Increased Live Birth Rate in Twin Pregnancies Resulting From Embryo Assistance

Can early ultrasonography explain the lower miscarriage rates in twin as compared to singleton pregnancies following assisted reproduction?

Objective:

To compare first trimester 2D conventional and 3D power Doppler angiography measures in twins and singletons following assisted reproduction.

Methods:

We prospectively evaluated 50 singleton and 47 twin pregnancies that eventually ended in live births. Patients were recruited from a single assisted reproductive technology (ART) center with standard treatment protocols. Obstetric ultrasound was performed at 8–9 weeks +6 days. Intervillous flow, uteroplacental circulation and uterine artery pulsatility (PI) and resistance index (RI) using two-dimensional (2D) ultrasound examination were evaluated. Using three-dimensional (3D) power Doppler angiography, placental volume and the 3D power Doppler indices from the intervillous and uteroplacental circulation were calculated.

Results:

Demographic and cycle characteristics were similar in mothers of singletons and twins. Placental volume was significantly (1.6-fold) larger in twins. Vascular density and blood perfusion in the intervillous space were lower in twins. The comparison of the other parameters did not show significant differences between singletons and twins.

Conclusion:

The data confirm the larger placental volume in twins, denoting a probable higher production of placental hormones that would support an early twin pregnancy. The lower vascular density and blood perfusion in the intervillous space in twins may also confer a reproductive advantage to them.

First-trimester bleeding and twin pregnancy outcomes after in vitro fertilization

OBJECTIVE

To examine the association between first-trimester bleeding and live-birth rates in twin pregnancies conceived with in vitro fertilization (IVF).

DESIGN

Retrospective cohort study.

SETTING

Academic infertility practice.

PATIENT(S)

Women with two gestational sacs on first-trimester ultrasound after transfer of fresh embryos derived from autologous oocytes between January 1, 1999, and December 31, 2010.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live-birth rate.

RESULT(S)

Sixty-five women reported vaginal bleeding, and 288 did not. The baseline characteristics were similar between the two groups, except for an increased prevalence of subchorionic hematoma in women with first-trimester vaginal bleeding (26.2% vs. 1.7%). Live-birth rates were similar between women with bleeding and those with no bleeding (87.7% vs. 91.7%, adjusted odds ratio [OR] 0.73; 95% confidence interval [CI], 0.31-1.73). Two hundred eighty-eight women gave birth to live twins. Among the women who delivered twins, those with first-trimester bleeding had an increased risk of low birth weight of at least one twin (75.0% vs. 59.7%). The association between bleeding and low birth weight persisted after controlling for possible confounders with logistic regression (adjusted OR 2.33, 95% CI, 1.14-4.74).

CONCLUSION(S)

Live-birth rates are high in IVF twin gestations, regardless of the presence of first-trimester bleeding. Among women giving birth to IVF twins, however, first-trimester bleeding is associated with increased odds of low birth weight.

Two consecutive singleton pregnancies versus one twins pregnancy as preferred outcome of in vitro fertilization for mothers and infants: a retrospective case-control study

OBJECTIVE

Many infertile couples request a multiple embryo transfer because they desire more than one child. Based on this consideration, the current study aimed to compare the reproductive and perinatal outcomes of two consecutive singleton pregnancies versus one twin pregnancy in a large cohort of in vitro fertilization (IVF) patients.

RESEARCH DESIGN AND METHODS

Retrospective analysis of data from patients with clinical twin pregnancy after IVF fresh cycles and from patients with two consecutive IVF fresh cycles and clinical singleton pregnancy.

MAIN OUTCOME MEASURES

Miscarriage rate, delivery rate, gestational age at birth, neonatal birth weight, and perinatal complications. A sub-analysis of data according to vanishing twin syndrome (VTS) was also performed.

RESULTS

A total of 18,703 autologous fresh cycles were analyzed. One hundred seven patients had two consecutive singleton clinical pregnancies, whereas one clinical twin pregnancy occurred in 641 women. In patients who had two consecutive singleton clinical pregnancies the rates of overall pregnancies lost (odds ratio [OR] 4.9, 95% confidence interval [CI] 3.4, 6.9) and live births (OR 0.2, 95% CI 0.1, 0.3) were, respectively, higher and lower when compared to patients who had one clinical twin pregnancy. That data did not change after sub-analysis for VTS. The overall risk of perinatal complications was significantly higher in patients who had one twin delivery rather than patients who had two consecutive singleton deliveries (OR 31.8, 95% CI 14.1, 71.5). No difference between groups was detected in terms of intrauterine/neonatal deaths, perinatal mortality and neonatal intensive care unit admission. Data did not change after adjusting for confounders.

CONCLUSIONS

When compared with two consecutive singleton pregnancies, twin pregnancies are characterized by higher success rates but worse perinatal outcomes irrespectively of VTS. Well designed prospective controlled studies are needed to confirm or rebut current retrospective findings.

Economic evaluation of highly purified human menopausal gonadotropin versus recombinant human follicle-stimulating hormone in fresh and frozen in vitro fertilization/intracytoplasmic sperm-injection cycles in Sweden

Gonadotropin-releasing hormone-analog type, fertilization method, and number of embryos available for cryopreservation should be incorporated into economic evaluations of highly purified human menopausal gonadotropin (HP-hMG) and recombinant human follicle-stimulating hormone (r-hFSH), as they may affect treatment costs. We searched for randomized trials and meta-analyses comparing HP-hMG and r-hFSH. Meta-analysis showed no significant difference in live births (odds ratio 0.82, 95% confidence interval [CI] 0.66–1.01), but a greater number of oocytes with r-hFSH (mean difference [MD] 1.96, 95% CI 1.02–2.90). Using a cost-minimization model for Sweden, accounting for embryo availability, survival following thawing, and patient dropout, we simulated patients individually for up to three cycles. R-hFSH was found to be cost-saving, at 2,767 kr (95% CI 1,580–4,057) per patient (€315 or $411); baseline savings were 6.43% of the total HP-hMG cost. In fresh cycles only, the savings for r-hFSH were 1,752 kr (95% CI 48–3,658) per patient (€200 or $260). In univariate sensitivity analyses, savings were obtained until the price of r-hFSH increased by 30% or the dosage of HP-hMG decreased by 38%–62% of baseline value. In probabilistic sensitivity analysis, r-hFSH was cost-saving in 100% of the simulated cohort per patient and in 85% per live birth; the respective percentages for fresh cycles only were 97.3% and 73.1%. In conclusion, a greater number of oocytes with r-hFSH allows for more frozen embryo transfers, thereby reducing overall treatment cost.