Heterotopic pregnancy (HP) is the simultaneous occurrence of intrauterine and ectopic pregnancies (EP). The incidence of HPs occurring spontaneously ranges from 1 in 10,000 to 1 in 30,000. However, this incidence is reported to be 1 in 100 pregnancies following artificial reproductive techniques. HP is a potentially life-threatening condition that is frequently misdiagnosed, as most diagnoses for HPs are delayed, and are only made after rupture of the EP. A high index of suspicion is, therefore, required for an accurate and timely diagnosis in order to reduce maternal morbidity and mortality, which currently stands at 1 in 200,000 live births. The most common risk factors include pelvic inflammatory disease, previous EP, assisted reproduction techniques, and ovarian hyperstimulation syndrome.
Transvaginal ultrasound is the gold standard for diagnosis. As detection of an intrauterine pregnancy often leads to the mistaken exclusion of a concomitant EP, a careful transvaginal scanning of the uterus and appendages should be performed in all females of reproductive age with a positive pregnancy test and red flags in anamnesis, and/or with clinical symptoms. Routine transvaginal ultrasound at Day 27 after embryo transfer could facilitate the diagnosis of HP; however, symptoms onset before or after Day 27 are clues to early diagnosis. MRI can be very helpful in diagnosing atypical cases.
Trisomy 21 in both fetuses in a DCDA twin pregnancy
