Contraception is sometimes called birth control or family planning. Some of the many contraception methods are more effective than others; all have advantages and disadvantages.


  • Contraception is also sometimes called birth control or family planning.
  • There are many different contraceptive methods, including the use of hormone medications, intrauterine contraceptive devices, barrier contraception, periods of abstaining from sex, and surgery. Some methods are more effective than others; all have advantages and disadvantages.
  • Reasons for using contraception include personal desires (to never have, postpone, or stop having children); medical conditions that could threaten the health of mother or child; and social concerns about environmental effects of over-population.
  • The effectiveness of the different methods is often given in percentage. Another more accurate dimension for effectiveness is the so-called Pearl Index which measures the number of pregnancies in 100 women, using a contraceptive technique for one year. For example, the Pearl Index of the “pill” is less than 1 which means there will be less than one pregnancy among 100 women who are using the pill correctly for one year.

“Natural” methods

These methods do not make use of any contraceptive devices or medications.

Natural family planning (rhythm method)

This involves a woman keeping a menstrual calendar to enable her to accurately predict her fertile period. Most women ovulate about 14 days before the start of the next menstrual period which, in a 28 day cycle, is at the midpoint of the cycle. An unfertilised egg may live two days, while sperms were found to stay alive in the genital tract up to 10 days after intercourse although they may be able to cause fertilisation only for about four days. Thus, intercourse should be avoided during the phase when there is the greatest chance for sperms and eggs to meet.

  • Advantage: No hormones are taken, so there are no side-effects from these.
  • Disadvantage: It is not a very reliable method of contraception.
  • Effectiveness: If the fertile time is predicted correctly with the help of a menstrual calendar and additional use of basal body temperature, the effectiveness is around 80%.

Coitus interruptus (withdrawal)

  • Involves removing the penis from the vagina immediately before ejaculation.
  • By preventing sperms to enter the vagina, fertilisation does not occur.
  • Effectiveness depends on the male's ability to withdraw before ejaculation. Often, some sperms are deposited in the vagina before or during withdrawal, making this method not very reliable.
  • Disadvantage: Does not provide protection against sexually transmitted infections (STIs). STI-organisms can be transmitted by direct contact with surface lesions in both partners and from vaginal and pre-ejaculatory fluid.
  • Effectiveness: Pearl Index of 8-17.


  • In nursing mothers, ovulation is often suppressed which has the advantage that breastfeeding acts as a contraceptive measure. However, this is not a reliable method and breastfeeding women are often advised by their doctor to use the “mini-pill” to provide additional protection. The “mini-pill” contains only progestogens which has the advantage that it will not interfere with milk production.  The importance with this pill is that it must be taken every day at the same time.
  • Once breastfeeding is stopped, a more effective contraceptive method should be used.

Barrier Methods

Barrier contraceptive devices physically block the access of sperms to a woman's uterus and fallopian tubes. They include the diaphragm and cervical cap, the male and female condom, and the spermicides (“sperm killers”) in form of foams, creams and gels.

Diaphragms and cervical caps

Diaphragms and cervical caps are not commonly used in South Africa because they are not always easily available. The use of these devices requires an initial assessment by a medical practitioner/gynaecologist, whereby a gynaecological examination is performed to choose the correct size. The doctor will instruct the woman how to insert the device correctly and how to remove it again. Effectiveness: If 100 women use the diaphragm or cap together with a spermicide, 5 to 20 users will become pregnant within one year.

The diaphragm

  • Consists of a soft, dome-shaped rubber or silicone at the centre and a firm outer ring. It is positioned over the cervix to prevent sperms from entering the uterus.
  • Should be used with a spermicide which is applied to both sides of the diaphragm before being placed over the cervix a few minutes to six hours before intercourse. It should be left in place for at least six hours after intercourse. For intercourse after the six-hour period, or repeated intercourse within this period, fresh spermicide should be administered in the vagina with the diaphragm still in place. The diaphragm should not be left in the vagina longer than 24 hours.
  • Can be fairly effective if used correctly with a spermicidal cream, and if a doctor is consulted regularly to assess the correct size and fitting (especially after childbirth).

