However, it is not always possible to tell whether sperm has entered the body because it is impossible to feel the microscopic sperm with the naked eye or fingers.
Penetration-based sexual intercourse usually results in orgasm, which causes ejaculation of sperm. This is the most common way that sperm enters the body during sexual activity. During this process, the sperm cells travel up through the cervix and then into the uterus. It is important for the sperm to reach the egg so that it can be fertilized, which will result in pregnancy.
While there are several ways to confirm sperm entry into the body, including vaginal wetness and a change in vaginal discharge, it is best to visit a doctor for confirmation and guidance. A doctor can perform a pelvic exam and a pregnancy test to determine if you are pregnant.
In the Uterus
Sperm enters the female body through an opening in the vagina called the cervix, which is the narrow entrance into the uterus. The uterus is a hard, pear-shaped structure with a tiny cavity inside where a fertilized egg will implant and grow during nine months into a full-size baby (5). Sperm can enter the cervix through sexual activity, but only during the fertile window of the menstrual cycle. The closer to ovulation, the easier it is for sperm to make their way from the vulva to the uterus (1).
During sexual intercourse, a man’s penis is inserted into the woman’s vagina for penetration. This usually results in orgasm and ejaculation of semen, which contains millions of sperm (7). The sperm then swims through the woman’s reproductive tract to reach her egg.
Women can feel sperm entering their bodies in several ways, including changes in vaginal discharge and sensations of fullness or pressure in the lower abdomen. However, these symptoms can also be caused by many other factors and are not a guarantee that sperm has reached the egg.
If a woman experiences these symptoms and is concerned she may be pregnant, she should take a home pregnancy test or visit her doctor for confirmation and medical examinations. In some cases, a doctor can also administer a blood test to check for the presence of the pregnancy hormone human chorionic gonadotropin (HCG), which indicates that an egg has been fertilized by sperm and is developing into a fetus (8).
