Outcome of clinical pregnancies after ovulation induction using metformin

Different pregnancy outcomes according to the polycystic ovary syndrome diagnostic criteria: a systematic review and meta-analysis of 79 studies

OBJECTIVE

To correlate the distinct diagnostic criteria of polycystic ovary syndrome (PCOS) with the development of maternal and neonatal complications.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Pregnant women with PCOS.

INTERVENTION(S)

Maternal and neonatal complications were compared among women with PCOS diagnosed with different criteria.

MAIN OUTCOME MEASURE(S)

The primary outcomes of gestational diabetes mellitus and preeclampsia (PE) were assessed for every diagnostic criterion.

RESULT(S)

Seventy-nine studies were included. Regarding gestational diabetes, the overall pooled prevalence was 14% (95% confidence interval [CI], 11%-18%; I², 97%), reaching the highest level when polycystic ovarian morphology on ultrasound and 1 of the remaining 2 Rotterdam criteria (1/2 Rotterdam criteria) were used (18%; 95% CI, 13%-24%; I², 20%) and the lowest when polycystic morphology on ultrasound and hyperandrogenism were used (3%; 95% CI, 0%-19%; I², not applicable). Regarding PE, the overall pooled prevalence was 5% (95% CI, 4%-7%; I², 82%). The highest PE prevalence was reported when the National Institutes of Health criteria were used (14%; 95% CI, 5%-33%; I², 90%) and the lowest when menstrual irregularities and 1 of the 2 Rotterdam criteria were used (2%; 95% CI, 1%-3%; I², not applicable).

CONCLUSION(S)

The prevalence of gestational diabetes mellitus in pregnant women with PCOS does not differ according to the criteria used; however, women diagnosed with PCOS per the National Institutes of Health criteria are at higher risk of PE.

Oral Antidiabetic Agents in Pregnancy and Lactation: A Paradigm Shift?

Objective:

To provide information on the use of oral antidiabetic agents in pregnancy and breast-feeding.

Data Sources:

Primary articles were identified by a MEDLINE search (1966–March 2007) using the MeSH headings: pregnancy in diabetics, pregnancy, polycystic ovary syndrome, hypoglycemic agents, glipizide, glyburide, metformin, rosiglitazone, pioglitazone, clinical trial, controlled clinical trial, multicenter study, randomized controlled trial, case–control studies, and cohort studies.

Study Selection and Data Extraction:

All studies using oral antidiabetic agents in pregnancy were evaluated and relevant data were included in the discussion.

Data Synthesis:

Studies of glyburide and glipizide have found little or no transfer of these drugs across the placenta, whereas metformin and rosiglitazone cross readily. Animal studies have found no evidence to suggest that glyburide, glipizide, metformin, or rosiglitazone are teratogenic. In gestational diabetes, glyburide was safe and efficacious; however, 16–19% of women failed to achieve optimal glucose control. No developmental toxicity in infants was observed when metformin was used before and throughout pregnancy in women with polycystic ovarian syndrome (PCOS). Some of the studies involving patients with type 2 diabetes had methodological problems. A randomized controlled trial using metformin for gestational diabetes in the third trimester is underway. The human information is inadequate to evaluate the risk of glipizide or the thiazolidinediones in pregnancy. In breast milk, 3 studies measured nonsignificant amounts of metformin and one study was unable to detect either glyburide or glipizide.

Conclusions:

Neither glyburide nor metformin has caused developmental toxicity in humans. Glyburide has been used for the treatment of gestational diabetes, and metformin has been used in women with PCOS who eventually became pregnant. Additional trials are needed to better define the benefits and risks of oral antidiabetic agents in pregnancy. Metformin, glyburide, and glipizide appear to be compatible with breast-feeding.

First-trimester exposure to metformin and risk of birth defects: a systematic review and meta-analysis

BACKGROUND

Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects.

METHODS

Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate.

RESULTS

Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of their pregnancy. Regarding type 2 diabetic women, we did not identify a sufficient number of studies with metformin exposure during the first trimester to proceed with the meta-analysis.

CONCLUSIONS

There is currently no evidence that metformin is associated with an increased risk of major birth defects in women affected by PCOS and treated during the first trimester. However larger ad hoc studies are warranted in order to definitely confirm the safety and efficacy of this drug in pregnancy.

Type 2 diabetes in pregnancy - An increasing problem

The worldwide epidemic in type 2 diabetes has been associated with an increased diagnosis in young adults. This has lead to a rapid rise in the number of pregnancies complicated by type 2 diabetes. Studies have shown risk of serious adverse outcome, including congenital malformation and perinatal mortality, is the same, or increased, in type 2 diabetes compared to type 1 diabetes. Despite improved glycaemic control in type 2 diabetes compared to type 1 diabetes, rates of perinatal morbidity, including preterm birth and macrosomia, appear to be similar. Risk factors associated with poor pregnancy outcome in women with type 2 diabetes include obesity, ethnicity and poor pregnancy preparation. This review will cover practical aspects of management of type 2 diabetes before, during and after pregnancy, including prepregnancy care, safety of oral hypoglycaemic agents, glycaemic management during labour, and choice of effective contraception.

