Barrier Methods of Contraception

Abstract

Barrier methods of contraception prevent the exchange of bodily fluids such as semen, vaginal and anal secretions, and blood between partners during intercourse. Thus, the primary function of these methods of contraception is pregnancy prevention. Some, such as internal and external condoms, provide protection against sexually transmitted infections (STIs) as well. Barrier methods of contraception include condoms (external and internal), diaphragm, cervical cap, contraceptive gel, spermicide, and contraceptive sponge. Since they are non-hormonal and have no systemic effects, these are alternatives for women who cannot use hormonal contraceptives due to certain medical conditions or medications prescribed. The efficacy of these methods of contraception is contingent on their correct and consistent use. This chapter aims to discuss the various barrier methods, their usage, mechanisms of action, advantages, and disadvantages as well as the comparison of some of these methods to one another.

1. Introduction

Contraception has been around for some centuries now. Using various techniques to prevent pregnancy, ancient writings dating back to 1850 BC recorded the insertion of various substances into the vagina. Substances such as crocodile dung, gum, honey, and acacia were used. At that time, it was believed that these substances created a hostile environment for sperm to survive [1]. Another well-known method dating back to centuries which is still being used is coitus interruptus (withdrawal method). The effectiveness of withdrawal is dependent on timing, self-control, and apt removal of the penis before ejaculating. Due to the high failure rates of this method, other methods had to be devised to address contraception [2]. As medicine extended its tentacles to address contraception, the main points of focus were efficiency, efficacy, mechanism of action, and the failure rates of each device and pill created.

Contraception can be classified into barrier and non-barrier methods. Barrier methods act as blockages that prevent sperms from reaching the egg [1]. Barrier methods of contraception which are the focus of this chapter have been recognized many centuries ago. As early as the 18th and 19th centuries, items such as leaves, sponges, and lemons were used to block sperm from entering the uterus [3]. For instance, some ancient Egyptian arts display men with decorative coverings of their penises [3]. Just like the withdrawal method which has a high failure rate, these barrier methods were to some extent unreliable because of their fragility, nature, and low to no proficiency rate. Over time, barrier methods including spermicides, condoms, diaphragms, cervical caps, and contraceptive gels and sponges were discovered. The game changer for barrier methods to be unleashed was when rubber was discovered in 1839 by Hancock and Goodyear [3]. With this discovery, many of the barrier methods from the 19th century up until now were made of rubber which made them inexpensive and easily accessible to many. On a wide scale, even though barrier methods can interrupt pregnancy, most are not effective in protecting against sexually transmitted diseases.

The vast types of barrier methods give an individual many options to birth control depending on the conduciveness of lifestyle, accessibility, risk, consistency, and usage. Other factors to consider in selecting a barrier method include allergies, bouts of sexual encounters, duration, and frequency of the device’s usage. Some barrier methods require a physician’s discretion while others can be purchased over the counter. Even in some cases, the efficiency of contraception can be achieved by the combination of various barrier methods. Advantageously over non-barrier methods, barrier methods can be used intermittently and possibly overcome systemic side effects [1]. In this book chapter, we will discuss the various barrier methods, their mechanism of action, efficacy, advantages, and disadvantages.

2. External (male) condoms

2.1 Introduction

It is a thin protective sheath worn over an erect penis during intercourse [4]. External condoms reduce the likelihood of unintended pregnancy and transmission of sexually transmitted infections (STIs) when used correctly and during every sexual activity [4].

2.2 Types of external condoms

External condoms are made from various materials and come in different shapes, sizes, thicknesses, colors, flavors, and with or without reservoir tips that collect semen. They may or may not contain lubricants or spermicides [5, 6].

2.2.1 Latex condoms

Most condoms manufactured commercially are made of latex. They are less expensive and have higher tensile strength than non-latex condoms. Latex condoms are more effective than non-latex condoms at protecting against all common types of STIs with correct and consistent use [7]. Although the advantages of latex have made it the most preferred material for condoms, it has a few drawbacks. Latex condoms can trigger an allergic reaction in people who are allergic to latex [1, 4, 8] and are degraded by oil-based lubricants; therefore, they should not be used in conjunction with oil-based lubricants [1, 4, 9].

