OBSTETRIC AND PERINATAL OUTCOMES OF NATURAL CYCLE VS. ARTIFICIAL CYCLE FROZEN EMBRYO TRANSFERS

Abstract STUDY QUESTION Does the endometrial preparation protocol for frozen embryo transfer (FET) have an impact on perinatal outcomes? SUMMARY ANSWER Singleton newborns from conceptions after an artificial FET cycle had a higher risk of being large for gestational age (LGA). WHAT IS KNOWN ALREADY Most previous studies have concentrated on the clinical pregnancy, miscarriage and live birth rates of different endometrial preparation protocols for FET. However, the impacts of these cycle regimens on perinatal outcomes including birthweight, gestational age (GA) and related outcomes require more investigation. STUDY DESIGN, SIZE, DURATION We retrospectively analysed all singletons conceived by women who underwent non-donor FET cycles between July 2014 and July 2017. The propensity score matching (PSM) method using nearest neighbour matching at a proportion of 1:1 was established to adjust for factors that influence the probability of receiving different FET cycle regimens. The main outcomes of the study included birthweight and its related outcomes, Z-score, low birthweight (LBW, <2500 g), small for gestational age (SGA, ≤10th percentile of referential birthweight), LGA (≥90th percentile of referential birthweight) and macrosomia (birthweight >4000 g). The study outcomes also included GA at birth, preterm delivery (<37 weeks), very preterm delivery (<32 weeks), very low birthweight (VLBW, <1500 g), term LBW (at 37 weeks of gestation or greater) and preterm LBW (at <37 weeks of gestation). PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 9267 cycles with live-born singletons were included in the analysis in our centre between July 2014 and July 2017. Of these, 2224, 4299 and 2744 live-born singletons were conceived by natural cycle FET, stimulated cycle FET and artificial cycle FET, respectively. After PSM, 1947 cycles of natural cycle FET versus stimulated cycle FET, 1682 cycles of stimulated cycle FET versus artificial cycle FET and 2333 cycles of natural cycle FET versus artificial cycle FET were included in the analysis. MAIN RESULTS AND THE ROLE OF CHANCE A higher mean birthweight and Z-score were observed in the artificial cycle FET group than in the stimulated cycle FET group (P = 0.005; P = 0.004, respectively). Singleton newborns conceived after artificial cycle FET were more likely to be LGA than those born after natural cycle FET or stimulated cycle FET (19.92% versus 16.94% and 19.29% versus 16.12%, respectively). The adjusted ORs (95% CIs) were 1.25 (1.05, 1.49) for artificial cycle FET compared with natural cycle FET (P = 0.014) and 1.26 (1.08, 1.46) for artificial cycle FET compared with stimulated cycle FET (P = 0.003). Newborns conceived after stimulated cycle FET had a lower mean GA at birth and a lower mean birthweight than those born after natural cycle FET or artificial cycle FET. The stimulated cycle FET group had lower adjusted odds of being macrosomia than the natural cycle FET group. No significant differences between natural cycle FET and stimulated cycle FET were found for any of the other outcomes. LIMITATIONS, REASONS FOR CAUTION This study had the disadvantage of being retrospective, and some cases were excluded due to missing data. The original allocation process was not randomized, which may have introduced bias. We have chosen not to account for multiple comparisons in our statistical analysis. WIDER IMPLICATIONS OF THE FINDINGS LGA can have long-term consequences in terms of risk for disease, which means that the influences of artificial cycle FET are of clinical significance and deserve more attention. Furthermore, these findings are critical for clinicians to be able to make an informed decision when choosing an endometrial preparation method. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by grants from the National Natural Science Foundation of China (NSFC) (31770989 to Y.W.) and the Shanghai Ninth People’s Hospital Foundation of China (JYLJ030 to Y.W.). None of the authors have any conflicts of interest to declare.

