Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study from the CoNARTaS group

UB Wennerholm; Anna-Karina Aaris Henningsen; LB Romundstad; C Bergh; A Pinborg; R Skjaerven; J Forman; M Gissler; KG Nygren; A Tiitinen

doi:10.1093/humrep/det272

Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study from the CoNARTaS group

UB Wennerholm, Anna-Karina Aaris Henningsen, LB Romundstad, C Bergh, A Pinborg, R Skjaerven, J Forman, M Gissler, KG Nygren, A Tiitinen

221 Citations (Scopus)

Abstract

STUDY QUESTIONSWhat are the risks of adverse outcomes in singletons born after frozen-thawed embryo transfer (FET)?SUMMARY ANSWERSingletons born after FET have a better perinatal outcome compared with singletons born after fresh IVF and ICSI as regards low birthweight (LBW) and preterm birth (PTB), but a worse perinatal outcome compared with singletons born after spontaneous conception.WHAT IS KNOWN ALREADYPrevious studies have shown a worse perinatal outcome in children born after IVF in general compared with children born after spontaneous conception. In singletons born after FET, a lower rate of PTB and LBW and a higher rate of large for gestational age (LGA) compared with singletons born after fresh IVF have been shown.STUDY DESIGNA retrospective Nordic population-based cohort study of all singletons conceived after FET in Denmark, Norway and Sweden until December 2007 was performed.PARTICIPANTS/ MATERIALS, SETTING AND METHODSSingletons born after FET (n = 6647) were compared with a control group of singletons born after fresh IVF and ICSI (n = 42 242) and singletons born after spontaneous conception (n = 288 542). Data on perinatal outcomes were obtained by linkage to the national Medical Birth Registries. Odds ratios were calculated for several perinatal outcomes and adjustments were made for maternal age, parity, year of birth, offspring sex and country of origin.MAIN RESULTS AND THE ROLE OF CHANCESingletons born after FET had a lower risk of LBW (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.71-0.91), PTB (aOR 0.84, 95% CI 0.76-0.92), very PTB (VPTB; aOR 0.79, 95% CI 0.66-0.95) and small for gestational age (SGA; aOR 0.72, 95% CI 0.62-0.83), but a higher risk of post-term birth (aOR 1.40, 95% CI 1.27-1.55), LGA (aOR 1.45, 95% CI 1.27-1.64), macrosomia (aOR 1.58, 95% CI 1.39-1.80) and perinatal mortality (aOR 1.49, 95% CI 1.07-2.07) compared with singletons born after fresh IVF and ICSI. Compared with children conceived after spontaneous conception, singletons born after FET had a higher risk of LBW (aOR 1.27, 95% CI 1.13-1.43), very LBW (aOR 1.69, 95% CI 1.33-2.15), PTB (aOR 1.49, 95% CI 1.35-1.63), VPTB (aOR 2.68, 95% CI 2.24-3.22), SGA (aOR 1.18, 95% CI 1.03-1.35), LGA (aOR 1.29, 95% CI 1.15-1.45), macrosomia (aOR 1.29, 95% CI 1.15-1.45) and perinatal (aOR 1.39, 95% CI 1.03-1.87) neonatal (aOR 1.87, 95% CI 1.23-2.84) and infant mortality (aOR 1.92, 95% CI 1.36-2.72). When analyzing trends over time, the risk of being born LGA increased over time for singletons born after FET compared with singletons born after fresh IVF and ICSI (P = 0.04).LIMITATIONS, REASONS FOR CAUTIONAs in all observational studies, the possible role of residual confounding factors and bias should be considered. In this study, we were not able to control for confounding factors, such as BMI, smoking and reason for, or length of, infertility.WIDER IMPLICATIONS OF THE FINDINGSPerinatal outcomes in this large population-based cohort of children born after FET from three Nordic countries compared with fresh IVF and ICSI and spontaneous conception were in agreement with the literature.