2.2.2 Non-latex condoms

Non-latex condoms can be made from lambskin and synthetic materials such as polyurethane, silicone, or polyisoprene [1, 4]. Non-latex condoms are an alternative for individuals who are allergic to latex [1, 4, 8]. Polyurethane condoms do not stretch like latex or polyisoprene, making them more susceptible to slippage and breakage. Polyurethane condoms are thinner and conduct heat better than latex and polyisoprene which may enhance sensitivity. Polyurethane condoms can be used with both water-based and oil-based lubricants. In contrast to polyurethane condoms, polyisoprene condoms are cheaper, stretchier, thicker, conduct heat poorly, and are incompatible with oil-based lubricants [1]. Lambskin condoms are manufactured from the intestine of a lamb and are not as common as the other external condoms [1, 4, 8], and can be used with any type of lubricant [6]. Because of their porous nature, viruses such as HIV, hepatitis, and herpes simplex as well as bacteria such as gonorrhea can easily pass through; thus, they do not offer protection against STIs. They are only effective for preventing pregnancy [1, 4, 8].

2.3 Mechanism of action

It functions by creating a physical barrier that prevents the entry of semen into the vagina. Also, it prevents direct contact with genital lesions, secretions from the penis, vagina, anus, and subclinical viral shedding on the genitals. Thus, pregnancy as well as STIs like HIV can be prevented [4, 5].

2.4 How to put on and remove an external condom

• For every sexual encounter, a new condom should be used [4, 7].

• Always use the right condom size.

• Before you open the package, inspect it, and check the expiration date. Do not use it if it is expired, torn, or damaged.

• Carefully open one end of the condom package. Avoid using your teeth or objects that can tear the condom.

• With the rolled side of the condom out, place the condom on the tip of the erect penis and leave about 1/2 inch space at the top to collect semen.

• Pinch the tip of the condom with one hand to get rid of trapped air.

• With the other hand, unroll the condom to fully cover the shaft of the erect penis.

• After ejaculation, make sure you withdraw the penis from the other partner’s body while it is still erect to prevent spillage of semen. Hold the rim of the condom when withdrawing the penis.

• Remove the condom, wrap it in tissue or plastic bag and dispose of it in a bin.

2.5 Efficacy

The most important factor in determining the efficacy of condom use is correct and consistent use [4, 8]. External condoms are highly efficacious in pregnancy prevention, with just about 2% of women becoming pregnant within the first year of perfect use of condoms and approximately 13% being pregnant within the first year of typical use [4, 10]. Perfect use of condoms refers to correct and consistent usage while typical use refers to the way most people use them [11]. With correct and consistent usage, external condoms are estimated to be 80–95% effective in preventing the spread of HIV and other STIs [4].

2.6 Advantages

• External condoms are safe to use with no systemic side effects.

• They provide effective protection against STIs, including HIV by acting as a physical barrier that prevents the exchange of bodily fluids [4].

• They are easy to use and do not require special training or skills.

• They are widely available to individuals without a prescription. They can be obtained from pharmacies, clinics, supermarkets, convenience stores and gas stations [6, 12].

• They are relatively inexpensive, and even freely distributed at condom distribution programmes [6].

• They are reversible methods of contraception that do not interfere with fertility for both partners [4].

• For some men, wearing thicker condoms can help prevent premature ejaculation by reducing sensitivity in the penis and improving penile erection [13].

2.7 Disadvantages

• The use of regular condoms is a challenge for individuals who are allergic to latex. Non-latex condoms are relatively expensive and not as effective as latex condoms.

• Concerns about reduced sensitivity during sexual intercourse are frequently expressed by couples who use condoms [6, 12].

• Some users have difficulty maintaining an erection while wearing condoms [6].

• It can be difficult to withdraw the penis from the vagina before it becomes flaccid after ejaculation, which can cause condom slippage and semen discharge into the vagina [12].

