What proportion of multiple births are due to ovulation induction? A register-based study in Italy

Increased risk of severe maternal morbidity in women with twin pregnancies resulting from oocyte donation

STUDY QUESTION

Is there a difference in the risk of serious maternal complications during pregnancy and the postpartum in twin pregnancies according to mode of conception: natural conception, non-IVF fertility treatment, IVF, ICSI or oocyte donation?

SUMMARY ANSWER

Women with twin pregnancies after medically assisted reproduction (MAR) had an overall risk of serious maternal complications 30% higher compared with women with natural twin pregnancies, and this association varied according to the MAR procedure; the risk was increased by 50% with IVF using autologous oocytes and by 270% with oocyte donation.

WHAT IS KNOWN ALREADY

IVF has been reported as a risk factor for serious maternal complications in several concordant studies of singleton pregnancies. For twin pregnancies, this association is less well documented with imprecise categorisation of the mode of conception, and results are contradictory.

STUDY DESIGN, SIZE, DURATION

This is a secondary analysis of the national, observational, prospective, population-based cohort study of twin pregnancies (JUmeaux Mode d'Accouchement), which took place in France from 10 February 2014 through 1 March 2015. All French maternity units performing more than 1500 annual deliveries were invited to participate, regardless of their academic, public or private status or level of care. Of the 191 eligible units, 176 (92%) participated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women with a twin pregnancy who gave birth at or after 22 weeks of gestation were eligible (N = 8823 women included). We excluded women whose mode of conception was unknown (n = 75). Serious maternal complications were regrouped within the recently emerged concept of severe acute maternal morbidity (SAMM), as a binary composite outcome. The exposure of interest was the mode of conception, studied in five classes: natural conception (reference group), non-IVF fertility treatment including insemination and ovarian stimulation, IVF with autologous oocyte, ICSI with autologous oocyte and oocyte donation. To assess the association between the mode of conception and SAMM, we used multivariate logistic regression to adjust for confounders. Structural equation modelling (SEM) was used to explore the contribution to this association of potential intermediate factors, i.e. factors possibly caused by the mode of conception and responsible for SAMM: non-severe pre-eclampsia, placenta praevia and planned mode of delivery.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 8748 women of the study population, 5890 (67.3%) conceived naturally, 854 (9.8%) had non-IVF fertility treatment, 1307 (14.9%) had IVF with autologous oocytes, 368 (4.2%) had ICSI with autologous oocytes and 329 (3.8%) used oocyte donation. Overall, 538 (6.1%) developed SAMM. Women with twin pregnancy after any type of MAR had a higher risk of SAMM than those with a natural twin pregnancy, after adjustment for confounders (7.9% (227/2858) compared to 5.3% (311/5890), adjusted odds ratio (aOR) 1.3, 95% CI 1.1-1.6). This association varied according to the MAR procedure. The risk of SAMM was higher among women with IVF using either autologous oocytes (8.3%; 108/1307) or oocyte donation (14.0%; 46/329) compared with the reference group (respectively aOR 1.5, 95% CI 1.1-1.9 and aOR 2.7, 95% CI 1.8-4.1) and higher after oocyte donation compared with autologous oocytes (aOR 1.7, 95% CI 1.1-2.6). Conversely, the risk of SAMM for women with non-IVF fertility treatment (6.2%; 53/854) and with ICSI using autologous oocytes (5.4%; 20/368) did not differ from that of the reference group (5.3%; 311/5890) (respectively aOR 1.1, 95% CI 0.8-1.5 and aOR 0.9, 95% CI 0.6-1.5). The tested intermediate factors poorly explained these increased risks.

LIMITATIONS, REASONS FOR CAUTION

Beyond the confounders and intermediate factors considered in our analysis, specific causes of infertility and specific aspects of infertility treatments may explain the differences in the risk of SAMM by mode of conception. However, these data were not available.