Cervical cap (not available in South Africa)

  • Works similarly to the diaphragm, and is initially also fitted by a health professional.
  • Smaller and firmer than the diaphragm, cup-shaped with a round rim, made of slightly thicker rubber or plastic.
  • Thirty minutes to 40 hours before intercourse, the cap is filled with spermicide and inserted over the cervix. It protects for 48 hours and for multiple acts of intercourse within this time. Should be kept in place for at least eight hours after intercourse, but not longer than 48 hours.
  • Advantage:  Does not affect a woman's hormones like the pill or injection. Does not interfere with intercourse if inserted ahead of time.

Disadvantages of diaphragms and cervical caps:

  • The devices are not as effective as other contraceptive methods.
  • Some women find it difficult to insert the devices properly.
  • The use of the devices requires regular re-assessment for size and fitting, particularly after pregnancy or change in body weight.

Male condom

  • The male condom is a very thin synthetic rubber or latex sheath which is drawn over the penis to prevent sperms from entering the vagina.
  • Prevents direct contact with disease-causing organisms during intercourse.
  • Can be used only once. If intercourse is repeated, the penis should be dried and a new condom applied.  
  • Some are prelubricated. Lubricants do not provide more contraception or STI protection. Oil-based lubricants, such as petroleum jelly (Vaseline), lotions, or massage or baby oil, can weaken the material and should be avoided. Other lubricants (water-based  or K-Y jelly) can be used with latex condoms. Lubricated condoms that include a spermicide, such as nonoxynol-9, may decrease the possibility of pregnancy and transmission of certain STI-organisms (for example trichomonas but probably not gonorrhoea, chlamydia or HIV). Because condoms can break, their effectiveness can be increased by using an additional spermicide.
  • The condom should be applied before any genital contact to prevent pregnancy and STI.
  • Advantages:
    • It is easy to use and fairly effective if handled properly.
    • Does not require a prescription, is inexpensive and easily available – can be obtained at pharmacies, family planning clinics and from vending machines.
    • Has no systemic side-effects.
    • After abstinence and mutual monogamy, condoms are the next most effective method of reducing risk of infection from STIs.  
    • Has slight tourniquet effect on outer veins of the penis, which may benefit men who have difficulty maintaining erection.
  • Disadvantages:
    • The condom may break or slip off during intercourse.
    • Interrupts lovemaking. Since the condom must be put on when the penis is erect and before contact is made between the penis and vagina, there is usually a brief interruption during foreplay. 
    • Some pre-planning is needed to have a condom available for intercourse.  
    • May cause loss of sensation – no direct contact between the penis and vagina. Some men are unable to maintain an erection when wearing a condom.
    • If there is insufficient lubrication, the condom may cause friction  making intercourse uncomfortable. (Lubricated condoms may alleviate this).
    • Rarely, allergic reactions to latex condoms can occur.

    Effectiveness: Condom use has a Pearl Index of 3-15. This variation is due to:

    • Occasional rupture of a condom during intercourse.
    • Spillage of semen during withdrawal.
    • Delayed placement of a condom on the penis (penis comes into contact with vagina before condom is applied).
    • Failure to use a condom during each act of intercourse.
    • Manufacture fault of condom, although this risk is very small.

How to use a condom

  • Remove the condom from its package, being careful not to tear or poke a hole in it while pulling it out. Unroll the condom slightly before putting it on the penis. This leaves enough space for semen collection and prevents the condom from being stretched too tightly over the glans (tip) of the penis.
  • If the condom has a receptacle at the tip (to collect semen), place the condom against the glans of the penis and carefully roll it down over the shaft of the penis. If there is no receptacle at the end, leave a small space between the condom and the tip of the penis – otherwise semen may move up between the penis and the condom and come out at the base. Be sure there is no air between the penis and the condom: this can cause the condom to break. While applying the condom, the walls of the teat (or plain end) should be held together to expel air.
  • Immediately after ejaculation, carefully withdraw the penis from the vagina so that semen cannot leak out of the condom as the erection is lost. Hold the condom at the base of the penis while it is withdrawn.
  • Make sure to have condoms available and conveniently located at the time of a sexual encounter.
  • Don't carry condoms in your wallet or pocket for long periods. Friction can cause tiny holes in the condom.
  • Don't use condoms that are brittle, sticky or discoloured. These are probably old.
  • If the package of a condom is damaged, so may be the condom.
  • If you feel the condom is breaking during intercourse, stop immediately and put on a new one. If ejaculation occurs with a broken condom, insert a nonoxynol-9 spermicide, if available, to reduce risk of pregnancy and consider emergency contraception.  
  • Remember that pregnancy or transmission of STD-organisms can also occur without ejaculation.
  • Store condoms in a cool, dry place away from sunlight.

