Clomiphene citrate and pregnancy outcome

Potential Teratogenic Effects of Clomiphene Citrate

Clomiphene citrate (CC) is the oldest drug used to regulate the process of ovulation. Considering the great use of CC over the last 40 years, it is important to understand the possible risks associated with its use. The aim of this review was to evaluate the possible teratogenic effects of CC, analyzing results obtained from animal and human studies. The pharmacokinetics of CC and possible mechanisms involved in teratogenesis are examined. Fetal exposure to CC is possible due to the long half-life of CC and its metabolites. Alarming data have emerged from animal studies, although controversial results come from human studies. There is some evidence regarding a possible association of CC exposure and fetal malformations, mainly neural tube defects and hypospadias, which would require further investigation in order to allow safer use of this useful drug.

Pregnancy after the age of 40

Many regard childbearing as the most life-changing and perhaps the most desirable aspect of a women's life. Correspondingly, reduced fertility has a significant negative impact on a woman and her family. To this end, gynecologists work to preserve and restore fertility. Recently, however, in developed countries, more women are becoming pregnant later in life, whether by choice or circumstance. This could be a direct result of the increasing availability of both effective contraception and infertility treatment, but perhaps more pertinently the changing lifestyles and career choices that modern women make. This article offers a perspective on pregnancy after the age of 40, the impact on maternal and fetal outcomes, the social implications and the importance of prenatal counseling.

Pregnancy Outcome Among Twins Conceived After Subfertility Treatment Compared With Natural Twins: A Population-Based Study

Pregnancy outcome and characteristics of women who conceive following subfertility treatment remains a subject of great interest. We analyzed these variables among 199 women who delivered a registerable twin birth compared with 1773 women who delivered a naturally conceived twin birth in a population-based obstetric cohort drawn from around Oxford, England. Treatment was restricted to conceptions involving simple ovulation induction only. Treated mothers were of significantly higher social class and older, more likely to deliver girls and to be delivered by cesarean section, and significantly less likely to be smokers at the time of antenatal booking and to have delivered previous pregnancies. Pregnancy outcome was similar between the two groups for most measures, with the exception of birthweight which was lower in treated twins, though not significantly so. Overall the results are reassuring with respect to outcome in twin pregnancies following simple ovulation induction.

Recurrent partial hydatidiform mole, with a first twin pregnancy, after treatment with clomiphene citrate

We present a patient, treated for 3 months with clomiphen citrate after 5 years of infertility. This treatment resulted in a twin pregnancy, one degenerated into a partial hydatidiform mole and the other into a very early embryo death. The karyotype was a mosaic one: 63% of metaphases showed triploidy - 69 XXX and 37% diploidy - 46 XX. Despite all medical advice, she returned 8 months later with a new pregnancy, which proved to be a new partial hydatidiform mole, this time a single one. Karyotype was, also, a triploidy - 69 XXX. The genetic map of both genitors was performed, showing no aberrations. Unfortunately, the patient came back, once again, 5 months later, with a new positive pregnancy test. Ultrasonography revealed a new very early embryo death, the histopathological analysis establishing to be a single 'pure' stop in evolution of the pregnancy. As all the three pregnancies obtained after treatment with clomiphene were abnormal, two being partial hydatidiform moles and one being a premature miscarriage, without any genetic aberrations of the genitors, it seems very possible that clomiphene, apart from improving fertility, also increases the risk of abnormal ovum appearance.

Health of children born after ovulation induction

OBJECTIVE

To study the health of children born after ovulation induction (OI).

DESIGN

Nationwide register-based study.

SETTING

The OI children were followed up to the age of 4 years and compared with other children.

PATIENT(S)

The OI children (N = 4,467). Two control groups: all other children (excluding children born after IVF, N = 190,398) and a random sample of those children (n = 26,877).

INTERVENTION(S)

Ovulation induction treatment in ordinary practice.

MAIN OUTCOME MEASURE(S)

Mortality rates and adjusted odds ratios for perinatal outcomes, hospitalizations, health-related benefits, and long-term medication use.

RESULT(S)

A total of 12% of OI and 2% of control children were multiples. Even after stratifying for multiplicity and adjusting for the available confounding factors (region, smoking, maternal age, socioeconomic position, and parity for perinatal health and mother's socioeconomic position for other indicators), most indicators showed worse health among OI children compared with control children. The OI children had poorer perinatal health and more episodes of long hospitalization than the control children. Singleton OI children had more long-term illnesses in childhood, as measured by child disability allowance, long-term medication use, and hospital care episodes.