WIDER IMPLICATIONS OF THE FINDINGS

Our study showed an increased risk of SAMM in women with twin pregnancies after MAR, notably after IVF using autologous oocytes and particularly after oocyte donation. To avoid unnecessary exposure to the high-risk combination of MAR and multiple pregnancies, transfer of a single embryo should be encouraged whenever possible. Knowledge of these differential risks may inform discussions between clinicians and women about the mode of conception and help to optimise obstetric care for women in subgroups at higher risk.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a grant from the French Ministry of Health (Programme Hospitalier de Recherche Clinique, AOM2012). There are no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Severe acute maternal morbidity in multiple pregnancies: a nationwide cohort study

BACKGROUND

Adverse neonatal outcomes in multiple pregnancies have been documented extensively, in particular those associated with the increased risk of preterm birth. Paradoxically, much less is known about adverse maternal events. The combined risk of severe acute maternal morbidity in multiple pregnancies has not been documented previously in any nationwide prospective study.

OBJECTIVE

The objective of the study was to assess the risk of severe acute maternal morbidity in multiple pregnancies in a high-income European country and identify possible risk indicators.

STUDY DESIGN

In a population-based cohort study including all 98 hospitals with a maternity unit in The Netherlands, pregnant women with severe acute maternal morbidity were included in the period Aug. 1, 2004, until Aug. 1, 2006. We calculated the incidence of severe acute maternal morbidity in multiple pregnancies in The Netherlands using The Netherlands Perinatal Registry. Relative risks (RR) of severe acute maternal morbidity in multiple pregnancies compared with singletons were calculated. To identify possible risk indicators, we also compared age, parity, method of conception, onset of labor, and mode of delivery for multiple pregnancies using The Netherlands Perinatal Registry as reference.

RESULTS

A total of 2552 cases of severe acute maternal morbidity were reported during the 2 year study period. Among 202 multiple pregnancies (8.0%), there were 197 twins (7.8%) and 5 triplets (0.2%). The overall incidence of severe acute maternal morbidity was 7.0 per 1000 deliveries and 6.5 and 28.0 per 1000 for singletons and multiple pregnancies, respectively. The relative risk of severe acute maternal morbidity compared with singleton pregnancies was 4.3 (95% confidence interval [CI], 3.7-5.0) and increased to 6.2 (95% CI 2.5-15.3) in triplet pregnancies. Risk indicators for developing severe acute maternal morbidity in women with multiple pregnancies were age of ≥ 40 years, (RR, 2.5 95% CI, 1.4-4.3), nulliparity (RR, 1.8, 95% CI, 1.4-2.4), use of assisted reproductive techniques (RR, 1.9, 95% CI, 1.4-2.5), and nonspontaneous onset of delivery (RR, 1.6, 95% CI, 1.2-2.1). No significant difference was found between mono- and dichorionic twins (RR, 0.8, 95% CI, 0.6-1.2).

CONCLUSION

Women with multiple pregnancies in The Netherlands have a more than 4 times elevated risk of sustaining severe acute maternal morbidity as compared with singletons.

Chinese herbal medicine for infertility with anovulation: a systematic review

The aim of this systematic review is to assess the effectiveness and safety of Chinese herbal medicine (CHM) in treatment of anovulation and infertility in women. Eight (8) databases were extensively retrieved. The Chinese electronic databases included VIP Information, CMCC, and CNKI. The English electronic databases included AMED, CINAHL, Cochrane Library, Embase, and MEDLINE(®). Randomized controlled trials using CHM as intervention were included in the study selection. The quality of studies was assessed by the Jadad scale and the criteria referred to Cochrane reviewers' handbook. The efficacy of CHM treatment for infertility with anovulation was evaluated by meta-analysis. There were 692 articles retrieved according to the search strategy, and 1659 participants were involved in the 15 studies that satisfied the selection criteria. All the included trials were done in China. Meta-analysis indicated that CHM significantly increased the pregnancy rate (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.50-3.88) and reduced the miscarriage rate (OR 0.2, 95% CI 0.10-0.41) compared to clomiphene. In addition, CHM also increased the ovulation rate (OR 1.55, 95% CI 1.06-2.25) and improved the cervical mucus score (OR 3.82, 95% CI 1.78-8.21) compared to clomiphene, while there were no significant difference between CHM and clomiphene combined with other medicine. CHM is effective in treating infertility with anovulation. Also, no significant adverse effects were identified for the use of CHM from the studies included in this review. However, owing to the low quality of the studies investigated, more randomized controlled trials are needed before evidence-based recommendation regarding the effectiveness and safety of CHM in the management of infertility with anovulation can be provided.

