The choice for invasive prenatal tests after subfertility

Figures & data

Figure 1. Flowchart of patients in the study cohort.

Table 1. Population characteristics of the primary study group (women with a documented history of fertility treatment or investigation) and the control group (women with a spontaneous pregnancy and no known history of subfertility).

	Primary study group (n = 977)	Control group (n = 8122)	p Value
Maternal age (year)	31.4	31.9	0.065
Maternal weight (kg)	71.8	74.3	0.006*
BMI	25.4	26.2	0.014*
Smokers (%)	9.4%	15.9%	0.002*
Conception (%)
Spontaneous	17%
Ovulation induction	20%
Homologous insemination	13%
Heterologous insemination	2%
IVF	14%
ICSI	33%
Oocyte donation	0.01%

Data are expressed as mean or percentage (%).

* p < 0.05, that is considered to be significant.

Table 2. Uptake of invasive prenatal test (IPT) for different indication (abnormal cFTS, abnormal STS and AMA) expressed in odds ratio’s (OR) and 95% CI and adjusted odds ratio’s (AdjOR) for different confounders per indication.

	Primary study group (n = 977)	Control group (n = 8122)	OR (95% CI)	AdjOR (95% CI)
Women in the primary group opting for IPT (out of the total number with indication abnormal cFTS)	55.6% (10/18)	75.8% (91/120)	0.40 (0.141.10)	0.52 (0.18–1.56)^a
Women in the secondary group opting for IPT (out of the total number with indication abnormal cFTS)	54.5% (6/11)	75.8% (91/120)	0.38 (0.11–1.35)	0.56 (0.14–2.23)^a
Women in the primary group opting for IPT (out of the total number with indication abnormal STS)	12.6% (17/135)	20% (300/1501)	0.58 (0.34–0.97)*	0.59 (0.32–1.08)^b
Women in the secondary group opting for IPT (out of the total number with indication abnormal STS)	11.5% (14/122)	20% (300/1501)	0.52 (0.29–0.92)*	0.52 (0.27–1.00)^b
Women in the primary group opting for IPT (out of the total number with indication abnormal AMA)	15.8% (34/215)	19.3% (348/1799)	0.78 (0.53–1.15)	0.91 (0.62–1.35)^c
Women in the secondary group opting for IPT (out of the total number with indication abnormal AMA)	15.0% (27/180)	19.3% (348/1799)	0.74 (0.48–1.13)	0.86 (0.56–1.33)^c

Primary study group (women with a documented history of fertility treatment or investigation) versus the control group (women with a spontaneous pregnancy and no known history of subfertility).

^aCorrected for risk T21 and maternal age.

^bCorrected for maternal age and severity anomaly.

^cCorrected for maternal age.

*p < 0.05, that is considered to be significant.

Table 3. Bivariate logistic regression analyses of factors possibly influencing the choice for IPT in the secondary study group.

	OR	95% CI	p Value
Maternal age	1.14	1.08–1.20	<0.001*
Duration of treatment	1.00	0.99–1.01	0.956
Duration of subfertility	1.01	1.00–1.03	0.059
Fertility treatment	0.91	0.48–1.77	0.869
Primary/secondary subfertility	1.60	0.88–2.90	0.150

Chi-square tests were used to calculate odd’s ratios of the effect.

*p < 0.05, that is considered to be significant.