Reproductive planning for women after solid-organ transplant
ABSTRACT
Women who receive transplants require contraception counseling because of the teratogenicity of immunosuppressant medications and the risks posed by pregnancy after transplant. Fortunately, pregnancy can succeed with careful planning and monitoring.
KEY POINTS
- The number of solid-organ transplants in US women of childbearing age has increased over the past 20 years.
- Women should wait at least 1 year after receiving a solid-organ transplant before attempting to become pregnant, and then should do so only when cleared by the transplant team and obstetrician, with close monitoring.
- The various types of contraception can be grouped by their effectiveness and by the medical eligibility criteria set by the US Centers for Disease Control and Prevention.
- Transplant recipients of childbearing age should use 2 contraceptive methods concurrently, one of which should be condoms.
Combined hormonal contraceptives
Combined hormonal contraceptives contain both estrogen and progesterone and are available as pills, patches, or rings. Each product has an unintended pregnancy risk of 9% with typical use and less than 1% with correct use.23 They require strict patient adherence to regular daily use, which likely explains their high failure rate with typical use.
Combined hormonal contraceptives reduce mortality risk in women in the general population,37 but their effect on mortality risk after transplant is unknown and needs further study. In women who received liver transplants, low-dose combined hormonal contraceptives have been found to be effective and well tolerated, but initiation should be delayed at least 6 months until postoperative organ stability is demonstrated.11
Combined oral contraceptives are the most widely prescribed because they are convenient and familiar and have an acceptable safety profile in transplant patients,11,33,37 despite their high failure rate with typical use. They regulate the menstrual cycle and reduce anemia associated with menstruation.
The transdermal contraceptive patch has a mechanism of action similar to that of the combined oral contraceptives, but it delivers estrogen and progesterone transdermally through the abdominal wall, thus avoiding first-pass metabolism in the liver and enzymatic degradation in the gut. It delivers 35 µg of ethinyl estradiol and 150 µg of norelgestromin (an active metabolite of norgestimate) daily.38 It may cause higher circulating levels of estrogen than a combined oral contraceptive and may be associated with a higher risk of venous thromboembolism, but the evidence is conflicting.39–42
The vaginal ring, made of Silastic, delivers ethinyl estradiol in a low dose (15 µg/day) and etonorgestrel 0.12 mg/day. Like the patch, it has the advantage of bypassing first-pass metabolism in the liver, making it a good option for transplant patients who are taking antirejection drugs, thus avoiding drug interactions.41
Both the transdermal patch and vaginal ring were studied in transplant patients and had favorable results.24,43 The combined hormonal oral contraceptive pills, patch, and ring are in category 4 (unacceptable health risk) in the US MEC in patients with complicated cases, but they are in category 2 in uncomplicated cases.21
Combined hormonal contraceptives should not be considered first-line options by themselves for transplant patients because of their high failure rate with typical use.24
Progestin-only pills
Although progestin-only pills have not been studied specifically in transplant patients, they can be considered for women who have contraindications to estrogen use. Estrogen use is contraindicated in women with a history of venous thromboembolism, thrombogenic mutations, estrogen-dependent neoplasia, hepatocellular adenoma, severe hypertension, vascular disease, and Budd-Chiari syndrome.
Progestin-only pills inhibit ovulation in only about half of a woman’s cycles, but they prevent conception by other mechanisms as well, such as causing thickening of the cervical mucus. They also alter the endometrium to make it unfavorable for implantation and reduce the ciliary activity of the fallopian tube.
Strict adherence is important for effectiveness because progestin-only pills have a shorter half-life than combined hormonal contraceptives and also suppress ovulation less effectively.22 Failure rates are similar or somewhat higher than with combined hormonal contraceptives; with typical use, about 9 in 100 women can become pregnant in the first year.23 According to the US MEC,21 progestin-only pills are classified as category 2 for patients after both complicated and uncomplicated transplants.
MODERATELY EFFECTIVE METHODS (PREGNANCY RATE 10%–25%)
This tier of contraceptives includes all barrier methods, ie, male and female condoms, vaginal diaphragms, cervical caps, and sponges (Table 5).
Condoms (male and female)
When male condoms are used as the only birth control method, pregnancy occurs less often (18% with typical use and 2% with correct use) than with female condoms (21% with typical use and 5% with correct use).23 Male and female condoms are the only contraceptive methods that also prevent transmission of sexually transmitted disease.24
Caps, sponges, diaphragms
Cervical caps, vaginal sponges, and vaginal diaphragms are other forms of barrier contraceptives. All barrier methods should be combined with another contraceptive method to provide reliable protection against pregnancy. These methods are considered category 1 according to the US MEC.
LESS-EFFECTIVE METHODS
Fertility awareness-based methods such as the rhythm method have an associated pregnancy rate of about 25% with typical use and 3% to 5% with correct use23 and cannot be relied on for use by transplant recipients.24
Withdrawal and spermicides are considered least effective and unreliable for pregnancy prevention.
KNOW YOUR OPTIONS
With the growing number of women in their reproductive years receiving solid-organ transplants in the United States, it is increasingly important for healthcare providers to be aware of contraceptive options and reproductive life planning for this high-risk population.
Safe and effective forms of contraception are available, and additional information to guide the choice can be found in the Summary Chart of US MEC for Contraceptive Use, which is also available in a free smart phone app through the CDC.44
Pregnancy after transplant carries high risks, requiring these patients to have special counseling and monitoring. Fortunately, planned pregnancy at least 1 year after transplant can lead to successful outcomes in these women.