Maternal medication and herbal use and risk for hypospadias: data from the National Birth Defects Prevention Study, 1997-2007

PURPOSE

To investigate associations between maternal use of common medications and herbals during early pregnancy and risk for hypospadias in male infants.

METHODS

We used data from the National Birth Defects Prevention Study, a multi-site, population-based, case-control study. We analyzed data from 1537 infants with second-degree or third-degree isolated hypospadias and 4314 live-born male control infants without major birth defects, with estimated dates of delivery from 1997 to 2007. Exposure was reported use of prescription or over-the-counter medications or herbal products, from 1 month before to 4 months after conception. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression, adjusting for maternal age, race/ethnicity, education, pre-pregnancy body mass index, previous live births, maternal subfertility, study site, and year.

RESULTS

We assessed 64 medication and 24 herbal components. Maternal uses of most components were not associated with an increased risk of hypospadias. A new associations was observed for venlafaxine (aOR 2.4; 95%CI 1.0, 6.0) [Correction made here after initial online publication.]. The previously reported association for clomiphene citrate was confirmed (aOR 1.9; 95%CI 1.2, 3.0). Numbers were relatively small for exposure to other specific patterns of fertility agents, but elevated aORs were observed for the most common of them.

CONCLUSIONS

Overall, findings were reassuring that hypospadias is not associated with most medication components examined in this analysis. New associations will need to be confirmed in other studies. Increased risks for hypospadias associated with various fertility agents raise the possibility of confounding by underlying subfertility.

Effect of maternal age and fertility treatment on the increase in multiple births in Japan: vital statistics, 1974-2009

Background

The present study used vital-statistics data to estimate the effect of maternal age and fertility treatment on the number and rate of multiple live births in Japan from 1974 through 2009.

Methods

Japanese vital statistics published by the Ministry of Health, Labour and Welfare from 1974 to 2009 were gathered and reanalyzed with regard to maternal age class and plurality of live births. The numbers of spontaneous and iatrogenic multiple births during 1977–2009 were estimated, with the assumption that spontaneous multiple-birth rates according to maternal age class would be constant and equal to those of baseline values, ie, the means between 1974 and 1976.

Results

During the 25-year period, multiple-birth rates according to maternal age class increased after the late 1980s. This tendency was obvious in women aged 35 to 39 years. The estimated numbers of iatrogenic multiple births remained nearly constant in women aged 20 to 24 years and greatly increased in women aged 30 to 34 and 35 to 39 years. The rate (per 1000 live births) of iatrogenic multiple births gradually increased from 0.7 (1977) to 1.3 (1986), then rapidly and markedly increased from 1.3 (1986) to 11.4 (2005), and finally decreased to 8.1 (2009). The estimated maximum percentage of iatrogenic multiple births was 50.0%, in 2004 and 2005.

Conclusions

The rapid increases in Japan in the number and rate of multiples born to women older than 30 years are likely due to iatrogenic rather than spontaneous multiple births.

The effect of an increase in the rate of multiple births on low-birth-weight and preterm deliveries during 1975-2008

BACKGROUND

Despite the rapid increase in the rate of multiple births due to the growth of reproductive medicine, there have been no epidemiologic studies of the secular trends in the impact of multiple births on the rates of low-birth-weight and preterm deliveries in Japan.

METHODS

Japanese vital statistics for multiple live births were obtained from the Ministry of Health, Labour and Welfare and reanalyzed. With singletons as the reference group, an analysis was performed of secular trends in relative risk and population attributable risk percent of low-birth-weight (<2500 grams), very-low-birth-weight (<1500 grams), and extremely-low-birth-weight (<1000 grams) deliveries, using 1975-2008 vital statistics, and of preterm deliveries (ie, before 37, 32, and 28 weeks), using 1979-2008 vital statistics.

