A retrospective analysis of placentas from twin pregnancies derived from assisted reproductive technology

Pregnancy and neonatal outcomes of monozygotic twins resulting from assisted reproductive technology: a 10-year retrospective study

BACKGROUND

Monozygotic twins (MZTs) are associated with high risks of maternal and fetal complications. Even with the widely used elective single embryo transfer (SET), the risk of MZTs following assisted reproductive technology (ART) treatments remains. However, most studies of MZTs focused on the relevant etiology, with few studies describing pregnancy and neonatal outcomes.

METHODS

This retrospective cohort study included 19,081 SET cycles resulting from in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), preimplantation genetic testing (PGT) and testicular sperm aspiration (TESA) performed between January 2010 and July 2020 in a single university-based center. A total of 187 MZTs were included in this investigation. The main outcome measures were the incidence, pregnancy and neonatal outcomes of MZTs. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy loss.

RESULTS

The overall rate of MZTs from ART treatment in SET cycles was 0.98%. No significant difference was found in the incidence of MZTs among the four groups (p = 0.259). The live birth rate of MZTs in the ICSI group (88.5%) was significantly more favorable than in the IVF, PGT and TESA groups (60.5%, 77.2% and 80%, respectively). IVF resulted in a significantly increased risk of pregnancy loss (39.4%) and early miscarriage (29.5%) in MZT pregnancies compared to ICSI (11.4%, 8.5%), PGT (22.7%, 16.6%) and TESA (20%, 13.3%). The total rate of twin-to-twin transfusion syndrome (TTTS) in MZTs was 2.7% (5/187); however, the TESA group had the highest rate at 20% and was significantly higher than the PGT group (p = 0.005). The four ART groups had no significant effect on the occurrence of congenital abnormalities or other neonatal outcomes in newborns from MZT pregnancies. Multivariate logistic regression analysis revealed that infertility duration, cause of infertility, the total dose of Gn used, history of miscarriages, and the number of miscarriages were not related to the risk of pregnancy loss (p > 0.05).

CONCLUSIONS

The rate of MZTs was similar among the four ART groups. The pregnancy loss and the early miscarriage rate of MZTs was increased in IVF patients. Neither the cause of infertility nor the history of miscarriage was correlated with the risk of pregnancy loss. MZTs in the TESA group had a higher risk of TTTS, placental effects influenced by sperm and paternally expressed genes may play a role. However, due to the small total number, studies with larger sample sizes are still needed to validate these result. Pregnancy and neonatal outcomes of MZTs after PGT treatment seem to be reassuring but the duration of the study was short, and long-term follow-up of the children is needed.

Adverse pregnancy, birth, and infant outcomes in twins: effects of maternal fertility status and infant gender combinations; the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

It is unknown whether the risk of adverse outcomes in twin pregnancies among subfertile women, conceived with and without in vitro fertilization, differs from those conceived spontaneously.

OBJECTIVE

We sought to evaluate the effects of fertility status on adverse perinatal outcomes in twin pregnancies on a population basis.

STUDY DESIGN

All twin live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004 through 2010 were linked to hospital discharge records, vital records, and in vitro fertilization cycles. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile, and by twin pair genders (all, like, unlike). Women whose births linked to in vitro fertilization cycles were classified as in vitro fertilization; those with indicators of subfertility but without in vitro fertilization treatment were classified as subfertile; all others were classified as fertile. Risks of 6 adverse pregnancy outcomes (gestational diabetes, pregnancy hypertension, uterine bleeding, placental complications [placenta abruptio, placenta previa, and vasa previa], prenatal hospitalizations, and primary cesarean) and 9 adverse infant outcomes (very low birthweight, low birthweight, small-for-gestation birthweight, large-for-gestation birthweight, very preterm [<32 weeks], preterm, birth defects, neonatal death, and infant death) were modeled by fertility status with the fertile group as reference, using multivariate log binomial regression and reported as adjusted relative risk ratios and 95% confidence intervals.