CONCLUSION(S)

Either OI treatment or the reasons for the treatment increase the risk of health problems in early childhood.

ART: iatrogenic multiple pregnancy?

Assisted reproductive technologies (ART) are now widely accepted as effective treatment for most causes of infertility. With improving success rates, attention has turned to the problem of multiple pregnancies, which are associated with a poor perinatal outcome, maternal complications and significant financial consequences. The challenge is to reduce multigestational pregnancies while maintaining good treatment outcomes. Methods to prevent multiple pregnancy include restrictive use of ART in couples with a good chance of spontaneous pregnancy, cautious use of gonadotrophins, and increased use of natural-cycle intra-uterine insemination and elective single embryo transfer in in-vitro fertilization and intracytoplasmic sperm injection. The aim of this article is to review the contribution of fertility treatment to multiple pregnancies and strategies for reducing multiples in ART.

Complications of IVF and ovulation induction

BACKGROUND

The frequency and importance of complications of IVF and other ovulation induction (OI) are poorly known. We examined the occurrence of serious complications and miscarriages leading to hospitalization or operation after IVF (including microinjections and frozen embryo transfers) and OI treatment (with or without insemination).

METHODS

Women who received IVF (n = 9175) or OI treatment (n = 10 254) 1996-1998 in Finland were followed by a register linkage study until 2000.

RESULTS

After the first IVF treatment cycle, 14 per 1000 women had a serious case of OHSS (ovarian hyperstimulation syndrome), with 23 per 1000 throughout the study period (mean of 3.3 treatments). The corresponding values after OI were very low. The rates of registered ectopic pregnancies and miscarriages after IVF were nine and 42 respectively per 1000 women, with corresponding rates after OI of eight and 42. Infections and bleeding were not common after IVF and even rarer after OI. Overall, 15% of IVF and 8% of OI women had at least one hospital episode during the study period.

CONCLUSIONS

Though there was a low risk of complications after each IVF treatment cycle, repeated attempts resulted in serious complications for many women, and these occurred much more often than after ovulation induction alone.

Oral anti-oestrogens and medical adjuncts for subfertility associated with anovulation

BACKGROUND

Infertility due to anovulation is a common problem in women. The first line oral treatment is with anti-oestrogens, such as clomiphene citrate. Unfortunately there may be resistance and alternative and adjunctive treatments have been developed. These include tamoxifen, dexamethasone, bromocriptine and aromatase inhibitors (AIs).

OBJECTIVES

To determine the relative effectiveness of anti-oestrogen agents, with or without medical adjuncts, in women with WHO group 2 anovulation.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trial register (searched 5th July 2004), CENTRAL (The Cochrane Library Issue 2 2004), MEDLINE (1966 to June 2004) and EMBASE (1980 to June 2004) for identification of relevant randomised controlled trials (RCTs). Additionally the United Kingdom National Institute for Clinical Excellence (NICE) guidelines and the references of relevant reviews and RCTs were searched.

SELECTION CRITERIA

RCTs that compare oral anti-oestrogen agents for ovulation induction (alone or in conjunction with medical adjuncts) in anovulatory subfertility, were considered for inclusion in the review. Metformin and other insulin sensitizing agents were not included. Hyperprolactinaemic infertility was not included.

DATA COLLECTION AND ANALYSIS

Data extraction and quality assessment was done independently by two reviewers. The primary outcome was live birth, secondary outcomes were: pregnancy, ovulation, miscarriage, multiple pregnancy, overstimulation, ovarian hyperstimulation syndrome and patient reported adverse effects.

MAIN RESULTS

Twelve RCTs were found and included in this review. No trials reported live birth as an outcome. Miscarriage and multiple pregnancy rates were poorly reported. Clomiphene was shown to be effective in increasing pregnancy rate when compared to placebo (fixed OR 5.8, 95% CI 1.6 to 21.5; NNT 5.9, 95% CI 3.6 to 16.7). No evidence of a difference in effect was found between clomiphene and tamoxifen (fixed OR 1.0, 95% CI 0.5 to 2.1). The use of clomiphene in combination with tamoxifen did not find any evidence of effect on pregnancy rate when compared to clomiphene alone (fixed OR 3.3, 95% CI 0.1 to 91.6). The comparison between two AIs (letrozole and anastrozole) did not find any evidence of a difference in effect on pregnancy rate (fixed OR 1.9, 95% CI 0.4 to 8.9). For the intervention of clomiphene plus ketoconazole vs clomiphene no evidence of a difference in effect for pregnancy rate was found (fixed OR 2.4, 95% CI 0.9 to 6.4). For clomiphene plus bromocriptine vs clomiphene no evidence of a difference in effect on pregnancy rate was found (fixed OR 1.0, 95% CI 0.3 to 3.0) rates. However, clomiphene plus dexamethasone treatment resulted in a significant improvement in the pregnancy rate (fixed OR 11.3, 95% CI 5.3 to 24.0; NNT 2.7, 95% CI 2.1 to 3.6) when compared to clomiphene alone as did clomiphene plus pretreatment with combined oral contraceptives (fixed OR 27.2, 95% CI 3.1 to 235.0; NNT 2.0, 95% CI 1.4 to 3.4).