RESULTS

The rate of multiple births doubled during the past 2 decades, and about 2% of all neonates are now multiples. The population attributable risk percent tended to increase during the same period for all variables, and was approximately 20% in 2008.

CONCLUSIONS

The public health impact of the rapid increase in multiple births remains high in Japan.

The Italian National Register of infants with congenital hypothyroidism: twenty years of surveillance and study of congenital hypothyroidism

All the Italian Centres in charge of screening, diagnosis, and follow-up of infants with congenital hypothyroidism participate in the Italian National Registry of affected infants, which performs the nationwide surveillance of the disease. It was established in 1987 as a program of the Health Ministry and is coordinated by the Istituto Superiore di Sanità. The early diagnosis performed by the nationwide newborn screening programme, the prompt treatment and the appropriate clinical management of the patients carried out by the Follow-up Centres, and the surveillance of the disease performed by the National Register of infants with congenital hypothyroidism are the components of an integrated approach to the disease which has been successfully established in our country.

The aim of the Register is to monitor efficiency and effectiveness of neonatal screening, to provide disease surveillance and to allow identification of possible aetiological risk factors for the disease. During the past twenty years the active and continuous collaboration between the Register and the Italian Screening and Follow up Centres for Congenital Hypothyroidism allowed to perform a standardization of screening procedures and considerable improvements in the time at starting treatment and in the dose of therapy. Furthermore, the large amount and the high quality of information collected in the Register provided a unique opportunity for research into the disease. This because data collected in the Register are highly representative as referred to the entire Italian population with congenital hypothyroidism. The results derived from the epidemiological studies performed in these years, by using the Register database, contributed to deepen the knowledge of congenital hypothyroidism, to start identifying the most important risk factors for the disease, and to orient molecular studies aimed at identifying new genes involved in the aetiology of this condition.

Neonatal outcomes in triplet pregnancies: assisted reproduction versus spontaneous conception

AIMS

The purpose of this study is to compare neonatal outcomes of spontaneously conceived triplets with triplets conceived by assisted reproduction.

METHODS

This was a retrospective cohort study of all cases from assisted triplet pregnancies and controls from spontaneous triplet pregnancies. A total of 24 triplet pregnancies were studied: six spontaneous and 18 assisted. The following variables were evaluated in all newborns: prematurity, birth-weight, small for gestational age, birth-weight discordance, Apgar scores, major neonatal morbidity and perinatal mortality.

RESULTS

Gestational age (33+/-1 vs. 33+/-2 weeks) and birth-weight (1760+/-256 vs. 1907+/-452 g) were similar in spontaneous and assisted triplet pregnancies. There were no significant differences in the rates of small for gestational age, discordance, and major neonatal morbidity. In the assisted reproduction group only the following cases were recorded: 1 surgically treated patent ductus arteriosus, 1 feto-fetal transfusion syndrome, 2 grade II intraventricular hemorrhage, 1 Cri du Chat syndrome and 1 stillbirth with malformations.

CONCLUSIONS

This study is unable to assess the influence of assisted reproduction on the neonatal outcomes of triplet pregnancies. However, the results suggest that the incidence of major neonatal morbidity, especially malformations, might increase due to assisted reproduction. This finding requires further confirmation.

High risk of congenital hypothyroidism in multiple pregnancies

CONTEXT

In Italy, the surveillance of congenital hypothyroidism (CH) is performed by the Italian National Registry of Infants with CH (INRICH). Up to now, about 3600 infants with CH are recorded in the INRICH, and a high number of twins are included.

OBJECTIVE

Our objective was to estimate the risk of CH in multiple and single deliveries and to compare neonatal features of CH twins with twins from the general population.

DESIGN

The Italian population of CH infants recorded in the INRICH from 1989-2000 was investigated.