• Condoms can tear or break during intercourse and may result in an unwanted pregnancy or exposure to STIs. Some of the factors associated with condom breakage are excessive friction during sex, longer duration of intercourse, incorrect usage, using the wrong size, use of oil-based lubricants, and reuse of condoms [9, 13, 14]. Oil-based lubricants can impair the integrity of latex condoms [9].

3. Internal (female) condoms

3.1 Introduction

Internal condoms are the only female-controlled contraceptive method that has been proven to reduce the likelihood of both unintended pregnancy as well as transmission of sexually transmitted infections (STIs). It is a tool for empowering women as it bolsters their sexual confidence and offers them more control over their reproductive health.

Typically, an internal condom consists of a soft sheath and two flexible rings. The closed end of the sheath has an inner ring which is inserted vaginally. An outer ring at the open end lies outside the vagina after insertion [15]. It is intended for only one-time use. In contrast to external condoms, internal condoms can be inserted at any time up to 8 hours prior to intercourse [4]. Note: Internal and external condoms should not be used concurrently, as friction between the two can result in slippage or tearing [4].

3.2 Types of internal condoms

3.2.1 Polyurethane condoms (FC1)

FC1, which is no longer commercially available, was made of Polyurethane. They were the first generation of internal condoms that was approved by the United States Food and Drug Administration (USFDA) in 1993 [15]. However, polyurethane condoms have been replaced by newer versions of female condoms that are less expensive and have high acceptance rates. Although internal condoms available on the market today differ in designs and materials, they have many functional and structural similarities [15]. It was approximately 17 cm long and pre-lubricated with dimethicone, a silicone-based lubricant [15].

3.2.2 FC2

The Femidom female condom (FC2), which replaced the FC1, is just as efficacious as its predecessor but is made of nitrile and does not have a seam. It makes less noise than FC1 during intercourse [15]. It is pre-lubricated with a silicone-based lubricant on both the interior and exterior. It is the only commercially available internal condom approved by the FDA. It has received CE marking and approval by the WHO [16]. Studies comparing FC2 and FC1 found that the FC2 was on par with the FC1 in terms of patient’s acceptability, breakage, slippage, and invagination but sold at a lower price [15, 17].

3.2.3 VA w.o.w (worn of women)

L’amour, Condom Feminine, and Reddy FC are some of the brand names under which it is sold. It is made of latex, just like external condoms. Its unique design features a medical-grade sponge anchored to its closed end for insertion and a triangular frame at the open end which lies outside the vagina. It has received CE Marking and is currently being evaluated by the WHO [ 16, 17].

3.2.4 The Woman’s condom

The PATH (Program for Appropriate Technology in Health) Women’s condom is manufactured with polyurethane and has an insertion capsule that dissolves inside the vagina. It is not pre-lubricated; rather, a water-based lubricant is included in the package that the user must apply. The presence of hydrophilic areas on the condom allows it to adhere lightly to the walls of the vagina, which keeps the condom in place [16, 17]. Data from a single-arm study carried out in China to evaluate the performance of WC in terms of function and safety, were consistent with data already available on the effectiveness of the other internal condoms, indicating that the WC performs as well as the other internal condoms [18]. It has CE marking and is currently under review by the WHO [16].

3.2.5 Phoenurse (PFC)

It is a polyurethane condom that comes pre-lubricated with a water or silicone-based lubricant and has an insertion tool attached to the inner ring [15, 19]. It is only distributed in China, [15, 19, 20] and received approval from the China State Food and Drug Administration (CFDA) only [15, 19]. In a randomized control trial conducted in China, FC2 was preferred over PFC in terms of lubrication, color, and overall fit [21]. Another study conducted in China revealed that breakage, misdirection of the penis, and slippage were significantly more common with the PFC than with the FC2 [22]. It has received only CE marking [16].

3.2.6 Natural latex female condom (cupid FC and cupid FC2)

It is made of natural latex and pre-lubricated with a silicone-based lubricant. It also has a medical-grade polyurethane sponge attached to the inner ring for insertion and stability and has an octagonal outer ring. The only differences between Cupid2 and Cupid® are that Cupid2 is a bit shorter and has a smaller sponge [19]. In a randomized noninferiority clinical trial, Cupid2 and FC2 had similar clinical failure rates in terms of invagination, clinical breakage, penile misdirection, and slippage [23]. It has received CE marking and approval by the WHO [16].