AUTHORS' CONCLUSIONS

This review shows evidence supporting the effectiveness of the current first line treatment, clomiphene citrate. No evidence of a difference in effect was found between clomiphene and tamoxifen. The use of dexamethasone as an adjunct to clomiphene therapy appears promising as do combined oral contraceptives. This review has highlighted a gap in the literature on effects of these drugs on outcomes such as miscarriage rate. Evidence in favour of these interventions is flawed. RCTs of adequate power and of high methodological quality are required for the older treatments such as clomiphene, alone and with medical adjuncts, and also for the newer drugs such as the AIs.

Pregnancy outcomes with increased clomiphene citrate dose

Our objective was to evaluate whether ovulation induction with an increased clomiphene citrate dose of 150-250 mg/day for 5 days adversely affected pregnancy outcome. A retrospective chart review of 1910 medical records yielded 119 pregnancies with sufficient information regarding domiphene dose and pregnancy outcome. Of the 84 pregnancies that followed clomiphene doses of 50-100 mg/day, 32.1% ended in spontaneous abortion, 10.7% in ectopic gestation, 1.2% with congenital malformations, 2.4% in stillbirth and 53.6% in normal gestation. Of the 35 pregnancies that followed clomiphene doses of 150-250 mg/day, 34.3% ended in spontaneous abortion, 5.7% in ectopic gestation, 2.9% with congenital malformations, 2.9% in stillbirth and 54.3% in normal gestation. These differences were not statistically significant. These data suggest that a clomiphene dose of 150-250 mg/day does not appear to increase adverse pregnancy outcomes.

Ovulation induction--optimizing results and minimizing risks

The aim of ovulation induction therapy should be, wherever possible, to correct the underlying disturbance and achieve safe, repeated unifollicular ovulation to achieve the live birth of singleton babies. This article outlines the main causes of anovulatory infertility but deals mostly with the management of anovulatory polycystic ovary syndrome (PCOS), which is the most common problem to confront specialists in reproductive medicine. PCOS is associated with insulin resistance, particularly in those who are overweight. Thus, strategies to achieve weight loss and improve insulin sensitivity, including the use of drugs such as metformin, enhance reproductive function. Therapies to induce ovulation involve first the use of the anti-oestrogen clomiphene citrate. For those who fail to ovulate in response to clomiphene citrate, the principal options include parenteral gonadotrophin therapy or laparoscopic ovarian diathermy.

Ovulation induction for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the commonest cause of anovulatory infertility. Various factors influence ovarian function, and fertility is adversely affected by an individual being overweight or having high serum concentrations of LH. Strategies to induce ovulation include weight loss, oral anti-oestrogens (principally clomiphene citrate), parenteral gonadotrophin therapy and laparoscopic ovarian surgery. There have been no adequately powered randomized studies to determine which of these therapies provides the best overall chance of an ongoing pregnancy. Women with PCOS are at risk of ovarian hyperstimulation syndrome (OHSS) and so ovulation induction has to be monitored carefully with serial ultrasound scans. The recognition of an association between hyperinsulinaemia and PCOS has resulted in the use of insulin sensitizing agents, such as metformin, which appear to ameliorate the biochemical profile and improve reproductive function.

Funding in vitro fertilization treatment for persistent subfertility: the pain and the politics

OBJECTIVE

To consider the arguments for and against funding for in vitro fertilization (IVF) and to explore potential avenues for policy change.

DESIGN

Narrative literature review, policy analysis.

SETTING

University Department of Obstetrics and Gynecology.

PATIENT(S)

Sub-fertile women and men.

INTERVENTION(S)

Fertility treatments, in particular IVF.

RESULT(S)

The two main arguments used against funding for IVF are that [1] subfertility is a social, not a medical problem, and therefore its treatment is not medically indicated or necessary, and [2] the clinical effectiveness of IVF is unproven. These and other major arguments are critiqued.