Original language	Undefined/Unknown
Journal	Human Reproduction
Volume	28
Issue number	9
Pages (from-to)	2545-2553
Number of pages	9
ISSN	0268-1161
DOIs	https://doi.org/10.1093/humrep/det272
Publication status	Published - Sept 2013

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1093/humrep/det272

Cite this

@article{5a08e0cb6a9c4dd3bd8f63ed61365b05,

title = "Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study from the CoNARTaS group",

abstract = "STUDY QUESTIONSWhat are the risks of adverse outcomes in singletons born after frozen-thawed embryo transfer (FET)?SUMMARY ANSWERSingletons born after FET have a better perinatal outcome compared with singletons born after fresh IVF and ICSI as regards low birthweight (LBW) and preterm birth (PTB), but a worse perinatal outcome compared with singletons born after spontaneous conception.WHAT IS KNOWN ALREADYPrevious studies have shown a worse perinatal outcome in children born after IVF in general compared with children born after spontaneous conception. In singletons born after FET, a lower rate of PTB and LBW and a higher rate of large for gestational age (LGA) compared with singletons born after fresh IVF have been shown.STUDY DESIGNA retrospective Nordic population-based cohort study of all singletons conceived after FET in Denmark, Norway and Sweden until December 2007 was performed.PARTICIPANTS/ MATERIALS, SETTING AND METHODSSingletons born after FET (n = 6647) were compared with a control group of singletons born after fresh IVF and ICSI (n = 42 242) and singletons born after spontaneous conception (n = 288 542). Data on perinatal outcomes were obtained by linkage to the national Medical Birth Registries. Odds ratios were calculated for several perinatal outcomes and adjustments were made for maternal age, parity, year of birth, offspring sex and country of origin.MAIN RESULTS AND THE ROLE OF CHANCESingletons born after FET had a lower risk of LBW (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.71-0.91), PTB (aOR 0.84, 95% CI 0.76-0.92), very PTB (VPTB; aOR 0.79, 95% CI 0.66-0.95) and small for gestational age (SGA; aOR 0.72, 95% CI 0.62-0.83), but a higher risk of post-term birth (aOR 1.40, 95% CI 1.27-1.55), LGA (aOR 1.45, 95% CI 1.27-1.64), macrosomia (aOR 1.58, 95% CI 1.39-1.80) and perinatal mortality (aOR 1.49, 95% CI 1.07-2.07) compared with singletons born after fresh IVF and ICSI. Compared with children conceived after spontaneous conception, singletons born after FET had a higher risk of LBW (aOR 1.27, 95% CI 1.13-1.43), very LBW (aOR 1.69, 95% CI 1.33-2.15), PTB (aOR 1.49, 95% CI 1.35-1.63), VPTB (aOR 2.68, 95% CI 2.24-3.22), SGA (aOR 1.18, 95% CI 1.03-1.35), LGA (aOR 1.29, 95% CI 1.15-1.45), macrosomia (aOR 1.29, 95% CI 1.15-1.45) and perinatal (aOR 1.39, 95% CI 1.03-1.87) neonatal (aOR 1.87, 95% CI 1.23-2.84) and infant mortality (aOR 1.92, 95% CI 1.36-2.72). When analyzing trends over time, the risk of being born LGA increased over time for singletons born after FET compared with singletons born after fresh IVF and ICSI (P = 0.04).LIMITATIONS, REASONS FOR CAUTIONAs in all observational studies, the possible role of residual confounding factors and bias should be considered. In this study, we were not able to control for confounding factors, such as BMI, smoking and reason for, or length of, infertility.WIDER IMPLICATIONS OF THE FINDINGSPerinatal outcomes in this large population-based cohort of children born after FET from three Nordic countries compared with fresh IVF and ICSI and spontaneous conception were in agreement with the literature.",

author = "UB Wennerholm and Henningsen, {Anna-Karina Aaris} and LB Romundstad and C Bergh and A Pinborg and R Skjaerven and J Forman and M Gissler and KG Nygren and A Tiitinen",

year = "2013",

month = sep,

doi = "10.1093/humrep/det272",

language = "Udefineret/Ukendt",

volume = "28",

pages = "2545--2553",

journal = "Human Reproduction",

issn = "0268-1161",

publisher = "Oxford Academic",

number = "9",

}

TY - JOUR

T1 - Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study from the CoNARTaS group