RESULTS

A more than 3-fold higher frequency of twins was found in the CH population than in the general population, and for the first time, it was possible to estimate the CH incidence in multiple (10.1 in 10,000) and single deliveries (3.2 in 10,000 live births). Significantly higher frequencies of in situ gland as well as lower TSH mean level at screening were found in twin than in singleton CH babies. The concordance rate for permanent CH was very low (4.3%) and due to only three concordant couples. However, a high recurrence risk for CH was estimated in siblings of affected babies recorded in the INRICH, including twins considered as siblings.

CONCLUSIONS

The high CH incidence observed in twins is worthy of interest for the high number of induced pregnancies in Italy as well as in other Western countries. Moreover, the low concordance rate for CH among twins together with a high recurrence risk for the disease among siblings indicates that environmental risk factors may act as a trigger on a susceptible genetic background in the etiology of the disease.

Twin gestation in older women: antepartum, intrapartum complications, and perinatal outcomes

OBJECTIVE

The aim of this study is to present pregnancy and perinatal outcomes of twin gestations in older women and compare them with that for younger women.

STUDY DESIGN

We conducted a retrospective cohort study of twin pregnancies in our department between 1988 and 2003. The women were classified into two groups by maternal age: women of age 35 years and older (study group) and women less than 35 years (control group). Population characteristics, complications during pregnancy and delivery, and neonatal outcomes were assessed. The Student's t-test, chi2 test, Fisher exact test, and binary logistic regression analysis were used to examine the relationship between maternal age and the different variables.

RESULTS

A total of 238 twin pregnancies were enrolled (study group, 57 women; control group, 181 women). Spontaneous conceptions were significantly higher in the control group (P < 0.001), while conceptions after in vitro fertilization (IVF) were significantly higher in study group (P < 0.001). Mean figures of gestational age at delivery and birth weight for the older group did not differ significantly from the younger group. Although the antepartum and intrapartum complications were more common in the study group, they were not statistically significant compared to the control group. This was also true for the perinatal outcomes. Only the very low birth weight (VLBW < 1,500 g) rate was significantly higher in the study group. The number of perinatal deaths was similar on comparison by maternal age.

CONCLUSIONS

Based on our study, advanced maternal age at twin gestation does not seem to affect significantly pregnancy complications and perinatal outcomes. VLBW was the only unfavorable perinatal outcome related to advanced maternal age.

Use of a prediction model for high-order multiple implantation after ovarian stimulation with gonadotropins

OBJECTIVE

To determine prospectively the effectiveness in clinical practice of a prediction model for high-order multiple pregnancies (HOMP) (triplets or more).

DESIGN

Prospective study.

SETTING

University teaching hospital.

PATIENT(S)

Eight hundred forty-nine consecutive infertile patients undergoing a total of 1,542 treatment cycles.

INTERVENTION(S)

Gonadotropin ovarian stimulation or induction of ovulation without IVF MAIN OUTCOME MEASURE(S): Observed and predicted overall pregnancy rates and the incidence of HOMP.

RESULT(S)

The use of the prediction model (implying cancellation of all cycles at high risk for HOMP) would result in an 8% (95% confidence interval, 6.8%-9.2%) reduction of overall pregnancy rate but also in a 285% (95% CI, 279%-291%) reduction of HOMP.

CONCLUSION(S)

By using our prediction model, it was possible to maintain a low risk of HOMP with a good pregnancy rate in patients receiving gonadotropin ovarian stimulation or induction of ovulation without IVF.

Twin frequency and industrial pollution in different regions of Hesse, Germany

AIMS

To investigate whether twinning occurs more frequently in residents in the vicinity of a toxic waste incinerator (TWI).

METHODS

Within a longitudinal environmental study that addressed child health second grade school children and their parents were recruited. The proportion of twinning in the TWI region was compared with two comparison areas. In a second confirmatory investigation, birth records for the years 1994-97 from the Hessian Perinatal Survey (HEPS) were accessed to determine whether the incidence of twinning was higher in regions around the TWI compared to adjacent reference areas.