RESULTS

The study population included 10,352 women with twin pregnancies (6090 fertile, 724 subfertile, and 3538 in vitro fertilization). Among all twins, the risks for all 6 adverse pregnancy outcomes were significantly increased for the subfertile and in vitro fertilization groups, with highest risks for uterine bleeding (adjusted relative risk ratios, 1.92 and 2.58, respectively) and placental complications (adjusted relative risk ratios, 2.07 and 1.83, respectively). Among all twins, the risks for those born to subfertile women were significantly increased for very preterm birth and neonatal and infant death (adjusted relative risk ratios, 1.36, 1.89, and 1.87, respectively). Risks were significantly increased among in vitro fertilization twins for very preterm birth, preterm birth, and birth defects (adjusted relative risk ratios, 1.28, 1.07, and 1.26, respectively).

CONCLUSION

Risks of all maternal and most infant adverse outcomes were increased for subfertile and in vitro fertilization twins. Among all twins, the highest risks were for uterine bleeding and placental complications for the subfertile and in vitro fertilization groups, and neonatal and infant death in the subfertile group. These findings provide further evidence supporting single embryo transfer and more cautious use of ovulation induction.

Obstetric and Perinatal Outcomes of Dichorionic Twin Pregnancies According to Methods of Conception: Spontaneous Versus In-Vitro Fertilization

We have observed the inconsistent findings from various studies on twin pregnancy outcomes obtained by assisted reproductive technology and spontaneous conception. In most studies, however, the concrete chorionicity, regarded as a confounding factor for predicting the perinatal outcomes of twin pregnancies, has not been determined. The purpose of this study was to compare obstetric and perinatal outcomes of only the dichorionic twin pregnancies according to the methods of conception: spontaneous and in-vitro fertilization (IVF). The twin pairs with dichorionicity reported from 1995 to 2008 were investigated and we divided them into two groups which consisted of 286 and 134 twins by spontaneous conception and IVF, respectively. Odds ratios for associations between IVF and pregnancy outcomes were analyzed after adjustment for maternal age and parity. There were no risk differences between the two groups regarding the obstetric complications, which include preterm delivery, preterm labor, preterm premature rupture of membranes, preeclampsia, placenta previa, and abruption. Any differences were not shown in the two groups for the risk estimates of perinatal outcomes, such as low birthweight, very low birthweight, small for gestational age, Apgar scores of < 7 at 5 minutes, discordance in birthweights, congenital anomalies and mortality. However, twins conceived after IVF were less likely to be admitted to the neonatal intensive care unit than those conceived spontaneously (adjusted OR 0.488; 95% confidence interval 0.261–0.910). In the cases of dichorionic twins, IVF may not be associated with adverse perinatal and obstetric outcomes compared with spontaneous conception.

Maternal morbidity and infant death in twin vs triplet and quadruplet pregnancies

OBJECTIVE

The purpose of this study was to calculate nationally representative, population-based estimates of maternal and neonatal risks in triplet and quadruplet pregnancies compared with twin pregnancies.

STUDY DESIGN

The study population included 316,696 twin, 12,193 triplet, and 778 quadruplet pregnancies from the 1995-2000 Matched Multiple Birth Data Set. Adjusted odds ratios (AORs) and 95% CIs estimated the risk of complications and were controlled for maternal age, race, parity, and smoking status.

RESULTS

Compared with mothers of twins, mothers of triplets and quadruplets were more likely to be diagnosed with preterm premature rupture of membranes (AORs, 1.53, 1.74, respectively), pregnancy-associated hypertension (AORs, 1.22, 1.27), and excessive bleeding (AORs, 1.50, 2.22), to require tocolysis (AORs, 2.85, 5.03), and to be delivered by cesarean (AORs, 6.55, 7.38) at < 29 weeks of gestation (AORs, 3.76, 7.96), and to have > or = 1 infants die (AORs, 3.02, 4.07).

CONCLUSION

Triplet and quadruplet pregnancies have significantly higher risks than twin pregnancies for most maternal and neonatal complications. Maternal anthropometric, nutritional, and previous reproductive factors may be particularly important in the reduction of these excess risks and improvement of outcomes in multiple births.