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Year : 2021  |  Volume : 25  |  Issue : 2  |  Page : 84-86

Pregnancy and neonatal outcome with maternal exposure to finasteride: Case series

Department of Dermatology, King Saud University, King Saud University Medical City, Riyadh, Saudi Arabia

Date of Submission15-Mar-2021
Date of Acceptance09-Jun-2021
Date of Web Publication29-Mar-2022

Correspondence Address:
Dr. Hessah F BinJadeed
Department of Dermatology, King Saud University, King Saud University Medical City, Riyadh
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jdds.jdds_33_21

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Background: Finasteride, a type II 5-α reductase inhibitor, is approved for the management of benign prostate hyperplasia and male pattern hair loss. Finasteride is used off-label for female pattern hair loss. In utero fetal exposure to finasteride might lead to external genital anomalies in males. Purpose: The aim of this study is to assess the outcomes of in utero finasteride exposure. Methods: We report seven pregnant women with maternal exposure to finasteride. A detailed history was obtained from patients after delivery. Results: In one woman who was pregnant with twin boys, one boy died at the 16th week of gestation and the other delivered at the 34th week of gestation with hypospadias. Another woman had threatened abortion and delivered a normal healthy baby girl. A third had induced elective abortion in the 9th week of gestation. The outcomes of the other four pregnancies were completely healthy, three girls and one boy. Conclusion: External genital anomalies may occur in male fetuses exposed in utero to finasteride depending on the timing of exposure.

Keywords: Androgenetic alopecia, female pattern hair loss, finasteride, maternal exposure, pregnancy, type II 5-a reductase inhibitor

How to cite this article:
BinJadeed HF, Alajlan A. Pregnancy and neonatal outcome with maternal exposure to finasteride: Case series. J Dermatol Dermatol Surg 2021;25:84-6

How to cite this URL:
BinJadeed HF, Alajlan A. Pregnancy and neonatal outcome with maternal exposure to finasteride: Case series. J Dermatol Dermatol Surg [serial online] 2021 [cited 2022 Jul 2];25:84-6. Available from: https://www.jddsjournal.org/text.asp?2021/25/2/84/341205

  Introduction Top

Androgenetic alopecia (AGA) is the most common cause of hair loss with a pattern distribution in predisposed males and females. Hair experts typically refer to AGA as male and female pattern hair loss.[1] Dihydrotestosterone (DHT) plays an important role in the pathogenesis of androgenic alopecia. Finasteride is a type II 5-α reductase inhibitor that inhibits the conversion of testosterone to DHT. Finasteride has been approved for the management of men with AGA.[2]

The only approved treatment for women with AGA is minoxidil.[3],[4] Finasteride is used by many dermatologists off-label for women and can be effective.[3],[5],[6],[7] Finasteride is teratogenic in male fetuses.[3] A recently published case report of maternal use of finasteride suggested that until the 5th week of gestation, finasteride does not result in any dysmorphic features in the male fetus.[8] The purpose of our study was to assess the outcomes in seven women with in utero finasteride exposure.

  Methods Top

The present study includes seven pregnant women were following dermatology clinic for female pattern hair loss and who were exposed to finasteride during pregnancy. All patients discontinued finasteride immediately upon discovering their pregnancy. All of our patients had signed consent forms before starting finasteride treatment, which warned the patients to refrain from becoming pregnant during treatment and for 1 month after the treatment had ended. All seven pregnancies were unplanned. A detailed medical, gynecological, and obstetric history was obtained from the patients after delivery [Table 1].
Table 1: A detailed medical, gynecological, and obstetric history seven pregnant women exposed to finasteride during pregnancy

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  Results Top

The age of the patients ranged between 27 and 38 years old. All patients were taking finasteride for hair loss; three of the patients were taking 2.5 mg daily, while the other four patients were taking 5 mg daily. Most of the patients reported a good response to the treatment, except one who reported no response; however, she received the medication for only 2 months (case 1). All patients were healthy and reported no medical illness. One patient was also taking isotretinoin to treat acne, and therefore, decided to abort the pregnancy (case 7).

Two of the seven patients reported complications during pregnancy. One reported threatened abortion; she was 27-year-old, having one living child, and had been receiving 5 mg daily from 9 months before pregnancy until the 2nd week of pregnancy. However, she vaginally delivered a full-termed normal baby girl (case 5). The other patient who reported complication was a 32-year-old woman who had one previous abortion and two living children, became pregnant with male twins, and had been exposed to 2.5 mg finasteride daily until the 11th week of pregnancy. One of the twins died at the 16th week of gestation, and the other child was delivered at the 34th week of gestation with hypospadias; otherwise, he appeared completely healthy (case 6). Among the other four patients, one pregnant woman who was exposed to 5 mg finasteride daily until the end of the 2nd month of pregnancy gave birth to a full-term normal healthy boy (case 4). The outcomes of the last three pregnancies were three healthy baby girls (case 1, 2, and 3).

