Cohort profile: InTraUterine sampling in early pregnancy (ITU), a prospective pregnancy cohort study in Finland: study design and baseline characteristics

PURPOSE

The InTraUterine sampling in early pregnancy (ITU) is a prospective pregnancy cohort study. The overarching aim of ITU is to unravel genomic, epigenomic, transcriptomic, endocrine, inflammatory and metabolic maternal-placental-fetal mechanisms involved in the programming of health and disease after exposure to prenatal environmental adversity, such as maternal malnutrition, cardiometabolic disorders, infections, medical interventions, mental disorders and psychosocial stress. This paper describes the study protocol, design and baseline characteristics of the cohort.

PARTICIPANTS

We included 944 pregnant Finnish women, their partners and children born alive between April 2012 and December 2017. The women were recruited through the national, voluntary trisomy 21 screening between 9⁺⁰ and 21⁺⁶ gestational weeks. Of the participating women, 543 were screen positive and underwent fetal chromosomal testing. Test result of these women suggested no fetal chromosomal abnormality. Further, we recruited 401 women who were screen negative and who did not undergo fetal chromosomal testing.

FINDINGS TO DATE

We have collected chorionic villi and amniotic fluid from the screen-positive women; blood, urine, buccal swabs and diurnal salivary samples from all women; blood and buccal swabs from all partners; and placenta, cord blood and buccal swabs from all newborns for analyses of the genome, epigenome, transcriptome, and endocrine, inflammatory and metabolic markers. These data are coupled with comprehensive phenotypes, including questions on demographic characteristics, health and well-being of the women and their partners during pregnancy and of the women and their children at the child's age of 1.7 and 3 years. Data also come from patient records and nationwide registers covering health, lifestyle and medication data.

FUTURE PLANS

Multiple layers of ITU data allow integrative data analyses, which translate to biomarker identification and allow risk stratification and understanding of the biological mechanisms involved in prenatal programming of health and disease.

Characteristics of epigenetic aging across gestational and perinatal tissues

Background

Epigenetic clocks have been used to indicate differences in biological states between individuals of same chronological age. However, so far, only few studies have examined epigenetic aging in newborns—especially regarding different gestational or perinatal tissues. In this study, we investigated which birth- and pregnancy-related variables are most important in predicting gestational epigenetic age acceleration or deceleration (i.e., the deviation between gestational epigenetic age estimated from the DNA methylome and chronological gestational age) in chorionic villus, placenta and cord blood tissues from two independent study cohorts (ITU, n = 639 and PREDO, n = 966). We further characterized the correspondence of epigenetic age deviations between these tissues.

Results

Among the most predictive factors of epigenetic age deviations in single tissues were child sex, birth length, maternal smoking during pregnancy, maternal mental disorders until childbirth, delivery mode and parity. However, the specific factors related to epigenetic age deviation and the direction of association differed across tissues. In individuals with samples available from more than one tissue, relative epigenetic age deviations were not correlated across tissues.

Conclusion

Gestational epigenetic age acceleration or deceleration was not related to more favorable or unfavorable factors in one direction in the investigated tissues, and the relative epigenetic age differed between tissues of the same person. This indicates that epigenetic age deviations associate with distinct, tissue specific, factors during the gestational and perinatal period. Our findings suggest that the epigenetic age of the newborn should be seen as a characteristic of a specific tissue, and less as a general characteristic of the child itself.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01080-y.

Angiogenic profile and smoking in the Finnish Genetics of Pre-Eclampsia Consortium (FINNPEC) cohort

OBJECTIVES

The biological mechanism by which smoking reduces the risk of pre-eclampsia (PE) is unresolved. We studied serum levels of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF) and their ratio, in addition to soluble endoglin (sEng) in early and late pregnancy to ascertain whether these factors are altered in women who smoke.

SUBJECTS AND METHODS

First trimester serum samples were available from 217 women who later developed PE and 238 women who did not develop PE. Second/third trimester serum samples were available from 174 PE and 54 non-PE women.

