When to tell people you’re pregnant?

I’d like to share some data that can aid in your decision.

(1) Understand what your miscarriage risk profile looks like

Miscarriage rates increase with maternal (and paternal) age and are also different for IVF than natural conception. Read this comprehensive article on miscarriage rates for more info.

For couples who have conceived naturally, miscarriage rates drop dramatically after 8 weeks.

Screen Shot 2016-06-05 at 2.55.06 PM

Source: Analysis based on Wilcox AJ, Baird DD, Weinberg CR (1999). “Time of implantation of the conceptus and loss of pregnancy.” and Wang X, Chen C, Wang L, Chen D, Guang W, French J (2003). “Conception, early pregnancy loss, and time to clinical pregnancy: a population-based prospective study.”

For IVF/ISCI candidates, miscarriage rates drop significantly in first 7 weeks and plateau after about 11 weeks.

Figure 1. Risk of spontaneous abortion per fetal sac in relation to gestational age (comparison of twin pregnancies versus singleton pregnancies). +FHR = positive fetal heart rate.

miscarriage rates IVF.gif

Source: Risk of spontaneous abortion in singleton and twin pregnancies after IVF/ICSI. Authors: Philippe TummersPaul De Sutter and Marc Dhont. 

(2) Wait for a Fetal Heartbeat

Risk of miscarriage goes down significantly when a fetal heartbeat is found during an ultrasound around 6-8 weeks. Higher heart rates seem to predict better outcomes. Ask your OB/GYN to tell you the heart rate of the fetus.

Up to 6 weeks 2 days gestation:

screen-shot-2015-07-27-at-1-46-32-pmSource: Data from Doubilet & Benson (1994) Embryonic Heart Rate in the First Trimester: What Is Normal? Journal of Ultrasound Medicine.

Between 6 weeks 3 days and 7 weeks 0 days:

screen-shot-2015-07-27-at-2-58-29-pmSource: Data from Doubilet & Benson (1994) Embryonic Heart Rate in the First Trimester: What Is Normal? Journal of Ultrasound Medicine.

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