Early Pregnancy Cohort and Preimplantation Factor

The investigators aim to evaluate Preimplantation Factor (PIF) throughout the first trimester we need to employ two settings of recruitment.

Early part:

The PEP in ART (PEP-A) will enroll participants referred for fertility treatment at Rigshospitalet and North Zealand Hospital. Participants all have cryopreserved embryos suitable for frozen embryo transfer in a natural menstrual cycle. No type of ovulation trigger will be employed, as the LH peak is monitored via home urine-LH test.

For a thorough examination of the luteal phase, participants are recalled for blood samples on day 7, 11, 14 and 16 after positive urine-LH test. Hereafter positive serum human chorionic gonadotropin (hCG) denotes a pregnancy and these participants are offered to continue in the later part of the PEP-cohort.

Late part:

PEP in Spontaneous conceptions (PEP-S) represents the sampling of expected normal pregnancies from the local community. Enrolled at the time of the first positive pregnancy test, participants are expected to be included from approximately 5 weeks of gestation. Hereafter participants are recalled every two weeks for blood sampling and transvaginal ultrasonographys of endometrial thickness until a gestational sac and yolk sac are visible for mean sac diameter measuring and eventually the crown-rump-length.

Research biobank All collected data: questionnaires of medical history before enrollment, ultrasonographys and blood samples of progesterone, 17-OH-progesterone, estradiol, alpha-feto-protein (AFP), pregnancy associated placental protein A (PAPP-A), hCG and PIF are stored in a research biobank.

PEP-A

Inclusion criteria

• Women in ART treatment by natural cycle frozen embryo transfer only monitored by urine LH.
• Age above 18 years.
• Ability to understand read and write Danish for the informed consent.
• Planned delivery at the hospitals involved in the project.

Exclusion criteria

• Abnormal uterine anatomy or function already known or estimated at first transvaginal ultrasonography.
• History of recurrent pregnancy loss.
• Ongoing or former (at least 12 months of no use) narcotics or alcohol abuse (above 14 units of alcohol per week).
• Contraindication for pregnancy.

PEP-S

Inclusion criteria

• Spontaneous pregnancy in women above 18 years of age.
• Gestational age of singleton pregnancy below full eight weeks by first transvaginal ultrasound.
• Ability to understand read and write Danish for the informed consent.
• Planned delivery at the hospitals involved in the project.

Exclusion criteria

• All types of ART treatment in the actual pregnancy.
• Abnormal uterine anatomy or function already known or estimated at first transvaginal ultrasonography.
• History of recurrent pregnancy loss.
• Ongoing or former (at least 12 months of no use) narcotics or alcohol abuse (above 14 units of alcohol per week).
• Contraindication for pregnancy.