RESULTS

In the environmental study, 61.5% of the children and 95% of their mothers participated. In mothers, twinning was 5.3% in the TWI region compared to 1.6% and 2.3% in the comparison regions. The proportion of mothers with fertility assessment/treatment was 5.7%, 8.3%, and 0% respectively. The prevalence of twinning was not significantly higher (4.5%) in mothers with treatment compared to mothers without (3.7%). From the HEPS, data of 20 603 births was analysed. The incidence of twins was significantly higher in areas which surround the TWI and other industries (1.4-1.6 per 100 births) compared to births in reference areas (0.8 per 100).

CONCLUSIONS

Twinning rates may be associated with exposure to industrial pollution. Future environmental health studies that consider multiple births as an outcome are warranted. These should also investigate whether the incidence of monozygotic or dizygotic twinning may be associated with industrial pollution.

Childhood tumor risk after treatment with ovulation-stimulating drugs

OBJECTIVE

To assess childhood cancer risk among children conceived following the use of ovulation-stimulating drugs.

DESIGN

Record linkage study.

SETTING

Infertility patients and their offspring as identified through medical records.

PATIENT(S)

Cohort of 30,364 Danish women evaluated for infertility beginning in the early 1960s.

MAIN OUTCOME MEASURE(S)

Standardized incidence ratios (SIRs) compared cancer incidence in the children to the Danish population. Case-cohort techniques calculated rate ratios (RRs) according to prior maternal drug exposures.

RESULT(S)

A total of 51 cancers were identified among the study children, resulting in an SIR of 1.14 (95% confidence interval [CI] 0.8-1.5). Usage of any fertility drug was associated with an RR of 0.82 (95% CI 0.4-1.6) and clomiphene citrate with an RR of 0.77 (95% CI 0.4-1.6). Tumors occurring early in life and nonhematopoietic malignancies (including neuroblastomas) were not associated with drug usage. Nonsignificant elevations in the risk of cancers occurring later in life, especially childhood hematopoietic malignancies (RR for use of any ovulation-stimulating drugs of 2.30, 95% CI 0.8-6.6), may have been related to underlying reasons for medication usage.

CONCLUSION(S)

Although the findings of this study are reassuring, additional adequately powered studies should continue monitoring the effects of ovulation-stimulating drugs on specific tumors, including hematopoietic malignancies.

Gonadotrophin ovarian stimulation and intrauterine insemination for unexplained infertility

Over the past 15 years, there has been a marked increase in the use of ovulation induction and intrauterine insemination (IUI) for the treatment of unexplained infertility. However, although ovulation induction and IUI have rapidly gained popularity, clinical use is based largely on practical experience rather than on well-designed scientific studies. This article summarizes the evidence in this area. Despite clinical heterogeneity and different methodological qualities of the trials, it can be concluded that ovulation induction significantly improves the probability of conception in couples with unexplained infertility, particularly when associated with IUI. It is remarkable, though, that there has been only one large-scale, randomized trial of ovulation induction plus IUI in the treatment of unexplained infertility in which one of the study arms is an untreated control group. For couples requiring treatment, the complication rate must be minimized, particularly the occurrence of high-order multiple pregnancy. Evaluation of the effectiveness and safety of low-dose gonadotrophin administration in patients with unexplained infertility is limited and further studies are warranted.

Triplets and quadruplets in Switzerland: comparison with singletons, and evolution over the last decade

AIMS

Main objectives were 1) to determine the incidence of higher multiple births from 1995 to 1998 in Switzerland, and 2) to evaluate neonatal mortality and morbidity. Secondary objectives were 3) to compare the results with those of matched singletons, and 4) to compare the present data to the first Swiss study (1985-1988).

METHODS

Retrospective analysis of maternal and neonatal data obtained from all Swiss hospitals.

RESULTS

The incidence of triplet births was 1/3247 and that of quadruplet births 1/81,186. The median gestational age was 32 5/7 weeks for triplets, and 28 6/7 weeks for quadruplets. The median birth weight was 1665 g for triplets and 1076 g for quadruplets. Perinatal mortality was 6% for triplets and 19% for quadruplets. Respiratory distress syndrome was the major morbidity as diagnosed in 52% of triplets and 81% of quadruplets. A comparison of triplets with matched singletons showed no significant differences in morbidity and mortality. Compared with the first Swiss study, the mortality rate decreased, while the incidence of triplets increased but decreased for quadruplets.

