Pregnancy and CAH: What every woman with Classical CAH Should Know

Fall 2005 CARES Foundation, Inc.

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Pregnancy and CAH:
What every woman with Classical CAH Should Know
by Ellen Seely, M.D.
Rhonda Bentley-Lewis, M.D., MBA


Women with classical Congenital Adrenal Hyperplasia (CAH) can conceive and have healthy pregnancies and deliveries with the proper prenatal care. However, every woman with CAH should be well-informed in a few key areas prior to embarking on this journey. Can a woman with CAH become pregnant? Yes! However, when CAH is not well controlled with medications, overproduction of male sex hormone may interfere with ovulation and prevent pregnancy from occurring. Adjustment of the steroid dose can often lead to restoration of ovulation. When adjustment of the steroid dose alone is not successful, clomiphene citrate, a pill that can increase the likelihood of ovulation, can be used. The use of clomiphene citrate is not specific for women with CAH and is used in many women who are not ovulating regularly. Once ovulation is occurring, sexual intercourse with a fertile partner is usually the next step in achieving a pregnancy. However, some women with CAH have discomfort during sexual intercourse, as their vagina may be shortened due to the androgen exposure in utero. In this situation, some women may choose surgery to enlarge the vagina or to have sperm injected directly into the vagina by an obstetrician. When should a woman with CAH seek help with family planning? Once a woman with CAH decides she wants to conceive, she should seek out the supervision of a medical endocrinologist and an obstetrician who are experienced in the management of CAH during pregnancy. The endocrinologist will help with regularization of the steroid dose to achieve optimal ovulation and then will work with the obstetrician during pregnancy on medication adjustment. Occasionally, an Ob-Gyn trained in reproductive endocrinology and infertility may need to help if pregnancy does not occur with regularization of menses. Prior to pregnancy, consultation with a geneticist is also recommended to evaluate and inform the couple of the genetic risk of having a child with CAH and options for prenatal treatment as outlined in the CARES Foundation Winter 2004-05 newsletter, volume4, issue 1. What is the chance of a woman with CAH having a child affected with CAH? The genetics of CAH, including how the genetics may translate into the clinical manifestations, have been detailed in the CARES Winter 2004-05 newsletter. Briefly, genetic evaluation will provide information regarding the risk to the fetus of having CAH. Because the carrier rate of CAH can be significant, as high as 1 in 30 in some populations, it is important to genetically evaluate (genotype) the father to determine if he has CAH, is a carrier, or is unaffected. This information will then be used in conjunction with the mother’s genotype information to understand the possible outcomes for the unborn child. For example, when the mother has CAH, if the father is a carrier of CAH, there is a 50 percent chance that the fetus will be affected and 50 percent chance that the fetus will be a carrier. If the father is unaffected, then all children will be carriers. What are particular medical issues that have to be managed during pregnancy in a woman with CAH? During pregnancy in women without CAH, the steroid levels in the body normally increase. Therefore, the dose of steroid a woman with CAH takes may need to be increased during pregnancy and the dose should be monitored carefully by the woman’s medical endocrinologist. Most women with CAH are kept on their same form of steroid. Prednisone and hydrocortisone do not cross the placenta well and are not thought to affect the fetus. Some women need to increase their dose of fludrocortisone (Florinef) while others increase their salt intake alone. Once pregnancy occurs, it is important that the mother continue to take her steroid medication regularly, not only for her well-being but also for that of the fetus. Very high levels of male sex hormone in the mother could potentially cross the placenta and make a female fetus virilized. The mother’s steroid dose should be adjusted so that maternal androgens run in the upper limit of normal range for pregnancy. In addition, the pregnant woman has a “back up” system in place- the placenta has a built in enzyme called placental aromatase that metabolizes the majority of the male sex hormone produced by the mother. Therefore, with adjustment of maternal steroid doses and good placental function, a female fetus, who is not herself affected with CAH, will not have problems with virilization. Are there any particular concerns a woman with CAH should have about labor and delivery? Labor is a stressful time due to exertion and, at times, discomfort. As the medical endocrinologist often advises an increase in the steroid dose at the time of stress from an illness, the doctor will increase the steroid dose during labor and delivery and then return the dose to the baseline dose in the several days after delivery. In addition, it appears the chance of having a cesarean section may be increased in women with CAH. This may be due to limited pelvic size and shape because of exposure to higher male sex levels during early development. In addition, some experts recommend cesarean section for women who have had prior vaginal reconstructive surgery. Can women with CAH have healthy newborns? Yes! Women with CAH can and do have healthy pregnancies and children. There are several reports of normal infants born to women with CAH. Many endocrinologists who care for women with CAH take care of women who have had healthy pregnancies. At the Endocrine and Hypertensive Disorders of Pregnancy Program at Brigham and Women’s Hospital, of the eight pregnancies we have taken care of, all have had healthy infants. In most states, neonates are screened for 21-hydroxylase deficiency automatically as part of the neonatal screen that takes place using blood obtained by a heel stick of the neonate. Screening for 21-hydroxylase deficiency is required to take place in 42 states as of August 12, 2005 (US National Newborn Screening Report). Summary Women with CAH can and do have healthy pregnancies and babies. Important to optimizing the likelihood for a healthy pregnancy is 1) family planning and counseling with endocrinology, obstetrics and genetics prior to pregnancy and 2) close follow-up with both endocrinology and obstetrics during pregnancy and delivery.
Ellen Seely, M.D. is a member of CARES’ Medical Advisory Board. She is the Director of Clinical Research in the Division of Endocrinology, Diabetes and Hypertension at the Brigham and Women’s Hospital in Boston and Associate Professor of Medicine at Harvard Medical School.

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