3.2.7 Panty female condoms

It is composed of a reusable nylon woman’s panty and a condom sheath. The panty serves as the outer ring and secures the condom sheath during intercourse. The condom sheath must be replaced following each use. A pilot study conducted in South Africa revealed that, the clinical failure rate of the Panty Condom in terms of clinical breakage, misdirection, slippage, and invagination was about twice that seen in functionality studies of the other internal condoms [24].

3.3 Mechanism of action

Internal condoms are sheaths that line the vagina acting as physical barriers that prevent the introduction of sperms directly into the female reproductive tract, thereby preventing pregnancy. Also, they prevent the transmission of sexually transmitted infections by preventing the exchange of genital secretions [4].

3.4 How to put on an internal condom

1. For every sexual intercourse, a new condom should be used.

2. Inspect the package and check the expiration date. If it is expired, torn, or damaged, do not use it.

3. Wash your hands and carefully open one end of the condom. Avoid using your teeth, fingernails, or objects that can damage the condom.

4. When inserting the condom, you can squat, lie down, or sit.

5. Squeeze the inner ring of the condom with your thumb and index finger and insert it into the vagina. Push it deep with one finger until it rests against the cervix while ensuring that the condom is not twisted. The outer ring should lie outside the vagina.

6. Direct the penis into the opening of the condom. If the penis slips between the condom and the vaginal wall, you must withdraw and try again, or if the outer ring is pushed into the vagina, re-adjust the ring, and try again.

7. After intercourse, hold the outer ring and gently twist it to prevent the semen from spilling out, and then gently pull the condom out of the vagina.

8. Wrap the used condom in tissue or plastic bag and throw it into a bin. Do not reuse [4].

3.5 Efficacy

During the first year of using internal condoms, approximately 5% of women will get pregnant with perfect use and about 21% of women will get pregnant with typical use [4]. These estimated failure rates are from studies conducted on the efficacy of FC1. Currently, there is no specific data on FC2 condoms’ ability to prevent pregnancy and STIs. Since the FC2 condom shares many characteristics with the FC1 condom, including its functionality and design, its effectiveness in preventing pregnancy and STIs is assumed to be comparable to that of the FC1 [15, 19]. Although in vitro studies have suggested that internal condoms are impermeable to HIV and other STIs, there are limited clinical studies that have evaluated the internal condom’s ability to prevent HIV transmission.

3.6 Advantages

• Internal condoms are non-hormonal therefore they do not have systemic side effects or interfere with medications. As a result, they are an alternative for individuals with contraindications to hormonal contraceptives.

• Some internal condoms are latex-free and can be used by individuals with latex allergy.

• It is a simple and reversible method of contraception that does not cause a delay in the return of fertility when the method is discontinued.

• It is safe to use while breastfeeding.

• Internal condoms are available over the counter.

• It can be worn up to 8 hours before sex therefore there’s no need to rush which can kill the mood.

• The external ring may stimulate the clitoris in some women during intercourse, thus enhancing sexual arousal.

• It provides effective protection against pregnancy and STIs as it offers broader coverage of the external genitalia [4, 12].

3.7 Disadvantages

• Internal condoms can be a bit difficult to insert and remove for some women.

• Feeling of discomfort during insertion

• It may slip into the vagina during intercourse and interfere with the spontaneity of sexual experience.

• It can make unpleasant noise during intercourse.

• It is generally more expensive and not widely available as external condoms.

• It has a higher failure rate in preventing pregnancy compared with most other female contraceptive methods and the external condom.

• Internal condoms are not as widely available as external condoms.

• Internal condoms have lower acceptance rates due to factors such as feeling of discomfort during insertion, rejection by the opposite sex, misconception of effectiveness and high cost.

3.8 Internal condoms vs. external condoms

• Internal condoms can be worn for up to 8 hours prior to intercourse while external condoms are only worn just before initiating intercourse.