CONCLUSION

The incidence of higher-order multiple births in Switzerland dropped for quadruplets in the last decade but has increased for triplets. The mortality and morbidity of triplets is comparable to that of singletons with a similar gestational age.

Rates of twinning before and after fortification of foods in the US with folic acid, Texas, 1996 to 1998

Several investigators have reported a 40% increase in the prevalence of twinning among women who have taken folic acid or multivitamins containing folic acid at the time of conception. Given that infant morbidity and mortality are greatly increased among twins, such a large increase in twinning could have serious implications. We undertook this study to determine if US fortification of enriched cereal-grain products with folic acid was associated with an unexpected increase in the prevalence of twinning in the state of Texas. We examined 1 003 207 deliveries conceived in Texas, between 1 January 1996 and 31 December 1998. We compared the prevalence of twin deliveries conceived before, during and after fortification with folic acid, mandated to begin on 1 January 1998. Comparing pregnancies conceived in 1997 with those conceived in 1996, we observed a 2.4% yearly increase in twinning, 1.024 [0.98, 1.07]. Comparing pregnancies conceived in 1998 with those conceived in 1997, we observed a 4.6% yearly increase in twinning, 1.046 [1.00, 1.09]. These increases were adjusted for maternal age, race, education, parity and season of conception. The size and pattern of these increases are consistent with the ongoing increase in twinning of 1-4% per year which began in the US prior to fortification.

Multiple gestations: some public policy issues

Multiple gestations, or multifetal pregnancies, raise a number of significant policy questions concerning the well being of women and the well being of the children fetuses might become. Important questions for feminists pertain not only to multifetal pregnancy itself, but also to the medical interventions associated with these pregnancies. In this paper, we address the questions of how many embryos should be transferred in assisted reproduction, how many fetuses should remain in a multiple gestation, who should make these decisions, and the need to protect women from overexposure to exogenous hormones. Although we focus on assisted reproduction in the United States, we believe that our suggestions are applicable to other countries where the technology is comparable.

Risk factors for high-order multiple implantation after ovarian stimulation with gonadotrophins: evidence from a large series of 1878 consecutive pregnancies in a single centre

BACKGROUND

High-order multiple pregnancies (triplets or more) have a large adverse impact on perinatal morbidity and mortality as well as important economic consequences. Most triplets and higher births are due to ovulation induction alone or in combination with intrauterine insemination (IUI) rather than to in-vitro fertilization (IVF). The present investigation was undertaken to determine whether there were specific variables that related to patient clinical characteristics (age of the woman, duration of infertility, type of infertility, body mass index, basal FSH and LH concentrations), treatment characteristics (initial dose of gonadotrophins, total dose of gonadotrophins administered, number of days of ovarian stimulation, insemination procedure, number of spermatozoa inseminated in patients undergoing IUI, type of luteal support), and ovarian response (oestradiol serum concentrations, number and size of follicles) that might be associated with the occurrence of high-order multiple implantation in order to develop a prediction model.

METHODS

This study employed univariate, multivariate and receiver-operating characteristic (ROC) analysis of a large series of 1878 consecutive pregnancies obtained in cycles stimulated with gonadotrophins. Of them, 1771 (94.3%) were low-order pregnancies (1477 singletons and 294 pairs of twins) and 107 (5.7%) were high-order pregnancies.

RESULTS

Predictive variables in the multivariate analysis were age of the woman, serum oestradiol concentrations and number of follicles >10 mm on the day of HCG injection. Stratification of the number of follicles into three categories (1 to 3, 4 to 5, and >5 follicles respectively), peak serum oestradiol and woman's age according to the ROC curves, showed that the risk of high-order multiple implantation correlated significantly with increasing total number of follicles and was significantly increased in women with a serum oestradiol >862 pg/ml and aged < or =32 years.

