Research

IVF and VACTERL: higher adjusted odds, a 1.3-per-10,000 absolute excess

NICU360 Evidence Desk·6 min read·00

Across 1.56 million live births, VACTERL was recorded in 2.3 per 10,000 IVF births and 1.2 per 10,000 naturally conceived births. Adjusted odds were higher, but the absolute excess was about 1.3 per 10,000—and this observational study cannot establish causation.

THE HOT TAKE

The adjusted association deserves follow-up. The 1.3-per-10,000 absolute excess is the number that keeps the result in proportion.
— NICU360 Evidence Desk

A population-based cohort linked IVF cycle records, birth certificates, and birth-defect registries for 1,555,936 live births in Massachusetts, New York, North Carolina, and Texas from 2004 through 2018; Texas data ended in 2017. It included 175,161 IVF-conceived births and a 10:1 comparison sample of 1,380,775 naturally conceived births.

VACTERL prevalence per 10,000 live births

Natural conception

IVF conception

Cases per 10,000 live births

The primary VACTERL counts

Conception group	VACTERL cases	Live births	Rate per 10,000 (95% CI)
Naturally conceived	159	1,380,775	1.2 (1.0–1.4)

Was this worth carrying into your next shift?

Your reaction stays connected to your NICU360 profile.

Comments

Join the conversation

Loading conversation…

Study feature	Why it matters
Large linked population cohort	A denominator of more than 1.5 million live births makes a rare outcome measurable, although only 200 cases occurred.
Standardized case definition	VACTERL required at least three specified component phenotypes, with chromosomal and known syndromic cases excluded.
Sensitivity analyses	Singleton-only, one-child-per-mother, and maternal-BMI analyses were broadly consistent.
Only 41 IVF-exposed cases	The estimate remains vulnerable to sparse-event instability and its confidence interval is wide.
Live births only	Miscarriages, stillbirths, and pregnancy terminations were absent, leaving selection bias unresolved.
Residual confounding	The data could not fully address subfertility, donor characteristics, surrogacy, or other unmeasured differences.
Historical and heterogeneous surveillance	Births occurred in 2004–2018, and defect ascertainment was primarily passive in New York but active in the other states.

IVF and VACTERL: higher adjusted odds, a 1.3-per-10,000 absolute excess

THE HOT TAKE

Comments

WHAT THE COHORT ACTUALLY COMPARED

Identify IVF exposure

Build the comparison sample

Apply the VACTERL definition

Adjust measured differences

WHY THE DENOMINATOR CHANGES THE STORY

WHAT SHOULD TEMPER THE RESULT

PRACTICAL INTERPRETATION