AU - Wennerholm, UB

AU - Henningsen, Anna-Karina Aaris

AU - Romundstad, LB

AU - Bergh, C

AU - Pinborg, A

AU - Skjaerven, R

AU - Forman, J

AU - Gissler, M

AU - Nygren, KG

AU - Tiitinen, A

PY - 2013/9

Y1 - 2013/9

N2 - STUDY QUESTIONSWhat are the risks of adverse outcomes in singletons born after frozen-thawed embryo transfer (FET)?SUMMARY ANSWERSingletons born after FET have a better perinatal outcome compared with singletons born after fresh IVF and ICSI as regards low birthweight (LBW) and preterm birth (PTB), but a worse perinatal outcome compared with singletons born after spontaneous conception.WHAT IS KNOWN ALREADYPrevious studies have shown a worse perinatal outcome in children born after IVF in general compared with children born after spontaneous conception. In singletons born after FET, a lower rate of PTB and LBW and a higher rate of large for gestational age (LGA) compared with singletons born after fresh IVF have been shown.STUDY DESIGNA retrospective Nordic population-based cohort study of all singletons conceived after FET in Denmark, Norway and Sweden until December 2007 was performed.PARTICIPANTS/ MATERIALS, SETTING AND METHODSSingletons born after FET (n = 6647) were compared with a control group of singletons born after fresh IVF and ICSI (n = 42 242) and singletons born after spontaneous conception (n = 288 542). Data on perinatal outcomes were obtained by linkage to the national Medical Birth Registries. Odds ratios were calculated for several perinatal outcomes and adjustments were made for maternal age, parity, year of birth, offspring sex and country of origin.MAIN RESULTS AND THE ROLE OF CHANCESingletons born after FET had a lower risk of LBW (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.71-0.91), PTB (aOR 0.84, 95% CI 0.76-0.92), very PTB (VPTB; aOR 0.79, 95% CI 0.66-0.95) and small for gestational age (SGA; aOR 0.72, 95% CI 0.62-0.83), but a higher risk of post-term birth (aOR 1.40, 95% CI 1.27-1.55), LGA (aOR 1.45, 95% CI 1.27-1.64), macrosomia (aOR 1.58, 95% CI 1.39-1.80) and perinatal mortality (aOR 1.49, 95% CI 1.07-2.07) compared with singletons born after fresh IVF and ICSI. Compared with children conceived after spontaneous conception, singletons born after FET had a higher risk of LBW (aOR 1.27, 95% CI 1.13-1.43), very LBW (aOR 1.69, 95% CI 1.33-2.15), PTB (aOR 1.49, 95% CI 1.35-1.63), VPTB (aOR 2.68, 95% CI 2.24-3.22), SGA (aOR 1.18, 95% CI 1.03-1.35), LGA (aOR 1.29, 95% CI 1.15-1.45), macrosomia (aOR 1.29, 95% CI 1.15-1.45) and perinatal (aOR 1.39, 95% CI 1.03-1.87) neonatal (aOR 1.87, 95% CI 1.23-2.84) and infant mortality (aOR 1.92, 95% CI 1.36-2.72). When analyzing trends over time, the risk of being born LGA increased over time for singletons born after FET compared with singletons born after fresh IVF and ICSI (P = 0.04).LIMITATIONS, REASONS FOR CAUTIONAs in all observational studies, the possible role of residual confounding factors and bias should be considered. In this study, we were not able to control for confounding factors, such as BMI, smoking and reason for, or length of, infertility.WIDER IMPLICATIONS OF THE FINDINGSPerinatal outcomes in this large population-based cohort of children born after FET from three Nordic countries compared with fresh IVF and ICSI and spontaneous conception were in agreement with the literature.