Female condom (Femidom)

  • Is a lubricated, thin polyurethane sac with two soft rings at each end. The larger open ring stays outside the vagina, covering part of the perineum and labia during intercourse, while the smaller ring, covered with polyurethane, fits loosely over the cervix.
  • Resembles a male condom but is larger.
  • Available without prescription, but only in a few clinics and some pharmacies.
  • Less effective protection than the male condom against some STIs, including AIDS
  • Intended for one-time use.
  • Not for use with a male condom because both may not stay in place.
  • The female condom should be used together with a spermicidal agent.
  • Advantages:
    • It is less likely to rupture than the male condom and is more resistant to chemicals.
    • Allows the woman to take responsibility for pregnancy and disease prevention.
    • Can be inserted up to eight hours before intercourse but should be removed immediately after ejaculation.
  • Disadvantages
    • Has a minimally higher failure rate than the male condom (Pearl Index: 5–15).
    • Requires some practice to be used correctly.
    • May be uncomfortable.


  • Sperm-killing chemicals available as gel, foam, jelly, foaming tablets, vaginal suppositories or cream.
  • Are designed to be used in conjunction with diaphragms, caps or condoms. If used on their own, they carry a higher failure rate.
  • Are inserted into the vagina, close to the cervix.
  • Some products require a waiting period before becoming active inside the vagina. Others must be inserted immediately before intercourse.
  • Contain a substance which either immobilises or kills sperms to prevent them from fertilising an egg.
  • One dose of spermicide is usually effective for one hour. For repeated intercourse, additional spermicide should be applied. After intercourse, the spermicide should remain in place for at least six to eight hours to ensure it's effect on all sperms.  During this time, tampons and vaginal douches or rinsing of the vagina must be avoided.
  • No prescription needed; easily obtainable from most pharmacies.
  • Spermicidal creams and jellies provide added lubrication, often needed with a condom.

Intrauterine device (IUD)

  • Small, plastic, often T-shaped device, surrounded by a copper wire or containing hormones, inserted into the uterus.
  • Changes physical and chemical environment of uterine cavity, thereby preventing sperms to fertilise an egg or possibly inhibiting implantation of a fertilised egg.
  • Inserted by a medical professional.
  • Depending on the type, it is worn from one to five or even seven years before requiring replacement.
  • Copper IUDs consist of polyethylene plastic with a copper wire wound around the stem.
  • Hormone containing IUDs are plastic devices with a hollow stem filled with a progestogen hormone.
  • Each IUD has thin threads attached to the lower end of the stem which are used for removal and also for checking that the device is still in position.
  • Require regular check-ups to ensure they are in place.
  • Some women experience more painful periods after IUD insertion; this usually settles once the body adjusts.
  • Effectiveness:  IUDs are a highly effective method of contraception with a Pearl Index of 0.3-0.8. This means that only eight out of every 1000 women wearing an IUD will become pregnant in the first year of use. Fewer pregnancies occur with continued use.
  • Advantages:
    • It is immediately effective.
    • It is especially suitable for patients older than 35 years and for those who have completed their families.
    • It does not interfere with sexual intercourse.
    • It is long acting.
    • There are no systemic side-effects.
    • Can be used as emergency contraception (apart from the progestogen-containing IUD).
  • Disadvantages
    • Can cause heavy, longer periods or abnormal bleeding.
    • Complications occur most often during and immediately after insertion. Serious complications (e.g. perforation of the uterus) are rare.
    • Does not protect against contamination with micro-organisms causing STI and pelvic inflammatory disease (PID).
    • Other possibility: Does not as effectively prevent the development of an ectopic pregnancy (fertilised egg implanting in the fallopian tube).
    • It can be expelled.