• One does not require an erection to put on an internal condom; it can be inserted vaginally or anally while external condoms can only be worn over an erected penis.

• Internal condoms are not as widely available as external condoms.

• Internal condoms have higher failure rates compared to external condoms.

4. Diaphragms

4.1 Introduction

Diaphragms are shallow silicone dome-shaped cups with a flexible rim that are inserted into the vagina to cover the cervix. Diaphragms are reusable for up to two years and are available in various sizes– single-size and multisize. The single-size diaphragm, also known as the Caya diaphragm, is the standard and measures about 75 mm long by 67 mm wide. It does not require traditional fitting by a healthcare provider [4, 25]. Instructions are easily applicable by the user. Multisided diaphragms are diaphragm-fitting kit that is used by the clinician to figure out which best fits the woman’s anatomy and to educate patients on how to insert and remove the device without complications [4, 25]. Notably, diaphragms are often used with contraceptive gels to increase its efficacy. Usually used with a spermicide, it provides both a chemical and physical barrier to the sperm. Males condoms can be used at the same time a woman uses a diaphragm to increase contraceptive effectiveness and accuracy.

4.2 Mechanism of action

The diaphragm works by covering the cervix, therefore, preventing sperms from getting through the cervix to the uterus. With the combination of the contraceptive gel or spermicide, the sperms are held back by the shallow silicone-shaped dome in the cervix, and the sperms are killed by the spermicide. The diaphragm consists of little bumps on the outer layer which help grip the device around the cervix and for easier insertion into the vagina with a grip or a squeeze [4, 25].

4.3 How it is used

A woman can learn to use a diaphragm herself. It is simple to insert without any complications.

• First, the user washes her hands thoroughly with soap and water.

• Checks the diaphragm for any damages such as holes, tears or cracks each time she uses the device.

• Check the expiration date of the spermicide, water lubricant, or contraceptive gel to avoid using an expired product.

• The user pinches the diaphragm together with both her thumb and index finger; then places a line of contraceptive gel in each fold and slightly on the front rim to enable easy insertion into the vagina without friction.

• The user chooses a comfortable position such as lying down, standing with one leg up, or squatting.

• The device is inserted with the front rim first in the direction of the tailbone by pushing it all the way in as her finger can reach. Then she pushes the front edge up to tuck it behind her pubic bone. If she does not aim the diaphragm toward her tailbone, it will not be in the right place.

• To be sure the diaphragm is correctly fixed, she can feel her cervix with her finger to be sure that the cervix is completely covered by the diaphragm.

• If the position of the diaphragm feels uncomfortable, she can take it out and reinsert it.

• Note, the diaphragm should remain in the vagina for at least 6 hours after having coitus but not more than 24 hours [4].

• For multiple coital acts, the diaphragm should be in the right position and additional spermicide should be inserted in front of the diaphragm before having sex.

• Leaving the diaphragm in place for more than 24 hours can cause bad odor, unusual vaginal discharge, urinary tract infections, and toxic shock syndrome.

• If the diaphragm is too large, the user may not be able to insert it completely which may feel uncomfortable. If it is too small, it may not completely cover up the cervix.

• Women who just had a baby will have to wait for 6 weeks before they can use this device [4, 26].

4.3.1 To remove the diaphragm

• Wash your hands thoroughly with soap and water.

• Insert a finger into the vagina until the rim of the diaphragm is felt.

• Calmly slide a finger under the rim and pull the diaphragm down and out.

• Wash the diaphragm with soap and water, air dry the device in its open case at room temperature and store it for later use. This device can be used for up to 2 years [4].

4.4 Efficacy

With consistent and correct use together with spermicide, the failure rate for typical use is 12% and that for perfect use is 6%. In comparison to other contraceptive methods such as cervical cap and contraceptive sponge, the diaphragm is more effective and can be used for a longer time (up to 2 years) [25, 27].

4.5 Advantages

• Diaphragms can be inserted ahead of time. In due process, the woman can prepare well before any sexual encounter with less stress and surprises. Also, with the ample time to utilize the device (inserted at least 6 hours but removed before 24 hours), the partners can use the device with multiple bouts of sexual encounters in the day.

