Fertility of woman and man General

Planning fertility treatment: When to think about another child?

After a long wait, you hold your little bundle of joy, your baby, finally in your arms. A beautiful, exciting, happy moment.

Nevertheless, after the first months of getting used to each other and getting used to the new life situation, it is not uncommon to direct your thoughts to the future as well and to wonder about a sibling for your toddler. Another child, for many, is still part of the picture of the “ideal” family: children who play with a sibling, who sometimes argue, but above all benefit. But when, many wonder, is the ideal time for a sibling to join the family?

Many opinion leaders believe that the best age gap between siblings is around three years.

In Germany, statistically, the second child comes 3.3 years after the first one. But how suitable is such an age gap between siblings when they have been conceived with medical asstistance?

Fertility treatment: time between pregnancies influences success rate.

Both a too short and a too long time interval between childbirth and the beginning of a new fertility treatment can significantly reduce the likelihood of pregnancy and live birth, according to a retrospective study. These are the findings of a study by a group of researchers from the University of California. The scientists compared the treatment outcomes of women who had started fertility treatment within six months of childbirth to those of women who did not start therapy until after more than 24 months. The study evaluated more than 61,600 treatment cycles from 2004-2013. It became clear that a time interval between delivery and subsequent treatment of less than six months was associated with a 5.6% reduction in the likelihood of clinical pregnancy (p = 0.009%). The probability of a live birth was also reduced by 6.8%. On the contrary, if the beginning of a fertility treatment was within a period of 12-18 months after the last delivery, the chances were much better. On the other hand, if the women waited more than 24 months before the next treatment, the probability of pregnancy and live birth did not improve.


Thus, while it is quite possible in natural family planning to wait two years and more until the next pregnancy, a time window of six to no more than 24 months after delivery should be considered for optimal treatment success in the case of fertility treatment.

By the way…

If you do not supply your body with suitable supplements (such as Fertilovit® For2 plus DHA) anyway while you are breastfeeding, it is important to remember that you should have adequate folic acid and other vital nutrients (for example, Fertilovit®) at least three months prior to a new cycle of fertility treatment.


Quinn et al. Decreased clinical pregnancy and live birth rates. Hum Reprod 2018; 33 (7): 1316-1321

About the author

Dr. rer. nat. Birgit Wogatzky

For many years now, biologist and nutritionist Dr Birgit Wogatzky, has been focusing on the special needs of fertility patients. For the readers of this blog, she sums up interesting novel information and developments from current research projects regarding lifestyle and nutrition of fertility patients.

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