When to consult a doctor
If, while using an IUD, any of the following are experienced:

  • Menstrual irregularities – missed period or spotting
  • Severe abdominal cramps with or without  shoulder pain
  • Painful sexual intercourse
  • Vaginal discharge

The insertion of an IUD is not suitable for women with:

  • Recurrent vaginal infections
  • Heavy, irregular bleeding
  • A history of pelvic infection or ectopic pregnancy
  • More than one sexual partner (therefore at higher risk for acquiring STIs)
  • Not having completed their family and still intend to have children
  • Suspicion of being pregnant


    • Surgical sterilisation is an option for people who do not want children in the future.
    • Both men and women can be sterilised. Adequate pre-operative counselling is necessary.
    • When a woman is sterilised, her fallopian tubes, which allow sperms to swim to the ovaries and fertilised eggs to move to the uterus, are surgically closed.
    • Male sterilisation, vasectomy, involves closing the vas deferens, the tubes which carry sperms from the testicles to the penis. Vasectomy is a more minor surgical procedure than female sterilisation, usually under 30 minutes. Vasectomy has no effect on a man's testicular function or sexual performance.  
    • While female sterilisation is effective immediately, vasectomised men will only be classified as sterile if a semen analysis three months after the operation confirms absence of sperms in the ejaculatory fluid.
    • Sterilisation is considered to be permanent, although it can be reversed using microsurgery. This usually carries a fair success rate for subsequent pregnancy if performed by an expert microsurgical gynaecologist for female sterilisation or urologist for male sterilisation. Should microsurgery fail, the chances of pregnancy can be improved with assisted reproduction (in vitro fertilisation, ICSI).  
    • Advantages: Effective, permanent.
    • Disadvantages: Not easily reversible if the wish for another child arises again.
    • Effectiveness: Although the procedure may fail in a small percentage of cases, it is the most effective contraceptive method.    

    Hormonal methods

    • These are contraceptives for women and include oral contraceptives, commonly known as the “pill”, as well as hormonal injections, implants and vaginal rings, all containing synthetic hormones. Their method of action is to stop the ovaries from releasing an egg each month (ovulation) and/or to keep the cervical mucus thick so that sperms cannot easily pass through it.
    • Oral contraceptives are taken according to a prescribed daily schedule. Injectable contraceptives are given as intramuscular injection and prevent pregnancy for two or three months. Implants and vaginal rings, which are not readily available in South Africa, prevent pregnancy by delivering contraceptive hormones to the body from their site of application. Implants are small, rubber-like rods placed under the skin of the arm, while vaginal rings are placed into the vagina.
    • Hormonal methods require visiting a doctor for a prescription, injection, or placement of implants/rings.

    Oral contraceptives (the “pill”)

    • Available as combination of oestrogen and progestogen in dose regimens that suppress ovulation, or as progestogen-only pill that thickens the cervical mucus.
    • Highly effective if taken consistently, preferably at the same time each day. If a pill is missed or vomiting occurs soon after taking the pill, another form of contraception until the onset of the next menstrual period should be used.
    • Certain drugs may cause the pill to become less effective. This is the reason why a doctor needs to be consulted for the prescription. The doctor will ask about any medication used and will find out whether there are any contraindications for the pill.
    • An oestrogen containing pill can suppress or diminish milk production and is not advised to breast feeding mothers. The hormones are also excreted in the breast milk and can cause side-effects in the newborn baby.
    • If a woman wishes to have a baby, she should switch from the pill to another form of contraception (for example barrier method) three months before planning to conceive. The chance to fall pregnant soon is greater after discontinuing barrier methods than after stopping the pill.
    • Using the pill carries a slight health risk which increases with age and smoking. Oral contraception is usually not recommended for women over 45, or those over 35 who smoke. Women suffering from cardiac disease, thrombosis (blood clot formation in veins), breast cancer, tumours of the liver or endometrial carcinoma (cancer of the lining inside the womb) are also advised against the pill. A further, relative contraindication exists for women with poorly controlled diabetes, obesity or gall bladder problems.
    • Oral antibiotics may decrease effectiveness – a backup contraception method should be used while taking antibiotics until the next menstrual period following the completion of the antibiotic.
    • Women who experience unpleasant side-effects on one type of pill can usually adjust to another. When starting the pill, communication with the doctor needs to be maintained for optimal matching of the type of oral contraceptive.
    • Effectiveness:  If the combination pill is correctly used, the Pearl Index is less than 1.
    • Advantages
      • Very effective in preventing conception.
      • Is used independently from sexual intercourse.
      • Can make periods more regular.
      • Less: acne, iron deficiency anaemia, premenstrual tension, dysmenorrhoea (period pain), rheumatoid arthritis.
      • Reduces risk of: ovarian cancer, non-cancerous breast tumours (cysts, benign dysplasia). The stronger progestogenic pills have a protective effect against the development of endometrial (uterine) cancer.
      • Reduces risk of ectopic pregnancies. This potentially life-threatening condition occurs when the fertilised egg implants and begins developing outside the uterus – usually in the fallopian tubes.
      • Reduces risk of developing pelvic inflammatory disease (PID).
    • Disadvantages:
      Oestrogenic effects
      • Breast tenderness due to fluid retention. This improves after a few months.
      • Nausea. This also improves after a few months.
      • Vaginal candida infection. This used to be more common with pills having a higher oestrogen content.
      • Pigmentation in the face (chloasma). This is rare and improves after stopping the pill.