• It can be reused for up to 2 years.

• After the initial purchase of the diaphragm and its accessories, the only expense left is replacing the spermicide.

• After education and fitting instruction are conveyed by a health professional, there is no need for periodic visits to the clinic for evaluation up until 2 years. It saves time and money.

• Diaphragms do not cause systemic adverse effects. Unlike other contraceptives such as oral contraceptives and implants, diaphragms do not affect the hormonal balance of the user [4, 25, 28].

4.6 Disadvantages

• Just like some contraceptives that need a prescription and education from a licensed health provider, diaphragms are no different. Individuals without access to a clinic or a health professional cannot get this device [4, 25].

• Considered to have a lower efficacy rate compared to other contraceptives such as intrauterine devices such as progestin which have an efficacy rate of 99% [29].

• There are also side effects and complications such as urinary tract infections (UTI), vaginal irritations, and toxic shock.

  syndrome (TSS).

5. Cervical cap

5.1 Introduction

The cervical cap is a reusable silicone cup shaped like a sailor’s hat. It is inserted into the vagina before coitus with the dome-shaped area of the cap covering the cervix. Usually, a cervical cap is used with a spermicide to boost its efficacy [4, 28]. The spermicide increases contraception by killing the sperms that come into contact with the cervical cap and reduces the fetid discharge brought on by the continuous use of the cervical cap [4].

5.2 Mechanism of action

The cervical cap fits snugly over the cervix, preventing sperm from entering the uterus. Similar to the mechanism of the diaphragm, the cervical cap blocks the sperm from entering the cervix and the spermicide in the dome kills the sperms. It provides both physical and chemical barriers at the entrance of the cervix.

5.3 To insert a cervical cap

• Wash your hands thoroughly with soap and water.

• Apply one-third of the cap with spermicidal cream to the dome of the cap up to the brim.

• Apply an additional 1/2 teaspoon of spermicide in the groove between the outside of the dome and the brim.

• Choose a comfortable position for insertion. You can decide to lie down, stand with one foot on a chair or squat.

• Locate the cervix using your index and middle finger by placing both in the vagina.

• Firmly press the cervical cap with the dome pointing away from the vagina.

• With one or two fingers, slide the longer part of the brim into the vagina making sure the cervix is completely covered by the cap.

• Leave the cap for up to 48 hours [30].

5.3.1 Remove cervical cap

• Wash your hands thoroughly with soap and water.

• Wait up to 6 hours after sex before removing the cap.

• Squat and slide a finger into the vagina to locate the strap that covers the dome [25].

• Use the tip of your finger to slowly push the dome to break the suction [25].

• Gently pull down on the strap to remove the cap from the vagina.

• With soap and water, wash the cap with soap, and water and let it air dry.

5.4 Efficacy

Women who are nulliparous or who have never given birth vaginally respond best to the cervical cap as a method of contraception. Out of 100 women who will become pregnant with typical use of the cervical cap, only about 13% are nulliparous and about 32% are multiparous. Since the sizes of the cervix alter because of pregnancy and abortion, the small size (22 mm) is usually for patients who have not been pregnant before, while the medium size (26 mm) is for patients who have had an abortion or cesarean delivery and large size (30 mm) for users who have had full term delivery vaginally [25].

5.5 Advantages

• It can be inserted 6 hours before having intercourse, so the woman can prepare adequately.

• It is easily reversible when insertion is uncomfortable.

• It is affordable and can be used for up to 2 years [25, 29].

5.6 Disadvantages

• It is required with every act of intercourse.

• Provides no protection against STIs.

• Has difficult learning insertion and removal instructions.

• Cervical cap cannot be used [31]:

• 8–10 weeks after giving birth.

• 6 weeks after miscarriage or abortion because at that point the cervix is enlarged so it is easier to become pregnant.

• During a menstrual period because it can block normal drainage of blood from the uterus.

5.7 Differences associated with diaphragm and cervix

Cervical caps are smaller than diaphragms, so therefore they fit snugly on the cervix.

Cervical caps can be used for up to 48 hours while diaphragms can be used for 24 hours.