RESULTS

PE women who smoked during pregnancy had elevated first trimester concentrations of serum PlGF [geometric mean (95% CI): 39.8 (32.6-48.5) pg/ml, p = .001] and reduced sEng concentration [5.0 (4.6-5.6) ng/ml, p = .047] compared to PE non-smokers [30.0 (28.1-32.1) pg/ml and 6.1 (5.9-6.4) ng/ml, respectively]. Non-smoking women in the PE group had the highest sFlt-1/PlGF ratio in early and late pregnancy.

CONCLUSIONS

The protective effect of smoking in reducing the risk of PE may be due to the early pregnancy change towards pro-angiogenic marker profile. Also, in late pregnancy, smoking exerted effect in sFlt-1/PlGF ratio in PE pregnancies, and may complicate its use as a prognostic and diagnostic marker. Key messages Smoking appears to have angiogenic effects in early pregnancy with reduced sEng concentrations and elevated PlGF concentrations in both normal and PE pregnancies. Throughout pregnancy, smoking exerted effect in PlGF concentration and sFlt-1/PlGF ratio in PE pregnancies, and thus may complicate its use as a prognostic and diagnostic marker.

Natural history of familial myomas

OBJECTIVE

To study the natural history of myomas in familial cases and to compare the tendencies of myomas between familial and non-familial cases.

STUDY DESIGN

Subjects with familial and non-familial myomas were identified from the hospital records and the reliable details of the myomas were collected.

RESULTS

In the familial cases there are several myomas, four or more. In the non-familial cases, there is usually only one single myoma, which is bigger than in familial cases. In the familial group, the diagnosis and surgery was made earlier. In the familial group, there were more pregnancies and less infertility problems.

CONCLUSION

There is a significant difference in the natural history of the familial and non-familial cases. In familial cases, subjects have four or more myomas while in non-familial cases the fibroid is single and large.

Effect of the prostaglandin E1 analogue gemeprost on the blood flow velocity waveforms of uterine arteries during the first trimester of pregnancy

OBJECTIVE

To investigate the effect of the vaginal application of the prostaglandin (PGE1) analogue gemeprost on the vascular resistance of the main uterine arteries in early pregnancy.

DESIGN

A prospective observational study.

SUBJECTS

Twenty-one patients seeking legal termination of pregnancy at 7-12 weeks gestation.

METHODS

Pulsatility indices for the main uterine arteries were measured by vaginal colour Doppler ultrasound before and 3 to 4 h after vaginal application of the PGE1 analogue gemeprost.

RESULTS

A significant increase of pulsatility indices was observed (P < 0.001) which was not affected by parity or gestational age. The change was similar in both uterine arteries, and placental lateralisation did not affect the results. All fetuses were still alive at the second examination.

CONCLUSIONS

Vaginal application of prostaglandin analogue gemeprost in early pregnancy increases the vascular resistance of uterine arteries. This may be caused by a direct vasoconstrictory effect or be secondary to uterine contractions.

Femorotibial bypass grafting for lower limb ischaemia

The results of 305 femorotibial bypass grafts performed in 246 patients are presented. Of these operations 246 were primary and 58 secondary or tertiary. A total of 66 diabetic patients were in the series. An autogenous saphenous vein graft was employed in 196 primary operations, the other grafts used being PTFE, human umbilical cord vein graft, venous allograft and knitted dacron velour graft. Hospital mortality was 8 patients (2.6%), while late mortality was 73 patients, 39 of them having had patent grafts. There were 89 (29.2%) immediate or early hospital failures. Two-hundred-sixteen grafts were followed for a mean observation time of 62.3 +/- 5.7 months. The cumulative patencies were analyzed using the life-table method. One, five, and ten year overall patencies for saphenous vein grafts as indicated by claudication were 73%, 53% and 35%, respectively. In rest pain, the patency rates were 62%, 46% and 40% at similar intervals. In impending gangrene the patencies were 43%, 35% and 20%, respectively. The patencies for arterial substitutes were generally poor, i.e., 35% and 15% at one and five years. None of the graft substitutes were followed for up to ten years. Diabetic patients had a significantly lower patency rate than nondiabetics (p = 0.002). The impact was remarkable if impending gangrene co-existed. In all these situations the early graft failure ensued. Both the run-off and inflow status affected the patency rates. This was significantly lower (p = 0.001) when only one distal branch was visualized in angiography.