      Progestogenic effects

      • Acne or oily skin. This is due to progestogens with an androgenic (male-hormonal) effect.
      • Weight gain. Due to increased appetite caused by some progestogens.
      • Dyspareunia (painful sexual intercourse). Due to dryness of the vagina.
      • Headache. This may be due to progestogen withdrawal during the pill-free days.
      • Loss of libido (urge to be sexually active). This is very rare.

    The progestogen-only pill ('mini-pill')

    • Contains a progestogen and no oestrogen – alternative for women who desire contraception in pill form but are sensitive to oestrogen, or are breast feeding.
    • Should be taken daily like combined oral contraceptives but at exactly the same time each day.
    • Thickens the cervical mucus to prevent sperms from reaching the egg, changes the motility of the fallopian tubes to interfere with fertilisation, and makes the uterine lining less receptive for implantation should an egg become fertilised.
    • Effectiveness:  A Pearl Index of 2 which means a slightly higher risk for pregnancy compared to the combination pill.
    • Advantages
      • No oestrogen – suitable for those unable to take the combined pill because of adverse side-effects or personal medical history.
      • May decrease risk of endometrial cancer and PID.
      • Does not increase risk of heart disease (blood clots).
      • Women who are advised to stop taking the combined pill at a certain age (for example, if they smoke) can safely use the progestogen-only pill.
      • Can be used by diabetics – does not affect blood sugar levels.
      • Can be used during breast feeding – no effect on the baby or milk production. Together with the contraceptive effect of breast feeding, the prevention of pregnancy comes close to 100%.
      • No delay in future fertility – it is possible to become pregnant very soon after stopping this type of pill.
    • Disadvantages
      • Requires strict pill-taking routine: This pill needs to be taken at the same time each day and ideally not less than three hours before intercourse because it takes two hours for the pill to be effective on the cervical mucus.
      • Some women experience scanty, irregular periods.
      • Persistent spotting is another possible symptom, but this should resolve after a few months' usage or by switching brands.
      • Although the incidence of ectopic pregnancy is extremely low, the ectopic/intrauterine ratio is higher than with combined oral contraceptives or injectable progestogens.

    When to call a doctor:
    Women taking oral contraceptives should contact their doctor immediately when suffering any of the following conditions:

    • Severe or sudden onset of abnormal bleeding
    • Severe headaches
    • Sharp, stabbing pains in the chest
    • Blood present in sputum
    • Blurred vision
    • Muscle weakness
    • Severe abdominal cramping