Cervical caps are more expensive than diaphragms.

6. pH regulator contraceptive gel

6.1 Introduction

The contraceptive gel is a formulation that contains lactic acid (18 mg/g), citric acid (10 mg/g), and potassium bitartrate (4 mg/g) as active ingredients. It is marketed under the brand name Phexxi (previously on the market as Amphora and ACIDFORM). It comes in 12 pre-filled applicators, each containing 5 grams of gel, and is available by prescription only. It provides on-demand contraception when used prior to intercourse. It was approved for contraceptive use in 2020. It works better when used in conjunction with other barrier methods like condoms, diaphragms, and cervical caps [29, 30, 31, 32, 33, 34].

6.2 Mechanism of action

It works by lowering the pH of the vagina to between 3.5 and 4.5 even in the presence of alkaline semen, creating a more acidic environment that affects the viability and motility of sperms thus preventing fertilization [35].

6.3 How it is used

• Inspect the package and check the expiration date. Do not use it if it is expired or the seal is broken.

• Ensure that you read and follow the instructions on the package carefully.

• Wash your hands thoroughly before opening the pouch.

• Apply one dose into the vagina with the applicator no more than 1 hour prior to intercourse.

• Reapply one dose of gel before each coital act. If there’s more than one coital act within an hour, it is recommended to administer a second dose for increased efficacy. Reapplication is necessary if intercourse does not occur within an hour.

• Dispose of the used pre-filled applicator [34, 36]

• Note: It is not effective when used after intercourse.

6.4 Efficacy

The estimated failure rates are 7% within the first year of perfect use and 14% within the first year of typical use. It does not provide users with protection against sexually transmitted infections [7, 35, 37].

6.5 Advantages

• It is non-hormonal.

• It can be applied up to one hour before sex, therefore, it does not interrupt foreplay.

• It can be applied during the menstrual cycle.

6.6 Disadvantages and side effects

• It does not offer protection against STIs.

• Common side effects such as vulvovaginal burning, vulvovaginal itching, vulvovaginal pain, bacterial vaginosis, urinary tract infections, and vaginal yeast infections (candidiasis) were experienced by about 2% of participants in phase 3 of a clinical trial conducted in the United States and were reported to be mild or moderate [36]. Major side effects such as pyelonephritis, cystitis or other upper urinary tract infections were experienced by 0.36% of the participants in phases 1 and 2 of the clinical trial [34].

• In a clinical trial, spouses of participants reported penile irritation [3, 36]

6.7 Contraindications

• It should not be used by women who have a history of recurrent urinary tract infections or urinary tract anomalies [34, 37].

• It is not recommended during pregnancy. According to the FDA, the risk for miscarriage is 15–20% and major birth defects is 2–4% [34].

7. Spermicides

7.1 Introduction

Spermicidal contraceptives contain a spermicidal agent and a carrier. The active ingredient commonly used is nonoxynol-9 which is a surfactant. Currently, nonoxynol-9 and octoxynol-9 are the only FDA-approved spermicidal agents. Spermicidal contraceptives come in a variety of formulations such as gels, creams, jellies, foaming tablets, suppositories, films, and sponges. They can be used alone or combined with condoms, diaphragms, and cervical caps for increased efficacy. They are only effective when utilized prior to intercourse, and are available over the counter [4, 25].

7.2 Mechanism of action

Nonoxynol-9 in spermicidal products damages the cell wall of sperms, impeding their transit from the vagina to the uterus [25].

7.3 How they are used

• Inspect the package and check the expiration date. Do not use it if the package is broken or expired.

• Ensure you have read and understood the instructions on the package.

• Hands must be washed thoroughly with soap under running water.

• Vaginal spermicidal gel and creams can be inserted up to one hour before intercourse.

• It is necessary to insert suppositories, films, and tablets at least 10 minutes before sexual activity to give them enough time to dissolve.

• When using spermicidal foams, you do not have to wait for 10 minutes before having intercourse.

• Reapply the spermicide before each act of intercourse.

• Douching must be avoided since it will affect the efficacy of spermicides and increases the user’s risk of contracting STIs.