CONCLUSION(S)

Dismissing IVF as medically unnecessary seems premature because medical necessity has not been operationally defined. Demonstrating IVF effectiveness through a randomized trial has not been done but is feasible: a multicenter trial is currently underway in Canada. Dealing with the concern that subfertility treatment challenges the role of women in society, as well as with questions of cost-effectiveness, are more difficult challenges that deserve further debate. The potential for unethical uses and broader social implications of IVF add to its dubious status and provide a convenient rationale for refusing to pay. However, none of these concerns is unique to IVF: many currently covered health services are susceptible to the same criticisms. For all services, judgments of eligibility for coverage should be consistent and transparent and should explicitly separate the issues of cost from other factors.

Risk of stillbirth from medications, illnesses and medical procedures

Associations between stillbirth and 14 medical exposures during pregnancy were examined using deliveries in 1984 in 10 California counties. Cases (n = 332) were stillbirths and infant deaths within 24 h of birth. Randomly selected live births served as controls (n = 357) and were frequency matched by maternal age and county. Using questionnaire and vital statistics data, logistic regression and proportional hazards modelling were performed with adjustment for potential confounders. The most prevalent exposures were ultrasound (65% of cases, 58% of controls) and acetaminophen (45% of cases, 54% of controls). Prescription pain medication, when taken in the first 2 gestational months, was strongly associated with stillbirths due to congenital anomalies (odds ratio = 7.5, 95% confidence interval [CI] 2.3, 24.1). First and second trimester use of prescription pain or migraine medication was positively associated with all stillbirths (rate ratio [RR] range 1.3-1.6). Fertility drugs were positively associated with stillbirths in total and stillbirths due to complications of the placenta, cord and membranes (RR = 1.8, 95% CI 0.8, 4.1; and RR = 2.5, 95% CI 0.9, 7.2 respectively). No associations were found for aspirin, amniocentesis, diagnostic X-rays or fever, consistent with previous studies. This report is among the few studies of specific causes of stillbirth and medical exposures by gestational time window.

Endocrine methods of ovulation induction

The rationale of ovulation induction is to achieve the development of a single follicle and ultimately a singleton healthy baby. Problems faced by women with anovulatory polycystic ovary syndrome are the sensitivity of the ovary to stimulation and health issues such as obesity. This chapter will discuss medical management including strategies to lose weight, address hyperinsulinaemia with insulin-sensitizing agents, such as metformin, and outline methods of ovulation induction from the usual first-line therapy of clomiphene citrate and the subsequent use of gonadotrophin therapy in clomiphene-resistant patients. Appropriately directed surgical ovulation induction with laparoscopic ovarian diathermy appears to be as efficacious as gonadotrophin therapy but will not be discussed in the context of this chapter.

Clinical uses of antiestrogens

An antiestrogen is a compound that blocks the action of estrogen. Most synthetic antiestrogens have agonistic or antagonistic activity depending on the tissue and the endogenous estrogen mileu. The triphenylethylene derivatives, clomiphene and tamoxifen, are the antiestrogens in greatest clinical use. Their biologic effects, clinical indications, and risks are reviewed. Novel antiestrogens which are beginning to be studied clinically include the benzothiophene derivative, raloxifene and the "pure" antiestrogens such as ICI 182,780. New clinical indications for existing compounds as well as the development of novel antiestrogens may lead to better treatment options for endocrine-dependent conditions.

Singleton and twin confinements associated with infertility treatments

A cross-sectional sample of 150 singleton and 159 twin confinements delivered in Western Australia in 1991 were randomly sampled in 1993; 63% of the women responded to a postal questionnaire. Thirteen percent of respondents with singletons and 26% of those with twins reported having problems conceiving at some stage in their life. Six percent of those who had singleton confinements and 22% of those women who had twin confinements sought fertility advice prior to the conception of the index pregnancy. One percent (95% CI 0.03%, 5.5%) of women with singletons received infertility treatment compared with 17% (95% CI 10.4%, 26.3%) of those with twins. Overall 82.7% (95% CI 75.2%, 90.1%) of twin confinements followed spontaneous conception, 11.2% (95% CI 5.7%, 19.2%) followed ovarian stimulation treatment alone and 6.1% (95% CI 2.3%, 12.9%) followed IVF or GIFT procedures. The probability of a spontaneous twin confinement was 1 in 95. It was concluded that nearly twice as many twin pregnancies were associated with ovarian stimulation treatment given alone than with IVF and GIFT combined. The routinely collected data about assisted twin conceptions provide an incomplete picture with regard to the role of different infertility treatment modalities.