Download Full-text

THE EFFECT OF ANTIBIOTIC ADMINISTRATION ON NATURAL CYCLE FROZEN EMBRYO TRANSFERS

Fertility and Sterility ◽

10.1016/j.fertnstert.2020.08.826 ◽

2020 ◽

Vol 114 (3) ◽

pp. e302

Author(s):

Jasmyn K. Johal ◽

Isabel Beshar ◽

Brindha Bavan ◽

Amin A. Milki

Keyword(s):

Antibiotic Administration ◽

Natural Cycle ◽

Frozen Embryo Transfers

Download Full-text

P26.03: Perinatal outcomes in singleton pregnancies conceived by natural cycle as compared with conventional IVF and spontaneously conceived pregnancies

Ultrasound in Obstetrics and Gynecology ◽

10.1002/uog.18262 ◽

2017 ◽

Vol 50 ◽

pp. 239-239

Author(s):

H. Ayuso ◽

G. Casals ◽

B. Valenzuela-Alcaraz ◽

D. Manau ◽

J. Peñarrubia ◽

...

Keyword(s):

Perinatal Outcomes ◽

Natural Cycle ◽

Singleton Pregnancies

Download Full-text

BODY MASS INDEX DOES NOT AFFECT NATURAL CYCLE FROZEN EMBRYO TRANSFERS

Fertility and Sterility ◽

10.1016/j.fertnstert.2021.07.660 ◽

2021 ◽

Vol 116 (3) ◽

pp. e245-e246

Author(s):

Isabel Beshar ◽

Brindha Bavan ◽

Amin A. Milki

Keyword(s):

Body Mass Index ◽

Body Mass ◽

Natural Cycle ◽

Frozen Embryo Transfers

Download Full-text

Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

BMC Medicine ◽

10.1186/s12916-019-1429-z ◽

2019 ◽

Vol 17 (1) ◽

Cited By ~ 3

Author(s):

Andrew D. A. C. Smith ◽

Kate Tilling ◽

Deborah A. Lawlor ◽

Scott M. Nelson

Keyword(s):

Embryo Transfer ◽

Live Birth ◽

Lower Risk ◽

Rate Ratio ◽

Perinatal Outcomes ◽

In Vitro Fertilisation ◽

Birth Rates ◽

Live Birth Rates ◽

Frozen Embryo Transfers

Abstract Background It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred. Methods In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LBW < 2.5 kg), preterm birth (< 37 weeks), macrosomia (> 4 kg), small for gestational age (SGA < 10th centile), and large for gestational age (LGA > 90th centile) for a given ovarian stimulation cycle accounting for all embryo transfers. Results We assessed 202,968 women undergoing 337,148 ovarian stimulation cycles and 399,896 embryo transfer procedures. Live birth rates were similar in unadjusted analyses for segmented and non-segmented cycles (rate ratio 1.05, 95% CI 1.02–1.08) but lower in segmented cycles when adjusted for age, cycle number, cause of infertility, and ovarian response (rate ratio 0.80, 95% CI 0.78–0.83). Segmented cycles were associated with increased risk of macrosomia (adjusted risk ratio 1.72, 95% CI 1.55–1.92) and LGA (1.51, 1.38–1.66) but lower risk of LBW (0.71, 0.65–0.78) and SGA (0.64, 0.56–0.72). With adjustment for blastocyst/cleavage-stage embryo transfer in those with data on this (329,621 cycles), results were not notably changed. Similar results were observed comparing segmented to non-segmented within 3261 women who had both and when analyses were repeated excluding multiple embryo cycles and multiple pregnancies. When analyses were restricted to women with a single embryo transfer, the transfer of a frozen-thawed embryo in a segmented cycles was no longer associated with a lower risk of LBW (0.97, 0.71–1.33) or SGA (0.84, 0.61–1.15), but the risk of macrosomia (1.74, 1.39–2.20) and LGA (1.49, 1.20–1.86) persisted. When the analyses for perinatal outcomes were further restricted to solely frozen embryo transfers, there was no strong statistical evidence for associations. Conclusions Widespread application of segmentation and freezing of all embryos to unselected patient populations may be associated with lower cumulative live birth rates and should be restricted to those with a clinical indication.

Download Full-text