• Wait for at least six hours after having sex if you want to douche [4, 25].

7.4 Efficacy

Spermicide is one of the least effective means of contraception. For spermicides such as foam, gel, cream, film, suppository, tablets, and jelly, the estimated failure rates with typical use and perfect use are 21% and 16% respectively. Spermicides are ineffective in preventing the transmission of sexually transmitted infections [4].

7.5 Advantages

• They are non-hormonal.

• They are available over the counter.

• They can be easily applied by the user.

• They can be used ahead of time and so do not interfere with foreplay.

• They provide extra lubrication.

• Their use is controlled by women [4, 25].

7.6 Disadvantages

• They do not protect against STIs.

• They have high failure rates therefore must be combined with other barrier methods.

• Side effects such as vaginal and penile irritation.

• Frequent use can cause vaginal lesions which may increase one’s risk of HIV infection [4].

7.7 Contraindications

• Women who are allergic to nonoxynol-9.

• HIV-positive women

• Women at high risk of exposure to sexually transmitted infections (STIs) [4, 25].

How does pH contraceptive gel differ from spermicide?

pH contraceptive gel does not contain nonoxynol-9 (N-9) which is the active ingredient in spermicide. N-9 can cause disruption of the epithelial cells of the vagina when used repeatedly which may enhance HIV transmission in high-risk individuals [33, 34].

8. Contraceptive sponge

8.1 Introduction

It is a polyurethane sponge that contains a nonoxynol-9 spermicidal agent and is marketed under the brand name Today sponge. It is available over the counter and does not require to be fitted by a health professional [38].

8.2 Mechanism of action

In addition to the effect nonoxynol-9 has on sperms, the sponge blocks the opening of the cervix and absorbs semen thus preventing the entry of sperms into the uterus [38].

8.3 How it is used

• Inspect the package and check the expiration date. Do not use it if the package is broken or expired.

• Hands must be washed thoroughly with soap under running water.

• Remove the sponge from the package.

• Wet the sponge with clean water and gently squeeze it until it is sudsy. The spermicide becomes only activated when moistened.

• Choose a comfortable position for insertion (squat, lie down, or sit)

• With the dimpled side facing upwards, fold the sides of the sponge inward toward the dimple and insert it and push it as far back into the vagina.

• Ensure the sponge is well positioned by feeling around the outline of the sponge with a finger.

• The sponge can be left in the vagina for up to 24 hours, providing protection throughout that time frame regardless of the number of times the user has.

• The sponge should be left in the vagina for 6 hours after the last coital act before removing.

• The sponge must not be kept in the vagina for longer than 30 hours [38].

8.4 Efficacy

For nulliparous women and multiparous women, the typical use failure rates are 12% and 24%, respectively. It does not offer the user protection against sexually transmitted infections [25, 27].

8.5 Advantages

• It provides 24-hour protection without having the need to replace it following multiple bouts of coitus.

• It is available over the counter and does not require fitting by a health professional.

• It allows spontaneity.

• It is safe and easy to use.

• They provide extra lubrication [38].

8.6 Disadvantages

• Side effects such as vaginal irritation and dryness are commonly experienced.

• The incidence of nonmenstrual toxic shock syndrome has been reported although it is rare [38].

8.7 Contraindications

• Women who have had toxic shock syndrome in the past.

• Those who are allergic to sulphites since the product contains metabisulphite.

• If you or your partner has HIV/AIDS

• Women with a history of an allergic reaction to polyurethane, nonoxynol 9, or this product.

• It cannot be used during the menstrual cycle [38].

9. Conclusion

Barrier methods of contraception are the most effective coitus-dependent contraceptive method for preventing unintended pregnancies and STIs. There are a variety of options with varying levels of efficacy from which one can choose from based on one’s preferences and lifestyle. Consistent and correct use are crucial to maximizing their effectiveness irrespective of the method chosen. In contrast to hormonal contraceptives, barrier methods do not cause systemic side effects, therefore they are especially suitable for women with medical conditions that preclude the use of hormonal contraception.

Conflict of interest

None.