Quality of IVF status registration in the Estonian Medical Birth Registry: a national record linkage study

Kärt Allvee,Kaja Rahu,Mati Rahu,Helle Karro,Kai Haldre

doi:10.1186/s12978-018-0575-7

Abstract

BackgroundInformation regarding in vitro fertilization (IVF) as a pregnancy risk factor (yes/ no) is stored in each birth record of the Estonian Medical Birth Registry (EMBR). This study aimed to assess the validity of registration of newborns’ IVF status in the EMBR.MethodsTo identify the newborns conceived by IVF, the birth records in the EMBR were compared to individual records on the embryo transfer procedures in the Estonian Health Insurance Fund (EHIF) database as a reference. Maternal age was restricted to 40 years, the age limit for IVF treatment covered by the EHIF. The embryo transfer procedures, that dated up to eight weeks before pregnancy, were additionally checked in the infertility treatment clinics. The validity of IVF status was measured by sensitivity, specificity, positive and negative predictive values (PPV and NPV). Relative risk (RR) of unrecorded IVF status among IVF mothers by socio-demographic characteristics and birth plurality was estimated using modified Poisson regression models.ResultsThere were 3198 newborns identified as conceived by IVF in the EMBR in 2005–2014. Eight of them were incorrectly entered as born after IVF. The record linkage with the EHIF database revealed 1014 newborns with unrecorded IVF status in the EMBR. A total of 4204 newborns were verified as conceived by IVF, 24.1% of them were not categorized as born after IVF. The sensitivity of the IVF status registration was poor (75.9%), specificity (100.0%), PPV (99.8%) and NPV (99.3%) were high. The misclassifications were significantly more common among mothers of younger age or non-Estonians or with singleton birth.ConclusionInformation based on mother’s self-report or her antenatal chart does not accurately identify the newborn’s IVF status. The lack of a specialized country-wide assisted reproductive technology register in Estonia requires routine record linkage of the EMBR, EHIF and the infertility treatment clinics’ databases to obtain adequate information regarding IVF status in the EMBR. Electronic record linkages between databases would help considerably to improve the validity of data to be used in medical decision making, in research and for statistical purposes.

Highlights

Information regarding in vitro fertilization (IVF) as a pregnancy risk factor is stored in each birth record of the Estonian Medical Birth Registry (EMBR)
The record linkage with the Estonian Health Insurance Fund (EHIF) database resulted in 3912 newborns in the EMBR with the corresponding embryo transfer record, whereas 1002 of them were with unrecorded IVF status, i.e., erroneously categorized as conceived spontaneously (Fig. 1)
From the 151 additional comparisons of birth records with the embryo transfer procedure before the beginning of pregnancy in the infertility treatment clinics, 14 newborns were verified as born after IVF and 12 newborns notified with non-IVF status were found to be conceived by IVF (Fig. 1)

Summary

Introduction

Information regarding in vitro fertilization (IVF) as a pregnancy risk factor (yes/ no) is stored in each birth record of the Estonian Medical Birth Registry (EMBR). The 2014 Estonian Women’s Health Questionnaire Survey indicated that 15.8% of the sexually active respondents at 18–44 years of age had experienced infertility, and 13.4% of them reported the use of in vitro fertilization (IVF) to have a child [1]. As there is currently no specialized country-wide assisted reproductive technology register in Estonia, sole information regarding IVF as a pregnancy risk factor (yes/ no) (defined as embryo transfer after conventional in vitro insemination or intracytoplasmic sperm injection [3]) is stored in each birth record of the Estonian Medical Birth Registry (EMBR). The IVF status is recorded on the birth notification form by the mothers’ self-report or using her antenatal chart. Majority of the IVF procedures are recorded in the reimbursement database with women’s PINs [5]

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