Continuation of metformin in the first trimester of women with polycystic ovarian syndrome is not associated with increased perinatal morbidity

This study aimed to assess the perinatal outcome, especially foetal growth, following the continuation of metformin during the first trimester of pregnancy. All women with polycystic ovary syndrome (PCOS) treated with metformin in the first trimester and who delivered a baby weighing 500 g or more between 2003 and 2005 were studied. Subjects were matched for age and parity with randomly selected controls. The perinatal outcomes studied were: growth parameters, gestational age, congenital defects, hypoglycaemia and neonatal unit admission. Sixty-six pregnancies were compared with 66 controls; all had singleton deliveries. There was no difference in mean birth weight between the metformin and the control groups (p=0.84). The percentage of small (<10th centile) and large (>90th centile) for gestational age babies was lower in the metformin group. In the metformin group, there were no major congenital malformations and 24% of the babies were admitted to the neonatal intensive care unit (NICU) compared with 27% of the babies in the control group (non-significant). Neonatal hypoglycaemia was less common in the metformin group (18.5% vs. 24.5%) and fewer babies required intravenous glucose therapy (6.3% vs. 12%). We found no evidence that the continuation of metformin in the first trimester of pregnancy was associated with an adverse foetal outcome.

The impact of obesity on female reproductive function

Obesity may be described as the new worldwide epidemic, and its serious impact on morbidity and mortality are well known. As more and more women become obese, the reproductive problems associated with obesity present an ever-growing challenge to physicians involved in their fertility care. The spectrum of reproductive problems associated with obesity encompasses a wide range of disorders including infertility problems, miscarriage and pregnancy complications. In this review, we aim to discuss the impact of obesity on the various aspects of female reproductive function with focus on the clinical aspects of fertility problems in obese women. We finally comment on the available therapeutic options available to this group of women.

The role of metformin in polycystic ovary syndrome: a systematic review

This meta-analysis evaluated the effectiveness of metformin in subfertile women with polycystic ovary syndrome (PCOS). Only randomized trials investigating the effectiveness of metformin and PCOS definition consistent with the Rotterdam consensus criteria, were eligible. Primary outcome was live birth rate. A literature search identified 27 trials. In therapy naïve women, we found no evidence of a difference in live birth rate when comparing metformin with clomifene citrate (CC) [relative risks (RR) 0.73; 95% confidence interval (CI) 0.51-1.1] or comparing metformin plus CC with CC (RR 1.0; 95% CI 0.82-1.3). In CC-resistant women, metformin plus CC led to higher live birth rates than CC alone (RR 6.4; 95% CI 1.2-35); metformin also led to higher live birth rates than laparoscopic ovarian drilling (LOD) (RR 1.6; 95% CI 1.1-2.5). We found no evidence for a positive effect of metformin on live birth when added to LOD (RR 1.3; 95% CI 0.39-4.0) or FSH (RR 1.6; 95% CI 0.95-2.9), or when co-administered in IVF (RR 1.5; 95% CI 0.92-2.5). In IVF, metformin led to fewer cases of ovarian hyperstimulation syndrome (OHSS) (RR 0.33; 95% CI 0.13-0.80). This meta-analysis demonstrates that CC is still first choice therapy for women with therapy naïve PCOS. In CC-resistant women, the combination of CC plus metformin is the preferred treatment option before starting with LOD or FSH. At present, there is no evidence of an improvement in live birth when adding metformin to LOD or FSH. In IVF, metformin leads to a reduced risk of OHSS.

Metformin reduces abortion in pregnant women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are considered to be at increased risk of miscarriage. Since metformin has beneficial effects on the risk factors contributing to first-trimester abortion in PCOS patients, we hypothesized that metformin - owing to its metabolic, endocrine, vascular and anti-inflammatory effects - may reduce the incidence of first-trimester abortion in PCOS women.

MATERIALS AND METHODS

A prospective cohort study was set up to determine the beneficial effects of metformin on PCOS patients during pregnancy. Two hundred non-diabetic PCOS patients were evaluated while undergoing assisted reproduction. One hundred and twenty patients became pregnant while taking metformin, and continued taking metformin at a dose of 1000-2000 mg daily throughout pregnancy. Eighty women who discontinued metformin use at the time of conception or during pregnancy comprised the control group.

RESULTS

Both groups were similar with respect to all background characteristics (age, body mass index, waist/hip ratio, follicle-stimulating hormone, luteinizing hormone, estradiol and dehydroepiandrosterone sulfate levels). Rates of early pregnancy loss in the metformin group were 11.6% compared with 36.3% in the control group (p < 0.0001; odds ratio = 0.23, 95% confidence interval 0.11-0.42).

CONCLUSIONS

Administration of metformin throughout pregnancy to women with PCOS was associated with a marked and significant reduction in the rate of early pregnancy loss.