  Discussion Top

DHT plays a major role in the development of the external genitalia of a male fetus; it is responsible for the masculinization of the urogenital sinus, the genital tubercle, and folds.[9] DHT is converted from testosterone by the 5-α reductase enzyme, which is inhibited by finasteride.[2] Thus, inhibiting the 5-α reductase enzyme in pregnancy would be expected to affect the development of male external genitalia.[9] This is supported by series studies done in pregnant rats with male fetuses exposed to finasteride. Finasteride exposure leads to decreased distance between the anterior edge of the anus and the posterior base of the genital tubercle. Furthermore, these rats had hypospadias, decreases in penile length,[10] and nipple retention.[11]

There have been a few reported cases of hypospadias in male children whose mother had been exposed to finasteride until the 18th week of gestation.[12] However, another case was reported for a pregnant lady exposed to finasteride during the first 5 weeks of pregnancy, and she delivered a normal baby boy with no dysmorphic features.[8] This could be explained by the timing of fetal external genital development and the timing of maternal finasteride exposure. In the rat studies, the external genital anomalies were more prominent when the period of exposure to finasteride was extended to the mid-gestation.[10] Moreover, in the rhesus monkey study, exposing pregnant mothers to finasteride during the critical period of external genitalia development resulted in external genital anomalies in male fetuses. Nevertheless, when finasteride was given to pregnant rabbits with male fetuses and stopped before the period of genital development, no genital anomalies were observed.[13] In this study, maternal exposure to finasteride up to the 8th week of gestation appeared to show no harm to the male fetus (case 4). Among our cases, one of the patients pregnant with twins was exposed up until the 11th week of gestation; she lost one child and gave birth to one preterm baby boy with hypospadias (case 6). The loss of one of the twins cannot be confidently attributed to the finasteride; however, we believe the hypospadias was likely related to the finasteride exposure.

No genital anomalies were detected in female fetuses in rats, rabbits, or rhesus monkeys.[10],[13] However, an aphalangia was reported in a baby girl born to a mother exposed to finasteride until the 6th week of gestation, with no other risk factors.[14] In this study, no genital anomalies or any other anomalies were recognized in all female fetuses with various periods of exposure (until the 8th week of gestation) finasteride.

The use of teratogenic medications in women of child-bearing potential could be controversial. Based on our 15 years of experience, most women appear to adequately understand the risks and take appropriate measures to avoid pregnancy, however even rare failures to do so can lead to devastating outcome. Avoiding use in women of child-bearing potential when possible may be prudent. When the drug is needed in women of childbearing, giving written instructions and having patients sign those instructions may, to some extent, help mitigate the risk.

  Conclusion Top

In conclusion, the neonatal outcome of in utero finasteride exposure depends on the gender of the fetus. Female fetuses did not have any genital anomalies or any other anomalies. Only some of the male fetuses had genital anomaly, and this can be explained by the time of exposure.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Kanti V, Messenger A, Dobos G, Reygagne P, Finner A, Blumeyer A, et al. Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men-Short version. J Eur Acad Dermatol Venereol 2018;32:11-22.  Back to cited text no. 1
McClellan KJ, Markham A. Finasteride: A review of its use in male pattern hair loss. Drugs 1999;57:111-26.  Back to cited text no. 2
Kelly Y, Blanco A, Tosti A. Androgenetic alopecia: An update of treatment options. Drugs 2016;76:1349-64.  Back to cited text no. 3
Adil A, Godwin M. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis. J Am Acad Dermatol 2017;77:136-141.e5.  Back to cited text no. 4
Boersma IH, Oranje AP, Grimalt R, Iorizzo M, Piraccini BM, Verdonschot EH. The effectiveness of finasteride and dutasteride used for 3 years in women with androgenetic alopecia. Indian J Dermatol Venereol Leprol 2014;80:521-5.  Back to cited text no. 5
[PUBMED]  [Full text]  
Hu AC, Chapman LW, Mesinkovska NA. The efficacy and use of finasteride in women: A systematic review. Int J Dermatol 2019;58:759-76.  Back to cited text no. 6
Won YY, Lew BL, Sim WY. Clinical efficacy of oral administration of finasteride at a dose of 2.5 mg/day in women with female pattern hair loss. Dermatol Ther 2018;31:e12588.  Back to cited text no. 7
AlSaad D, Lee BH, Al-Obaidly S. Finasteride use during pregnancy and early neonatal outcome: A case report. Int J Clin Pharm 2018;40:803-5.  Back to cited text no. 8
Maes M, Sultan C, Zerhouni N, Rothwell SW, Migeon CJ. Role of testosterone binding to the androgen receptor in male sexual differentiation of patients with 5 alpha-reductase deficiency. J Steroid Biochem 1979;11:1385-92.  Back to cited text no. 9
Clark RL, Antonello JM, Grossman SJ, Wise LD, Anderson C, Bagdon WJ, et al. External genitalia abnormalities in male rats exposed in utero to finasteride, a 5 alpha-reductase inhibitor. Teratology 1990;42:91-100.  Back to cited text no. 10
Bowman CJ, Barlow NJ, Turner KJ, Wallace DG, Foster PM. Effects of in utero exposure to finasteride on androgen-dependent reproductive development in the male rat. Toxicol Sci 2003;74:393-406.  Back to cited text no. 11
Overview of Off-Label Use of 5-Alpha Reductase Inhibitors in Women. Netherland Pharmacovigilance Center Lareb; April 2015. Available from: http://www.lareb.nl/?lang=en-GB. [Last accessed on 2020 Mar13].  Back to cited text no. 12
Center for Drug Evaluation and Research, Application Number, NDA 20-788/S-017. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/nda/2011/020788Orig1s017.pdf. [Last accessed on 2021 Mar 01].  Back to cited text no. 13
Sallout BI, Al Wadi KA. Aphalangia possibly linked to unintended use of finasteride during early pregnancy. Ann Saudi Med 2009;29:155-6.  Back to cited text no. 14
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