AB - STUDY QUESTIONSWhat are the risks of adverse outcomes in singletons born after frozen-thawed embryo transfer (FET)?SUMMARY ANSWERSingletons born after FET have a better perinatal outcome compared with singletons born after fresh IVF and ICSI as regards low birthweight (LBW) and preterm birth (PTB), but a worse perinatal outcome compared with singletons born after spontaneous conception.WHAT IS KNOWN ALREADYPrevious studies have shown a worse perinatal outcome in children born after IVF in general compared with children born after spontaneous conception. In singletons born after FET, a lower rate of PTB and LBW and a higher rate of large for gestational age (LGA) compared with singletons born after fresh IVF have been shown.STUDY DESIGNA retrospective Nordic population-based cohort study of all singletons conceived after FET in Denmark, Norway and Sweden until December 2007 was performed.PARTICIPANTS/ MATERIALS, SETTING AND METHODSSingletons born after FET (n = 6647) were compared with a control group of singletons born after fresh IVF and ICSI (n = 42 242) and singletons born after spontaneous conception (n = 288 542). Data on perinatal outcomes were obtained by linkage to the national Medical Birth Registries. Odds ratios were calculated for several perinatal outcomes and adjustments were made for maternal age, parity, year of birth, offspring sex and country of origin.MAIN RESULTS AND THE ROLE OF CHANCESingletons born after FET had a lower risk of LBW (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.71-0.91), PTB (aOR 0.84, 95% CI 0.76-0.92), very PTB (VPTB; aOR 0.79, 95% CI 0.66-0.95) and small for gestational age (SGA; aOR 0.72, 95% CI 0.62-0.83), but a higher risk of post-term birth (aOR 1.40, 95% CI 1.27-1.55), LGA (aOR 1.45, 95% CI 1.27-1.64), macrosomia (aOR 1.58, 95% CI 1.39-1.80) and perinatal mortality (aOR 1.49, 95% CI 1.07-2.07) compared with singletons born after fresh IVF and ICSI. Compared with children conceived after spontaneous conception, singletons born after FET had a higher risk of LBW (aOR 1.27, 95% CI 1.13-1.43), very LBW (aOR 1.69, 95% CI 1.33-2.15), PTB (aOR 1.49, 95% CI 1.35-1.63), VPTB (aOR 2.68, 95% CI 2.24-3.22), SGA (aOR 1.18, 95% CI 1.03-1.35), LGA (aOR 1.29, 95% CI 1.15-1.45), macrosomia (aOR 1.29, 95% CI 1.15-1.45) and perinatal (aOR 1.39, 95% CI 1.03-1.87) neonatal (aOR 1.87, 95% CI 1.23-2.84) and infant mortality (aOR 1.92, 95% CI 1.36-2.72). When analyzing trends over time, the risk of being born LGA increased over time for singletons born after FET compared with singletons born after fresh IVF and ICSI (P = 0.04).LIMITATIONS, REASONS FOR CAUTIONAs in all observational studies, the possible role of residual confounding factors and bias should be considered. In this study, we were not able to control for confounding factors, such as BMI, smoking and reason for, or length of, infertility.WIDER IMPLICATIONS OF THE FINDINGSPerinatal outcomes in this large population-based cohort of children born after FET from three Nordic countries compared with fresh IVF and ICSI and spontaneous conception were in agreement with the literature.

U2 - 10.1093/humrep/det272

DO - 10.1093/humrep/det272

M3 - Tidsskriftartikel

SN - 0268-1161

VL - 28

SP - 2545

EP - 2553

JO - Human Reproduction

JF - Human Reproduction

IS - 9

ER -