    Injectable contraception

    • Progestogen injection deep into muscular tissue of buttocks or upper arm.
    • Although similar to the 'progestogen-only pill' regarding the effect on cervical mucus, tubal motility and endometrium, the additional effect of the injectables is inhibition of ovulation due to the larger dose of progestogen.
    • Single injection provides contraceptive protection either for 12 weeks (Depo- Provera®, Petogen®) or for 8 weeks (Nur-Isterate®).
    • Benefits similar to mini-pill. Side-effects are also similar and can include irregular periods, weight gain, and breast tenderness. Most women develop amenorrhoea (no periods) and need to be adequately informed about this beforehand.
    • Advantages:
      • Extremely effective (99%) as long as injection is repeated at the correct intervals.
      • Allows contraception independent of sexual intercourse.
      • Does not depend on high level of user compliance.
      • Prevents ovulation – reduces risk of ectopic pregnancies.
      • Reduces risk of ovarian cysts.
      • Can be safely used while breast feeding.
      • No oestrogen-related side-effects – mainly benefits women unable to take oestrogen, or those over the age 35 who smoke.
      • No effect on blood pressure and clotting. Does not contribute towards developing thrombosis, and may be used under medical supervision by patients with hypertension, previous thromboembolism, cardiac disease, diabetes and obesity.
    • Disadvantages
      • Longterm side-effects. Women who suffer side-effects may need to endure them for the duration of the contraceptive's action.  
      • Several women may gain weight when first using this method, although this usually stabilises.
      • Effectiveness may be impaired by certain medication (anticonvulsants, rifampicin, meprobamate) and also by alcohol. The doctor may advise to shorten the interval between injections.    
      • Becoming pregnant could be delayed by six months to a year after stopping the injectable. It should not be the first choice of contraception if a pregnancy is planned fairly soon.
      • Can cause menstrual irregularities which can be treated with oestrogen containing tablets.
      • Painful intercourse may occur because of a dry vagina which can be treated with oestrogen cream.


    None of the implants are available in South Africa at present. Norplant®, which was available for a short time and then withdrawn from the market, consisted of  3 cm long silastic rods which were surgically implanted under the skin of the upper arm. Six rods protected against pregnancy for up to five years by steadily releasing  a contraceptive hormone (levonorgestrel).  A newer single-rod device (Implanon®) may become available containing  a contraceptive hormone (3-keto-desogestrel) which is slowly released over three years.

    • Advantages
      • Highly effective, reversible contraception.
      • Needs to be administered only after long intervals (three and five years).
      • Does not depend on high level of user compliance.
      • Return of fertility is quick after removal of implant.
      • Financial cost may be less than buying oral contraceptives every month over the same time period.
    • Disadvantages
      • Insertion requires a small surgical procedure under local analgesia by a skilled health professional trained in the technique.
      • May cause irregular bleeding.
      • Possible removal problems.

    Emergency contraception

    • Every woman should be aware of this method for an emergency situation (rape, incest, failed contraception: broken condom, missed pill).
    • Emergency contraception aims to prevent pregnancy after unprotected intercourse has taken place. It is also referred to as postcoital contraception or “morning-after pill”.
    • Oral emergency contraception must be administered within 72 hours of unprotected intercourse and is available in two forms:
    1. Oestrogen-progestogen regimen
    2. Progestogen-only regimen
    • The oestrogen-progestogen treatment regimen consists of  two Ovral® tablets 12 hourly for two doses, starting as soon after unprotected sex as possible, and not later than 72 hours.
    • Another product, registered for emergency contraception, is E-gen-C® containing four tablets of ethinylestradiol and levonorgestrel. The first dose is two tablets, followed by the other two tablets 12 hours later.
    • An antiemetic drug can be taken before each oestrogen-progestogen treatment regimen for the prevention of nausea and vomiting. If vomiting occurs within two hours of the first dosage, it could diminish the effectiveness of oral emergency contraception and another two hormonal pills should be taken.
    • The progestogen-only treatment regimen consists of a total dose of 0.75 mg levonorgestrel to be taken immediately and to be repeated 12 hours later. A product (Norlevo®), licensed for emergency contraception in this dosage, is available in South Africa.
    • An alternative method for the progestogen-only regimen is taking 25 pills Microval® on two occasions with a 12 hour interval.
    • The progestogen-only regimen is more effective than the combined pill regimen and has a lower incidence of nausea and vomiting.
    • It does not help to swallow any extra pills for emergency contraception than those prescribed. More pills will probably not decrease the risk of pregnancy any further, but will increase the risk of nausea.
    • If the time interval has exceeded 72 hours or oral contraceptives are contraindicated or the patient suffered from severe vomiting, a copper containing IUD may be inserted into the uterus for a time of up to 120 hours after unprotected sex. The IUD has the advantage of providing ongoing contraception.
    • Following emergency contraception. the next period may start a few days earlier or later than usual. If the period does not start within four weeks, the doctor or clinic should be attended again for an examination and a pregnancy test.
    • Emergency contraception should not be used as a replacement for ongoing birth control, because of ongoing birth control's higher efficacy and lesser side-effects.

    Reviewed by Dr P.S. Steyn and Dr P. Roets, Tygerberg Hospital and Stellenbosch University