CONCLUSIONS

This three-variable model can help to identify patients at high-risk for high-order multiple pregnancy in ovulation induction cycles.

Follicular development and hormone concentrations following recombinant FSH administration for anovulation associated with polycystic ovarian syndrome: prospective, randomized comparison between low-dose step-up and modified step-down regimens

The present study compared ovarian performance and hormone concentrations, after ovulation induction, in polycystic ovarian syndrome (PCOS) patients, using recombinant human FSH (rhFSH) in low-dose step-up and modified step-down regimens. Twenty-six women with clomiphene citrate-resistant chronic anovulatory infertility were treated with rhFSH in two consecutive cycles according to two different low-dose regimens: (i) the classic chronic low-dose step-up protocol, the starting dose being 75 IU; (ii) a modified step-down protocol where the starting dose was 300 IU followed by 3 days free of treatment, then rhFSH 75 IU daily was given and stepwise dose increments were performed exactly the same as in the step-up method. Each woman received both treatment approaches, in a randomized order, with an interval of > or = 1 month between treatments. The total number of follicles that were > 10, > 14 and > 17 mm in diameter on the day of human chorionic gonadotrophin (HCG) administration, and thus cycles with HCG cancelled, were significantly increased with the step-up approach. The total number of rhFSH ampoules tended to be higher with the step-down schedule despite the fact that both the mean duration of treatment and the threshold dose were similar with the two low-dose approaches. A physiological step-down approach for ovulation induction in PCOS patients may be more appropriate in order to avoid multifollicular cycles than the step-up approach.

Neonatal outcome of spontaneous and assisted twin pregnancies

OBJECTIVES

Over the last 10 years, diffusion of assisted reproduction techniques (ovarian stimulation, IVF, GIFT) has led to an increased incidence of multiple pregnancies and consequently, of the related obstetric-neonatal problems. In this study, multiple births have been studied, with particular reference to the twin births occurring in the Gemelli hospital, Rome. The hospital is also a reference centre for obstetric pathologies and infertility treatment. In particular, attention has been focused on neonatal outcome, comparing twins born from spontaneous and assisted pregnancies.

STUDY DESIGN

228 neonates from spontaneous twin pregnancies and 32 from assisted twin pregnancies were taken into consideration with regard to: premature birth, low birth-weight, intrauterine growth retardation, weight discordance, Apgar score, major neonatal diseases, and mortality.

RESULTS

Results showed a significant higher incidence of prematurity and low birth-weight, as well as a significant lower gestational age, occurring more frequently in twins resulting from assisted pregnancies than in twins from spontaneous pregnancies. Furthermore, the incidence of severe depression at birth and respiratory disease was significantly higher in twins from assisted pregnancies than in those from spontaneous pregnancies, despite similar gestational age and birth-weight.

Recombinant human follicle-stimulating hormone for ovulation induction in polycystic ovary syndrome: a prospective, randomized trial of two starting doses in a chronic low-dose step-up protocol

PURPOSE

The aim was to compare the follicular response to 37.5 and 50 IU of recombinant follicle-stimulating hormone (FSH) as starting doses for ovulation induction in patients with polycystic ovary syndrome (PCOS).

METHODS

Prospective, randomized, crossover study including 15 women with clomiphene citrate-resistant chronic anovulatory infertility. Patients were treated with subcutaneous recombinant FSH at starting doses of 37.5 IU and 50 IU, respectively, according to a low-dose step-up protocol. Each woman received both treatments, in a randomized order, with an interval of > or = 1 month between treatments.

RESULTS

All treatment cycles were ovulatory after an appropriate follicular response and hormone levels were similar with both treatments, although the total quantity of FSH required and the mean daily dose required to induce identical follicular development were significantly lower with a starting dose of 37.5 IU FSH. The mean duration of treatment to achieve ovulation was approximately 13 days with both treatments but treatment periods > or = 20 days were required in some patients.

CONCLUSIONS

In women with PCOS, a starting dose of 37.5 IU recombinant FSH may be adequate to induce follicular growth. However, the use of low starting doses may result in some cases in increased treatment periods and need for monitoring.